深部真菌病相关免疫重建综合征

机体的免疫力在清除感染微生物中起重要作用。免疫功能恢复或免疫失衡(包括免疫反应不足和免疫反应过度)都会对机体产生损害。免疫重建综合征(IRS)是指原有免疫抑制状态迅速缓解所激发的一系列免疫反应,导致局限性和系统性的表现,它常被误判为抗真菌治疗的失败。目前快速、强效免疫调节剂在临床中广泛使用,IRS逐渐被人们认识。IRS的概念强调免疫失调及过度免疫反应会对机体造成损害,但在内源性抗感染免疫反应不足的情况下,给予适当的免疫调节治疗也是必要的。     

Clinical features and serum biomarkers in HIV immune reconstitution inflammatory syndrome after cryptococcal meningitis: a prospective cohort study

Background

Although antiretroviral therapy (ART) improves survival in persons with cryptococcal meningitis (CM) and AIDS, ART frequently elicits HIV immune reconstitution inflammatory syndrome (IRIS), an exaggerated and frequently deadly inflammatory reaction that complicates recovery from immunodeficiency. The pathogenesis of IRIS is poorly understood and prediction of IRIS is not possible.

Methods and Findings

We prospectively followed 101 ART-naïve Ugandans with AIDS and recent CM for one year after initiating ART, and used Luminex multiplex assays to compare serum cytokine levels in participants who did or did not develop IRIS. IRIS occurred in 45% of participants with recent CM on ART, including 30% with central nervous system (CNS) manifestations. The median time to CM-IRIS was 8.8 wk on ART. Overall mortality on ART was 36% with IRIS and 21% without IRIS. CM-IRIS was independently associated with death (HR = 2.3, 95% CI 1.1–5.1, p = 0.04). Patients experiencing subsequent CM-IRIS had 4-fold higher median serum cryptococcal antigen (CRAG) levels pre-ART (p = 0.006). Higher pre-ART levels of interleukin (IL)-4 and IL-17 as well as lower tumor necrosis factor (TNF)-α, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and vascular endothelial growth factor (VEGF) predicted future IRIS in multivariate analyses (area under the curve [AUC] = 0.82). An algorithm based on seven pre-ART serum biomarkers was a robust tool for stratifying high (83%), moderate (48%), and low risk (23%) for IRIS in the cohort. After ART was initiated, increasing levels of C-reactive protein (CRP), D-dimer, IL-6, IL-7, IL-13, G-CSF, or IL-1RA were associated with increasing hazard of IRIS by time-to-event analysis (each p≤0.001). At the time of IRIS onset, multiple proinflammatory cytokine responses were present, including CRP and IL-6. Mortality was predicted by pre-ART increasing IL-17, decreasing GM-CSF, and CRP level >32 mg/l (highest quartile). Pre-ART CRP level >32 mg/l alone was associated with future death (OR = 8.3, 95% CI 2.7–25.6, p<0.001).

Conclusions

Pre-ART increases in Th₁₇ and Th₂ responses (e.g., IL-17, IL-4) and lack of proinflammatory cytokine responses (e.g., TNF-α, G-CSF, GM-CSF, VEGF) predispose individuals to subsequent IRIS, perhaps as biomarkers of immune dysfunction and poor initial clearance of CRAG. Although requiring validation, these biomarkers might be an objective tool to stratify the risk of CM-IRIS and death, and could be used clinically to guide when to start ART or use prophylactic interventions. Please see later in the article for the Editors'' Summary     

Costs associated with low birth weight in a rural area of Southern Mozambique

Background

Low Birth Weight (LBW) is prevalent in low-income countries. Even though the economic evaluation of interventions to reduce this burden is essential to guide health policies, data on costs associated with LBW are scarce. This study aims to estimate the costs to the health system and to the household and the Disability Adjusted Life Years (DALYs) arising from infant deaths associated with LBW in Southern Mozambique.

Methods and Findings

Costs incurred by the households were collected through exit surveys. Health system costs were gathered from data obtained onsite and from published information. DALYs due to death of LBW babies were based on local estimates of prevalence of LBW (12%), very low birth weight (VLBW) (1%) and of case fatality rates compared to non-LBW weight babies [for LBW (12%) and VLBW (80%)]. Costs associated with LBW excess morbidity were calculated on the incremental number of hospital admissions in LBW babies compared to non-LBW weight babies. Direct and indirect household costs for routine health care were 24.12 US$ (CI 95% 21.51; 26.26). An increase in birth weight of 100 grams would lead to a 53% decrease in these costs. Direct and indirect household costs for hospital admissions were 8.50 US$ (CI 95% 6.33; 10.72). Of the 3,322 live births that occurred in one year in the study area, health system costs associated to LBW (routine health care and excess morbidity) and DALYs were 169,957.61 US$ (CI 95% 144,900.00; 195,500.00) and 2,746.06, respectively.

