Modification by N-acetyltransferase 1 genotype on the association between dietary heterocyclic amines and colon cancer in a multiethnic study

OBJECTIVE: Colorectal cancer incidence is greater among African Americans, compared to whites in the U.S., and may be due in part to differences in diet, genetic variation at metabolic loci, and/or the joint effect of diet and genetic susceptibility. We examined whether our previously reported associations between meat-derived heterocyclic amine (HCA) intake and colon cancer were modified by N-acetyltransferase 1 (NAT1) or 2 (NAT2) genotypes and whether there were differences by race. METHODS: In a population-based, case-control study of colon cancer, exposure to HCAs was assessed using a food-frequency questionnaire with a meat-cooking and doneness module, among African Americans (217 cases and 315 controls) and whites (290 cases and 534 controls). RESULTS: There was no association with NAT1*10 versus NAT1-non*10 genotypes for colon cancer. Among whites, there was a positive association for NAT2-"rapid/intermediate" genotype [odds ratio (OR)=1.4; 95% confidence interval (CI)=1.0, 1.8], compared to the NAT2-"slow" that was not observed among African Americans. Colon cancer associations with HCA intake were modified by NAT1, but not NAT2, regardless of race. However, the "at-risk" NAT1 genotype differed by race. For example, among African Americans, the positive association with 2-amino-1-methyl-6-phenyl-imidazo[4,5-b]pyridine (PhIP) was confined to those with NAT1*10 genotype (OR=1.8; 95% CI=1.0, 3.3; P for interaction=0.02, comparing highest to lowest intake), but among whites, an association with 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) was confined to those with NAT1-non*10 genotype (OR=1.9; 95% CI=1.1, 3.1; P for interaction=0.03). CONCLUSIONS: Our data indicate modification by NAT1 for HCA and colon cancer associations, regardless of race. Although the at-risk NAT1 genotype differs by race, the magnitude of the individual HCA-related associations in both race groups are similar. Therefore, our data do not support the hypothesis that NAT1 by HCA interactions contribute to differences in colorectal cancer incidence between African Americans and whites.     

Deciphering the ancient and complex evolutionary history of human arylamine N-acetyltransferase genes

The human N-acetyltransferase genes NAT1 and NAT2 encode two phase-II enzymes that metabolize various drugs and carcinogens. Functional variability at these genes has been associated with adverse drug reactions and cancer susceptibility. Mutations in NAT2 leading to the so-called slow-acetylation phenotype reach high frequencies worldwide, which questions the significance of altered acetylation in human adaptation. To investigate the role of population history and natural selection in shaping NATs variation, we characterized genetic diversity through the resequencing and genotyping of NAT1, NAT2, and the pseudogene NATP in a collection of 13 different populations with distinct ethnic backgrounds and demographic pasts. This combined study design allowed us to define a detailed map of linkage disequilibrium of the NATs region as well as to perform a number of sequence-based neutrality tests and the long-range haplotype (LRH) test. Our data revealed distinctive patterns of variability for the two genes: the reduced diversity observed at NAT1 is consistent with the action of purifying selection, whereas NAT2 functional variation contributes to high levels of diversity. In addition, the LRH test identified a particular NAT2 haplotype (NAT2*5B) under recent positive selection in western/central Eurasians. This haplotype harbors the mutation 341T-->C and encodes the "slowest-acetylator" NAT2 enzyme, suggesting a general selective advantage for the slow-acetylator phenotype. Interestingly, the NAT2*5B haplotype, which seems to have conferred a selective advantage during the past approximately 6,500 years, exhibits today the strongest association with susceptibility to bladder cancer and adverse drug reactions. On the whole, the patterns observed for NAT2 well illustrate how geographically and temporally fluctuating xenobiotic environments may have influenced not only our genome variability but also our present-day susceptibility to disease.     