Conclusions

This first cost evaluation of LBW in a low-income country shows that reducing the prevalence of LBW would translate into important cost savings to the health system and the household. These results are of relevance for similar settings and should serve to promote interventions aimed at improving maternal care.     

Evaluation of cellular phenotypes implicated in immunopathogenesis and monitoring immune reconstitution inflammatory syndrome in HIV/leprosy cases

Background

It is now evident that HAART-associated immunological improvement often leads to a variety of new clinical manifestations, collectively termed immune reconstitution inflammatory syndrome, or IRIS. This phenomenon has already been described in cases of HIV coinfection with Mycobacterium leprae, most of them belonging to the tuberculoid spectrum of leprosy disease, as observed in leprosy reversal reaction (RR). However, the events related to the pathogenesis of this association need to be clarified. This study investigated the immunological profile of HIV/leprosy patients, with special attention to the cellular activation status, to better understand the mechanisms related to IRIS/RR immunopathogenesis, identifying any potential biomarkers for IRIS/RR intercurrence.

Methods/Principal Findings

Eighty-five individuals were assessed in this study: HIV/leprosy and HIV-monoinfected patients, grouped according to HIV-viral load levels, leprosy patients without HIV coinfection, and healthy controls. Phenotypes were evaluated by flow cytometry for T cell subsets and immune differentiation/activation markers. As expected, absolute counts of the CD4+ and CD8+ T cells from the HIV-infected individuals changed in relation to those of the leprosy patients and controls. However, there were no significant differences among the groups, whether in the expression of cellular differentiation phenotypes or cellular activation, as reflected by the expression of CD38 and HLA-DR. Six HIV/leprosy patients identified as IRIS/RR were analyzed during IRIS/RR episodes and after prednisone treatment. These patients presented high cellular activation levels regarding the expression of CD38 in CD8+ cells T during IRIS/RR (median: 77,15%), dropping significantly (p<0,05) during post-IRIS/RR moments (median: 29,7%). Furthermore, an increase of cellular activation seems to occur prior to IRIS/RR.

Conclusion/Significance

These data suggest CD38 expression in CD8+ T cells interesting tool identifying HIV/leprosy individuals at risk for IRIS/RR. So, a comparative investigation to leprosy patients at RR should be conducted.     

Disseminated sporotrichosis with immune reconstitution inflammatory syndrome in an HIV patient: Case report and review of the literature

BackgroundSporotrichosis has been occurring as outbreaks in Brazil, reaching epidemic levels in some regions. Zoonotic transmission is the main route to acquire Sporothrix.Case reportWe describe a case of disseminated sporotrichosis caused by Sporothrix brasiliensis in an HIV/AIDS patient, with the presentation of immune reconstitution inflammatory syndrome (IRIS).ConclusionsThis case reinforces that sporotrichosis should always be suspected in patients with IRIS from endemic regions, even in patients without the typical cutaneous lesions of this mycosis.     

艾滋病免疫重建治疗策略的研究进展

获得性免疫缺陷综合征( AIDS) 是由人类免疫缺陷病毒( HIV) 侵犯并破坏机体免疫系统引起的疾病。20 世纪90 年代前, 人们普遍认为免疫系统的破坏是不可逆转的, 但自高效抗反转录病毒疗法出现以后, 发现受损的免疫功能可以获得重建并成为研究的热点。免疫功能重建是指患者受损的免疫功能恢复到正常水平或接近正常水平, 从而降低机会性感染和肿瘤的发生, 降低发病率和病死率。随着各项技术的发展和改进, AIDS 的发病机制和免疫重建机制得到进一步研究, 改善调节患者CD4⁺细胞的数量和免疫功能及细胞毒性T细胞( CTL) 的杀伤功能是最重要的保护性免疫机制。目前一些治疗新策略和手段, 如细胞因子治疗、HIV 特异性疫苗的研制已进入试验或临床阶段, 以期进一步改善患者的免疫功能。     

Immune reconstitution inflammatory syndrome: the trouble with immunity when you had none

Some individuals who are infected with HIV rapidly deteriorate shortly after starting antiretroviral therapy, despite effective viral suppression. This reaction, referred to as immune reconstitution inflammatory syndrome (IRIS), is characterized by tissue-destructive inflammation and arises as CD4(+) T cells re-emerge. It has been proposed that IRIS is caused by a dysregulation of the expanding population of CD4(+) T cells specific for a co-infecting opportunistic pathogen. Here, we argue that IRIS instead results from hyper-responsiveness of the innate immune system to T cell help, a mechanism that may be shared by the many manifestations of IRIS that occur following the reversal of other types of immunosuppression in pathogen-infected hosts.     

Use of oxfendazole to control porcine cysticercosis in a high-endemic area of Mozambique

A randomized controlled field trial to evaluate the effectiveness of a single oral dose of 30 mg/kg of oxfendazole (OFZ) treatment for control of porcine cysticercosis was conducted in 4 rural villages of Angónia district, north-western Mozambique. Two hundred and sixteen piglets aged 4 months were selected and assigned randomly to OFZ treatment or control groups. Fifty-four piglets were treated at 4 months of age (T1), while another 54 piglets were treated at 9 months of age (T2) and these were matched with 108 control pigs from the same litters and raised under the same conditions. Baseline data were collected on the prevalence of porcine cysticercosis using antigen ELISA (Ag-ELISA), as well as knowledge and practices related to Taenia solium transmission based on questionnaire interviews and observations. All animals were followed and re-tested for porcine cysticercosis by Ag-ELISA at 9 and 12 months of age when the study was terminated. Overall prevalence at baseline was 5.1% with no significant difference between groups. At the end of the study, 66.7% of the controls were found positive, whereas 21.4% of the T1 and 9.1% of the T2 pigs were positive, respectively. Incidence rates of porcine cysticercosis were lower in treated pigs as compared to controls. Necropsy of 30 randomly selected animals revealed that viable cysts were present in none (0/8) of T2 pigs, 12.5% (1/8) of T1 pigs and 42.8% (6/14) of control pigs. There was a significant reduction in the risk of T. solium cysticercosis if pigs were treated with OFZ either at 4 months (OR = 0.14; 95% CI: 0.05–0.36) or at 9 months of age (OR = 0.05; 95% CI: 0.02–0.16). Strategic treatment of pigs in endemic areas should be further explored as a means to control T. solium cysticercosis/taeniosis.     

Twinning rates in a rural area of Bangladesh

In this study we investigate the incidence of twin births over a period of 16 years in a rural area of Bangladesh using data from the Demographic Surveillance System of the International Centre for Diarrhoeal Disease Research. Over the study period twinning rates fluctuated between 7.8 and 11.2 per 1000 live births. The twinning rate was strongly correlated with maternal age; the rate for mothers over 35 years of age was about 3 times higher than for mothers younger than 20 years. The variation in twinning rate with maternal age is due to the variation in dizygotic twinning; the rate of monozygotic twinning is almost constant for all ages. Twinning rates were higher in the treatment area than in the comparison area after controlling for maternal age and parity. The rates were lower for monozygotic twinning and higher for dizygotic twinning in the treatment area than in the comparison area. Seasonality was observed for both twins and singletons, but the peak for twinning precedes that for singleton births by more than a month.     

Gender differences in immune reconstitution: a multicentric cohort analysis in sub-Saharan Africa

Background

In sub-Saharan Africa, men living with HIV often start ART at more advanced stages of disease and have higher early mortality than women. We investigated gender difference in long-term immune reconstitution.

Methods/Principal Findings

Antiretroviral-naïve adults who received ART for at least 9 months in four HIV programs in sub-Saharan Africa were included. Multivariate mixed linear models were used to examine gender differences in immune reconstitution on first line ART.A total of 21,708 patients (68% women) contributed to 61,912 person-years of follow-up. At ART start,. Median CD4 at ART were 149 [IQR 85–206] for women and 125 cells/µL [IQR 63–187] for men. After the first year on ART, immune recovery was higher in women than in men, and gender-based differences increased by 20 CD4 cells/µL per year on average (95% CI 16–23; P<0.001). Up to 6 years after ART start, patients with low initial CD4 levels experienced similar gains compared to patients with high initial levels, including those with CD4>250cells/µL (difference between patients with <50 cells/µL and those with >250 was 284 cells/µL; 95% CI 272–296; LR test for interaction with time p = 0.63). Among patients with initial CD4 count of 150–200 cells/µL, women reached 500 CD4 cells after 2.4 years on ART (95% CI 2.4–2.5) and men after 4.5 years (95% CI 4.1–4.8) of ART use.

Conclusion

Women achieved better long-term immune response to ART, reaching CD4 level associated with lower risks of AIDS related morbidity and mortality quicker than men.     