CYP1A1, CYP2D6, CYP2E1, NAT2, GSTM1 and GSTT1 polymorphisms or their combinations are associated with the increased risk of the laryngeal squamous cell carcinoma

Polymorphisms in the selected genes controlling carcinogen metabolism (CYP1A1, CYP2D6, CYP2E1, NAT2, GSTM1, GSTT1) considered separately or in different combinations, were investigated for an association with tobacco smoke-associated squamous cell carcinoma (SCC) of the larynx. The case-control study was performed in 289 patients with laryngeal SCC and in 316 cancer-free controls; all were Caucasian males from the same region of Poland and current tobacco smokers. The DNA samples were genotyped using PCR-RFLP and multiplex PCR. The variants' frequencies in both groups were compared; odds ratios and their 95% confidence intervals were calculated by logistic regression analyses. The CYP1A1*1/*4, CYP2D6*4/*4, NAT2*4/*6A genotypes, as well as the CYP1A1*4, CYP2D6*4 and NAT2*4 alleles, were found at significantly higher frequencies in cases than in controls indicating their role as "risk-elevating" factors in laryngeal SCC. Combined genotypes, characterized by the presence of the "risk-elevating" variants at more than one locus, often occurred together with the null variant of the GSTM1 gene and homozygous XPD A/A (Lys751Gln, A35931C) genotype. Furthermore, we identified some "protective" variants, found more frequently in controls than in cases, i.e. the NAT2*6A/*6A and NAT2*5B/*6A genotypes. A distribution of "risk" or "protection" genotypes/alleles seems to be connected with age as an occurrence or risk genes was more frequent in the group of "young" cases (< or = 49 years). Accumulation of certain alleles or genotypes of the CYP1A1, NAT2, GSTM1 and XPD seems to be associated with either increased or decreased risk to develop laryngeal SCC. Therefore, polymorphisms in these genes may play a role in the laryngeal cancer etiology.     

CTLA4 is differentially associated with autoimmune diseases in the Dutch population

Cytotoxic T lymphocyte-associated antigen 4 (CTLA4) is an important negative regulator of T-cell response and its genetic association with type 1 diabetes (T1D) has recently been demonstrated. The frequent co-association of autoimmune diseases (AID) and the implication from multiple genome scans that the CTLA4 gene region is a general autoimmune region, led us to study the role of CTLA4 in independent cohorts of T1D, coeliac disease (CD) and rheumatoid arthritis (RA) patients. We present independent data that confirm the association of CTLA4 in Dutch patients with juvenile onset T1D and show differential association of CTLA4 with CD and RA. The CTLA4 gene polymorphisms were tested for association in 350 T1D, 310 CD, 520 RA patients and 900 controls. In addition, 218 families were tested by the transmission disequilibrium test (TDT). T1D patients showed the highest association with the MH30*G: −1147*C: +49*G: CT60*G: JO37_3*G (haplotype 2) in both a case/control cohort (P=0.002, OR=1.42) and by TDT (P=0.02, OR=1.43). In contrast, this haplotype showed no association in the RA and CD cohorts. However, we observed an increased frequency of the MH30*G: −1147*T: +49*A: CT60*G: JO37_3*A (haplotype 3) in the CD patients diagnosed at a young age (OR=1.6, P=0.026, P _c=0.052). Furthermore, when T1D and CD patients were stratified based on the HLA risk, the T1D susceptible CTLA4 haplotype 2 was over-represented in the high HLA-risk T1D and CD groups. In conclusion, we confirmed association between CTLA4 haplotype 2 and T1D in the Dutch population. Association with another CTLA4 haplotype (haplotype 3) was confirmed for CD, but only in those patients who had an early age of expression. No effect was found between RA and CTLA4. The association of the CTLA4 haplotype 2 with the high-risk HLA genotype in T1D and CD, which share DQ2 as the one of high-risk alleles, might provide a clue to understanding the common genetic background of AID.Electronic Supplementary Material Supplementary material is available for this article at An erratum to this article can be found at     

Detailed analysis of the variability of peptidylarginine deiminase type 4 in German patients with rheumatoid arthritis: a case-control study

Peptidylarginine deiminase type 4 (PADI4) genotypes were shown to influence susceptibility to rheumatoid arthritis (RA) in the Japanese population. Such an association could not previously be confirmed in different European populations. In the present study, we analysed exons 2-4 of PADI4 in 102 German RA patients and 102 healthy individuals to study the influence of PADI4 variability on RA susceptibility by means of haplotype-specific DNA sequencing. Analyses of the influence of PADI4 and HLA-DRB1 genotypes on disease activity and on levels of anti-cyclic citrullinated peptide antibodies were performed. Comparing the frequencies of PADI4 haplotype 4 (padi4_89*G, padi4_90*T, padi4_92*G, padi4_94*T, padi4_104*C, padi4_95*G, padi4_96*T) (patients, 14.7%; controls, 7.8%; odds ratio = 2.0, 95% confidence interval = 1.1-3.8) and carriers of this haplotype (patients, 27.5%; controls, 13.7%; odds ratio = 2.4, 95% confidence interval = 1.2-4.8), a significant positive association of PADI4 haplotype 4 with RA could be demonstrated. Other PADI4 haplotypes did not differ significantly between patients and controls. Regarding the individual PADI4 variants, padi4_89 (A-->G), padi4_90 (C-->T), and padi4_94 (C-->T) were significantly associated with RA (patients, 49.5%; controls, 38.7%; odds ratio = 1.6, 95% confidence interval = 1.1-2.3). Considering novel PADI4 variants located in or near to exons 2, 3, and 4, no quantitative or qualitative differences between RA patients (8.8%) and healthy controls (10.8%) could be demonstrated. While the PADI4 genotype did not influence disease activity and the anti-cyclic citrullinated peptide antibody level, the presence of the HLA-DRB1 shared epitope was significantly associated with higher anti-cyclic citrullinated peptide antibody levels (P = 0.033). The results of this small case-control study support the hypothesis that variability of the PADI4 gene may influence susceptibility to RA in the German population. Quantitative or qualitative differences in previously undefined PADI4 variants between patients and controls could not be demonstrated.     

Polymorphisms of arylamine N-acetyltransferase2 and risk of lung and colorectal cancer

The arylamine N-acetyltransferase 2 (NAT2) enzymes detoxify a wide range of naturally occurring xenobiotics including carcinogens and drugs. Point mutations in the NAT2 gene result in the variant alleles M1 (NAT2 *5A), M2 (NAT2*6A), M3 (NAT2*7) and M4 (NAT2 *14A) from the wild-type WT (NAT2 *4) allele. The current study was aimed at screening genetic polymorphisms of NAT2 gene in 49 lung cancer patients, 54 colorectal cancer patients and 99 cancer-free controls, using PCR-RFLP. There were significant differences in allele frequencies between lung cancer patients and controls in the WT, M2 and M3 alleles (p < 0.05). However, only M2 and M3 allele frequencies were different between colorectal cancer patients and controls (p < 0.05). There was a marginal significant difference in the distribution of rapid and slow acetylator genotypes between lung cancer patients and controls (p = 0.06 and p = 0.05, respectively), but not between colorectal cancer patients and controls (p = 1.0 and p = 0.95, respectively). Risk of lung cancer development was found to be lower in slow acetylators [odds ratio (OR): 0.51, 95% confidence interval (95% CI): 0.25, 1.02, p-value = 0.07]. No effect was observed in case of colorectal cancer. Our results showed that NAT2 genotypes and phenotypes might be involved in lung cancer but not colorectal cancer susceptibility in Jordan.     

Imbalance between Th17 and regulatory T-cells in systemic lupus erythematosus

Impaired function of regulatory T-cells (Treg) leads to a failure in immune tolerance and triggers autoimmunity. We analyzed whether the deficiency in Treg in systemic lupus erythematosus (SLE) is accompanied by an increase in effector T-cell responses. We studied the frequencies of IL-17A (Th17) and IFNg (Th1) producing CD4(+) T-cells by flow cytometric detection of intracellular cytokines in PMA/ionomycin stimulated blood lymphocytes from seven patients with active SLE, eight with SLE in remission, and 11 healthy controls. Circulating Treg were evaluated as CD4(+)CD25(+) lymphocytes expressing FoxP3. There was no difference in the percentage of Treg cells between the groups, but their absolute counts were decreased in active SLE (5 [1-7] cells/μL) compared to inactive SLE (11 [6-15]; p = 0.05) and healthy controls (16 [10-20]; p 〈 0.01). Both the frequency and numbers of Th1 cells were decreased in SLE compared to controls. No difference was observed in the number of Th17 cells, which resulted in a decreased Th1/Th17 ratio. In parallel, a higher Treg/Th17 ratio in healthy controls (2.2 [1.8-3.6]) compared to active SLE (1.1 [1.0-2.1]; p 〈 0.05) was observed. There was a correlation between the number of Treg cells and disease activity status (SLEDAI, r = -0.59). SLE patients in the active phase of the disease are characterized by a deficiency in Treg cells and decreased Treg/Th17 ratio. This suggests that the imbalance between major T-cells subsets might be responsible for an increased proinflammatory response in the exacerbation of SLE.     

N-acetyltransferase 2 gene polymorphism in patients with colorectal carcinoma

The acetylation polymorphism is a common inherited variation in human drug and carcinogen metabolism. Because N- acetyltransferase (NAT2) is important for the detoxification and/or bioactivation of drugs and carcinogens, polymorphisms of this gene have important implications in therapeutics of and susceptibility to cancer. In this study, NAT2 genotype (NAT2*5A (C(481)T), NAT2*6A (G(590)A), NAT2*7A/B (G(857)A)) and NAT2*14A (G(191)A) and phenotype were determined in 125 patients with colorectal carcinoma and 82 healthy control in Mersin, a city located in the southern region of Turkey. Isolation of the subjects' DNA was performed by using a highly purified PCR template preparation kit/(Roche Diagnostics cat. no: 1 796 828) and the NAT2 polymorphism was detected using real-time PCR (Roche Diagnostics, GmbH, Mannheim, Germany). According to this study high protein intake is associated with the increased risk for the development of colon cancer (OR = 1.73; 95% CI, 1.10-3.07). Although only NAT2*14A fast type was associated with increased risk in patients with colorectal carcinoma (OR = 3.03; 95% CI, 1.56-5.86), when a high protein diet was considered, NAT2*7A/B fast genotype was also found to be associated with an increased risk (OR = 2.06, 95% CI for NAT2*7A/B, 1.10-3.86; OR = 2.65; 95% CI, 1.29-5.46 for NAT2*14A). Smoking status did not differ between the control and patient groups. Our data suggest that exposure to carcinogens through consumption of a high-protein diet may increase the risk of colorectal carcinoma only in genetically-susceptible individuals.     

Simultaneous determination of polymorphism in N-acetyltransferase 1 and 2 genes by reverse line blot hybridization

Polymorphism in N-acetyltransferases NAT1 and NAT2 may contribute to differences in cancer susceptibility of subjects exposed to alkylating compounds. We developed a robust method for simultaneous determination of these NAT polymorphisms: Reverse line blot (RLB) hybridization, based on PCR followed by allele-specific oligo hybridization. On a membrane, allele-specific oligonucleotide probes of the NAT genes (NAT1*4, *3, *10, *11 and NAT2*4, *5, *6, *7, *12) were applied in lines. After separate amplification of the NAT genes, simultaneous hybridization of these products in lines perpendicular to the lines with oligonucleotide probes was performed, followed by nonradioactive detection. This resulted in hybridization patterns, representing the NAT genotype of an individual. RLB hybridizations were conducted on DNA from 240 Dutch Caucasian participants in an ongoing case-control study on colorectal adenoma (including 126 polyp-free control subjects). Results were in complete agreement with those obtained by commonly used methods, i.e., allele-specific PCR and PCR-RFLP. Allele-frequencies in the polyp-free control group were similar to those described in the literature. RLB hybridization is, however, considerably faster and cheaper than the common assays. Moreover, expansion with allelic variants of other genes is relatively easy, which makes RLB hybridization very useful for multiplex analysis of numerous polymorphisms in epidemiological studies.     

N-acetyltransferase 2 polymorphism in patients with diabetes mellitus

The arylamine N-acetyltransferases (NATs) are a unique family of enzymes that catalyse the transfer of an acetyl group from acetyl-CoA to the terminal nitrogen of hydrazine and arylamine drugs and carcinogens. Human arylamine NATs are known to exist as two isoenzymes, NAT1 and NAT2. The objective of this study was to identify whether the genetic polymorphism of NAT2 plays a role in susceptibility to Diabetes Mellitus (DM). Ninety-seven patients with DM and 104 healthy controls were enrolled in the study. NAT2*5A, NAT2*6A, NAT2*7A/B and NAT2*14A polymorphisms were detected by using real time PCR with LightCycler (Roche Diagnostics GmbH, Mannheim, Germany). According to our data, the NAT2*5A and NAT2*6A mutant genotypes and NAT2*14A heterozygous genotype were associated with an increased risk of development of DM (OR = 47.06; 95%CI: 10.55-209.77 for NAT 2*5A, OR = 18.48; 95%CI: 3.83-89.11 for NAT2*6A and OR = 18.22; 95%CI: 6.29-52.76 for NAT2*14A). However, the NAT2*7A/B gene polymorphism carried no increased risk for developing DM disease. After grouping according to phenotypes as either slow or fast acetylators, NAT2*6A slow acetylator was found to be a significant risk factor for DM (OR = 6.09; 95%CI: 1.99-18.6, p = 0.02). The results indicate that NAT2 slow acetylator genotypes may be an important genetic determinant for DM in the Turkish population.     

Autoimmune-prone mice share a promoter haplotype associated with reduced expression and function of the Fc receptor FcgammaRII

Human autoimmune diseases thought to arise from the combined effects of multiple susceptibility genes include systemic lupus erythematosus (SLE) and autoimmune diabetes. Well-characterised polygenic mouse models closely resembling each of these diseases exist, and genetic evidence links receptors for the Fc portion of immunoglobulin G (FcR) with their pathogenesis in mice and humans [1] [2] [3]. FcRs may be activatory or inhibitory and regulate a variety of immune and inflammatory processes [4] [5]. FcgammaRII (CD32) negatively regulates activation of cells including B cells and macrophages [6]. FcgammaRII-deficient mice are prone to immune-mediated disease [7] [8] [9]. The gene encoding FcgammaRII, Fcgr2, is contained in genetic susceptibility intervals in mouse models of SLE such as the New Zealand Black (NZB) contribution to the (NZB x New Zealand White (NZW)) F1 strain [1] [10] [11] and the BXSB strain [12], and in human SLE [1] [2] [3]. We therefore sequenced Fcgr2 and identified a haplotype defined by deletions in the Fcgr2 promoter region that is present in major SLE-prone mouse strains (NZB, BXSB, SB/Le, MRL, 129 [13]) and non-obese diabetic (NOD) mice but absent in control strains (BALB/c, C57BL/6, DBA/2, C57BL/10) and NZW mice. The autoimmune haplotype was associated with reduced cell-surface expression of FcgammaRII on macrophages and activated B cells and with hyperactive macrophages resembling those of FcgammaRII-deficient mice, and is therefore likely to play an important role in the pathogenesis of SLE and possibly diabetes.     

Arylamine N-acetyltransferase 2 genotypes in a Mexican population

The acetylating activity of N-acetyltransferase 2 (NAT2) has critical implications for therapeutics and disease susceptibility. To date, several polymorphisms that alter the enzymatic activity and/or protein stability of NAT2 have been identified. We examined the distribution and frequency of NAT2 genotypes in the Mexican population. Among 250 samples amplified and sequenced for the NAT2 gene, we found seven different SNPs; the most frequent allele was 803 A>G (35.8%), followed by 282 C>T, 341 T>C, and 481 C>T. There were no differences in the distribution of SNPs between healthy subjects and cancer patients. These eight polymorphisms defined 26 diplotypes; 11.6% were wild type (NAT2*4/NAT2*4), while the most common diplotype was NAT2*4/NAT2*5B, present in 17.2%. We did not identify other common polymorphisms. The results were compared with the NAT2 SNPs reported from other populations. All but the Turkish population was significantly different from ours. We conclude that the mixed-race Mexican population requires special attention because NAT2 genotype frequencies differ from those in other regions of the world.     

Lack of Association of the N-acetyltransferase NAT1*10 Allele with Prostate Cancer Incidence, Grade, or Stage Among Smokers in Finland

Genetic variations in xenobiotic metabolizing genes can influence susceptibility to many environmentally induced cancers. Inheritance of the N-acetyltransferase 1 allele (NAT1*10), linked with increased metabolic activation of pro-carcinogens, is associated with an increased susceptibility to many cancers in which cigarette- or meat-derived carcinogens have been implicated in their etiology. The role of NAT1*10 in prostate cancer is under studied. Although cigarette smoking is not considered a risk factor for prostate cancer, a recent review suggests it may play a role in disease progression. Consequently, we examined the association of NAT1*10 with prostate cancer risk, grade, and stage among 400 Finnish male smokers using a case-control study design. Following genotyping of 206 patients and 196 healthy controls, our results do not support the role of NAT1*10 in relation to prostate cancer risk (OR?=?1.28; 95% CI, 0.66-2.47), aggressive disease (OR?=?0.58; 95% CI, 0.13-2.67), or advanced disease (OR?=?1.19; 95% CI, 0.49-2.91).     

N-acetyltransferase 1 and 2 gene sequence variants and risk of head and neck cancer

Polymorphisms that alter the function of genes involved in the activation or detoxification of carcinogenic compounds can influence an individuals risk of developing cancer. Polymorphic changes modulating the acetylation capacity of the N-acetyltransferase (NAT) genes have been implicated in the risk of developing cancer. In this study the role of genetically determined individual NAT1 and NAT2 genotypes, haplotypes and haplotype combinations in the predisposition to head and neck cancer was investigated. Polymorphic regions of the NAT1 and NAT2 genes were analyzed in patients with head and neck cancer and healthy individuals by polymerase chain reaction-restriction fragment length polymorphism. Distribution of the genotypes, allele frequencies, diplotypes and haplotypes and correlation with clinical characteristics were evaluated. No association was observed between the NAT1*3, NAT1*10, NAT1*11, NAT2*5 and NAT2*6 genotypes and risk of head and neck cancer. The NAT2*7 slow genotype was associated with reduced risk of disease. A significant association was observed between the fast acetylator NAT2*4/NAT1*10 diplotype and risk of head and neck cancer. Combined haplotypes harboring the T1088A and C1095A variants characterizing the NAT1*10 allele were associated with increased risk. Our results suggest that NAT1 and NAT2 gene combinations may influence the risk of developing head and neck cancer.     

One-year health status outcomes of unstable angina versus myocardial infarction: a prospective, observational cohort study of ACS survivors

Background

Unstable angina (UA) patients have lower mortality and reinfarction risks than ST-elevation (STEMI) or non-ST elevation myocardial infarction (NSTEMI) patients and, accordingly, receive less aggressive treatment. Little is known, however, about the health status outcomes (angina, physical function, and quality of life) of UA versus MI patients among survivors of an ACS hospitalization.

Methods

In a cohort of 1,192 consecutively enrolled ACS survivors from two Kansas City hospitals, we evaluated the associations between ACS presentation (UA, NSTEMI, and STEMI) and one-year health status (angina, physical functioning and quality of life), one-year cardiac rehospitalization rates, and two-year mortality outcomes, using multivariable regression modeling.

Results

After multivariable adjustment for demographic, hospital, co-morbidity, baseline health status, and treatment characteristics, UA patients had a greater prevalence of angina at 1 year than STEMI patients (adjusted relative risk [RR] = 1.42; 95% CI [1.06, 1.90]) and similar rates as NSTEMI patients (adjusted RR = 1.1; 95% CI [0.85, 1.42]). In addition, UA patients fared no better than MI patients in Short Form-12 physical component scores (UA vs. STEMI score difference -0.05 points; 95% CI [-2.41, 2.3]; UA vs. NSTEMI score difference -1.91 points; 95% CI [-4.01, 0.18]) or Seattle Angina Questionnaire quality of life scores (UA vs. STEMI score difference -1.39 points; 95% CI [-5.63, 2.85]; UA vs. NSTEMI score difference -0.24 points 95% CI [-4.01, 3.54]). Finally, UA patients had similar rehospitalization rates as MI patients (UA vs. STEMI adjusted hazard ratio [HR] = 1.31; 95% CI [0.86, 1.99]; UA vs. NSTEMI adjusted HR = 1.03; 95% CI [0.73, 1.47]), despite better 2-year survival (UA vs. STEMI adjusted HR = 0.51; 95% confidence interval (CI) [0.28, 0.95]; UA vs. NSTEMI adjusted HR = 0.40; 95% CI [0.24, 0.65]).

Conclusion

Although UA patients have better survival rates, they have similar or worse one-year health status outcomes and cardiac rehospitalization rates as compared with MI patients. Clinicians should be aware of the adverse health status outcome risks for UA patients and consider close monitoring for the opportunity to improve their health status and minimize the need for subsequent rehospitalization.     

Polymorphism of the tumor necrosis factor beta gene in systemic lupus erythematosus: TNFB-MHC haplotypes

We investigated the Nco I restriction fragment length polymorphism (RFLP) of the tumor necrosis factor beta (TNFB) gene in 173 patients with systemic lupus erythematosus (SLE), 192 unrelated healthy controls, and eleven panel families, all of German origin. The phenotype frequency of the TNFB*1 allele was significantly increased in patients compared to controls (63.6% vs 47.1%, RR = 1.96, p <0.002). The results of a two-point haplotype statistical analysis between TNFB and HLA alleles show that there is linkage disequilibrium between TNFB*1 and HLA-A1, Cw7, B8, DR3, DQ2, and C4A DE. The frequency of TNFB*1 was compared in SLE patients and controls in the presence or absence of each of these alleles. TNFB*1 is increased in patients over controls only in the presence of the mentioned alleles. Therefore, the whole haplotype A1, Cw7, B8, TNFB*1, C4A DE, DR3, DQ2 is increased in patients and it cannot be determined which of the genes carried by this haplotype is responsible for the susceptibility to SLE. In addition, two-locus associations were analyzed in 192 unrelated healthy controls for TNFB and class I alleles typed by serology, and for TNFB and class II alleles typed by polymerase chain reaction/oligonucleotide probes. We found positive linkage disequilibrium between TNFB*1 and the following alleles: HLA-A24, HLA-B8, DRB1*0301, DRB1*1104, DRB1*1302, DQA1*0501, DQB1*0201, DQB1*0604, and DPB1*0101. TNFB*2 is associated with HLA-B7, DRB1*1501, and DQB1*0602.This study was supported by grants from the Federal Ministry of Research and Technology (BMFT/DFVLR, 01 VM 8608/9), the German Academic Exchange Service (DAAD, 322/501/014/0), and SFB (217).This work is part of the doctoral thesis of M. P. Bettinotti.     

Immunogenicity and Safety of Influenza Vaccination in Systemic Lupus Erythematosus Patients Compared with Healthy Controls: A Meta-Analysis

Objective

To assess the immunogenicity and safety of influenza vaccine in patients with systemic lupus erythematosus (SLE).

Methods

Relevant articles were retrieved from electronic databases. Seroprotection rate, seroconversion rate and factors that increase antibody geometric mean titer (GMT) were used as indices to measure the immunogenicity. The safety of vaccine was assessed through monitoring adverse events, which included side effects and SLE exacerbations. We performed a meta-analysis of influenza vaccine seroprotection, seroconversion and adverse effects. SLE exacerbation after vaccination was comprehensively described. We used the Committee for Proprietary Medicinal Products (CPMP) guidelines to determine whether influenza can induce adequate immunogenicity in patients with SLE.

Results

Eighteen studies with 1966 subjects met the inclusion criteria. At least 565 of the subjects were patients with low-to-moderate SLE Disease Activity Index (SLEDAI) score or stable SLE disease. Compared with the general population, seroprotection rate in SLE patients was significantly decreased in patients with H1N1 [odds ratio (OR) = 0.36, 95% confidence interval (CI): 0.27–0.50] and H3N2 vaccination (OR = 0.48, 95% CI: 0.24–0.93), but not influenza B vaccination (OR = 0.55, 95% CI: 0.24–1.25). Seroconversion rate also significantly decreased in patients with H1N1 (OR = 0.39, 95% CI: 0.27–0.57) and influenza B (OR = 0.47, 95% CI: 0.29–0.76) vaccination, but not H3N2 vaccination (OR = 0.62, 95% CI: 0.21–1.79). However, the immunogenicity of influenza vaccine in SLE patients almost reached that of the CPMP guidelines. The OR for side effects (patients versus healthy controls) was 3.24 (95% CI: 0.62–16.76). Among 1966 patients with SLE, 32 experienced mild exacerbation of SLE and five had serious side effects for other reasons.

Conclusion

Influenza vaccine has moderate effect on protecting patients with SLE. The side effects of influenza vaccine are not serious and are manageable. With consideration of a higher risk of SLE exacerbation and a more severe course of infection among SLE patients, influenza vaccination should be promoted among SLE patients with a low-to-moderate SLEDAI score or stable disease.     

The burden of traumatic brain injury from low-energy falls among patients from 18 countries in the CENTER-TBI Registry: A comparative cohort study

BackgroundTraumatic brain injury (TBI) is an important global public health burden, where those injured by high-energy transfer (e.g., road traffic collisions) are assumed to have more severe injury and are prioritised by emergency medical service trauma triage tools. However recent studies suggest an increasing TBI disease burden in older people injured through low-energy falls. We aimed to assess the prevalence of low-energy falls among patients presenting to hospital with TBI, and to compare their characteristics, care pathways, and outcomes to TBI caused by high-energy trauma.Methods and findingsWe conducted a comparative cohort study utilising the CENTER-TBI (Collaborative European NeuroTrauma Effectiveness Research in TBI) Registry, which recorded patient demographics, injury, care pathway, and acute care outcome data in 56 acute trauma receiving hospitals across 18 countries (17 countries in Europe and Israel). Patients presenting with TBI and indications for computed tomography (CT) brain scan between 2014 to 2018 were purposively sampled. The main study outcomes were (i) the prevalence of low-energy falls causing TBI within the overall cohort and (ii) comparisons of TBI patients injured by low-energy falls to TBI patients injured by high-energy transfer—in terms of demographic and injury characteristics, care pathways, and hospital mortality. In total, 22,782 eligible patients were enrolled, and study outcomes were analysed for 21,681 TBI patients with known injury mechanism; 40% (95% CI 39% to 41%) (8,622/21,681) of patients with TBI were injured by low-energy falls. Compared to 13,059 patients injured by high-energy transfer (HE cohort), the those injured through low-energy falls (LE cohort) were older (LE cohort, median 74 [IQR 56 to 84] years, versus HE cohort, median 42 [IQR 25 to 60] years; p < 0.001), more often female (LE cohort, 50% [95% CI 48% to 51%], versus HE cohort, 32% [95% CI 31% to 34%]; p < 0.001), more frequently taking pre-injury anticoagulants or/and platelet aggregation inhibitors (LE cohort, 44% [95% CI 42% to 45%], versus HE cohort, 13% [95% CI 11% to 14%]; p < 0.001), and less often presenting with moderately or severely impaired conscious level (LE cohort, 7.8% [95% CI 5.6% to 9.8%], versus HE cohort, 10% [95% CI 8.7% to 12%]; p < 0.001), but had similar in-hospital mortality (LE cohort, 6.3% [95% CI 4.2% to 8.3%], versus HE cohort, 7.0% [95% CI 5.3% to 8.6%]; p = 0.83). The CT brain scan traumatic abnormality rate was 3% lower in the LE cohort (LE cohort, 29% [95% CI 27% to 31%], versus HE cohort, 32% [95% CI 31% to 34%]; p < 0.001); individuals in the LE cohort were 50% less likely to receive critical care (LE cohort, 12% [95% CI 9.5% to 13%], versus HE cohort, 24% [95% CI 23% to 26%]; p < 0.001) or emergency interventions (LE cohort, 7.5% [95% CI 5.4% to 9.5%], versus HE cohort, 13% [95% CI 12% to 15%]; p < 0.001) than patients injured by high-energy transfer. The purposive sampling strategy and censorship of patient outcomes beyond hospital discharge are the main study limitations.ConclusionsWe observed that patients sustaining TBI from low-energy falls are an important component of the TBI disease burden and a distinct demographic cohort; further, our findings suggest that energy transfer may not predict intracranial injury or acute care mortality in patients with TBI presenting to hospital. This suggests that factors beyond energy transfer level may be more relevant to prehospital and emergency department TBI triage in older people. A specific focus to improve prevention and care for patients sustaining TBI from low-energy falls is required.

In a cohort study, Fiona Lecky and colleagues investigate the factors associated with traumatic brain injury resulting from low energy falls compared with injuries from high energy transfer mechanisms among patients across Europe and Israel.     

A promoter haplotype of the immunoreceptor tyrosine-based inhibitory motif-bearing FcgammaRIIb alters receptor expression and associates with autoimmunity. I. Regulatory FCGR2B polymorphisms and their association with systemic lupus erythematosus

FcgammaRIIb, the immunoreceptor tyrosine-based inhibitory motif-containing receptor for IgG (Mendelian Inheritance in Man no. 604590), plays an important role in maintaining the homeostasis of immune responses. We have identified 10 novel single-nucleotide polymorphisms in the promoter region of human FCGR2B gene and characterized two functionally distinct haplotypes in its proximal promoter. In luciferase reporter assays, the less frequent promoter haplotype leads to increased expression of the reporter gene in both B lymphoid and myeloid cell lines under constitutive and stimulated conditions. Four independent genome-wide scans support linkage of the human FcgammaR region to the systemic lupus erythematosus (SLE; Online Mendelian Inheritance in Man no. 152700) phenotype. Our case-control study in 600 Caucasians indicates a significant association of the less frequent FCGR2B promoter haplotype with the SLE phenotype (odds ratio = 1.65; p = 0.0054). The FCGR2B haplotype has no linkage disequilibrium with previously identified FCGR2A and FCGR3A polymorphisms, and after adjustment for FCGR2A and FCGR3A, FCGR2B showed a persistent association with SLE (odds ratio = 1.72; p = 0.0083). These results suggest that an expression variant of FCGR2B is a risk factor for human lupus and implicate FCGR2B in disease pathogenesis.