Management of myocardial infarction in a rural area

In an attempt to determine the most appropriate type of facility for the treatment of myocardial infarction in a rural community, the five-year experience of a practice serving 10,000 people is reviewed. This population is found to have a low incidence of myocardial infarction, a low death rate from the condition both in hospitalized patients and in the general population, and a low incidence of complications in the survivors. None of the deaths either in or out of hospital would likely have been prevented through the use of specialized facilities. It is concluded that no such facilities are necessary in this community and that other areas considering their acquisition should justify the need on the basis of their own experience and not on accounts in the literature.     

Lactoferrin, a key molecule in immune and inflammatory processes

Lactoferrin (Lf) belongs to the family of antimicrobial molecules that constitute the principal defense line of nonvertebrate organisms. In human immunity, their roles are considerably extended, and actually exceed mere direct antimicrobial properties. As a result, Lf is involved in both innate and adaptive immunities where its modulating effects not only help the host fight against microbes but also protect the host against harmful effects of inflammation. Such beneficial effects have been noticed in studies using dietary Lf, without the experimenters always explaining the exact modes of action of Lf. Effects on mucosal and systemic immunities are indeed often observed, which make the roles of Lf tricky to decipher. It is now known that the immunomodulatory properties of Lf are due to its ability to interact with numerous cellular and molecular targets. At the cellular level, Lf modulates the migration, maturation, and functions of immune cells. At the molecular level, in addition to iron binding, interactions of Lf with a plethora of compounds, either soluble or cell-surface molecules, account for its modulatory properties. This paper reviews our current understanding of the mechanisms that explain the regulatory properties of Lf in immune and inflammatory processes.     

Classical complement and inflammasome activation converge in CD14highCD16- monocytes in HIV associated TB-immune reconstitution inflammatory syndrome

Inflammasome-derived cytokines, IL-1β and IL-18, and complement cascade have been independently implicated in the pathogenesis of tuberculosis (TB)-immune reconstitution inflammatory syndrome (TB-IRIS), a complication affecting HIV⁺ individuals starting antiretroviral therapy (ART). Although sublytic deposition of the membrane attack complex (MAC) has been shown to promote NLRP3 inflammasome activation, it is unknown whether these pathways may cooperatively contribute to TB-IRIS. To evaluate the activation of inflammasome, peripheral blood mononuclear cells (PBMCs) from HIV-TB co-infected patients prior to ART and at the IRIS or equivalent timepoint were incubated with a probe used to assess active caspase-1/4/5 followed by screening of ASC (apoptosis-associated speck-like protein containing a CARD domain) specks as a readout of inflammasome activation by imaging flow cytometry. We found higher numbers of monocytes showing spontaneous caspase-1/4/5⁺ASC-speck formation in TB-IRIS compared to TB non-IRIS patients. Moreover, numbers of caspase-1/4/5⁺ASC-speck⁺ monocytes positively correlated with IL-1β/IL-18 plasma levels. Besides increased systemic levels of C1q and C5a, TB-IRIS patients also showed elevated C1q and C3 deposition on monocyte cell surface, suggesting aberrant classical complement activation. A clustering tSNE analysis revealed TB-IRIS patients are enriched in a CD14^highCD16^- monocyte population that undergoes MAC deposition and caspase-1/4/5 activation compared to TB non-IRIS patients, suggesting complement-associated inflammasome activation during IRIS events. Accordingly, PBMCs from patients were more sensitive to ex-vivo complement-mediated IL-1β secretion than healthy control cells in a NLRP3-dependent manner. Therefore, our data suggest complement-associated inflammasome activation may fuel the dysregulated TB-IRIS systemic inflammatory cascade and targeting this pathway may represent a novel therapeutic approach for IRIS or related inflammatory syndromes.     

The temporal pattern of immune and inflammatory proteins prior to a recurrent coronary event in post-acute coronary syndrome patients

Purpose: We assessed the temporal pattern of 29 immune and inflammatory proteins in post-acute coronary syndrome (ACS) patients, prior to the development of recurrent ACS.

Methods: High-frequency blood sampling was performed in 844 patients admitted for ACS during one-year follow-up. We conducted a case-control study on the 45 patients who experienced reACS (cases) and two matched event-free patients (controls) per case. Olink Proteomics’ immunoassay was used to obtain serum levels of the 29 proteins, expressed in an arbitrary unit on the log2-scale (Normalized Protein eXpression, NPX). Linear mixed-effects models were applied to examine the temporal pattern of the proteins, and to illustrate differences between cases and controls.

Results: Mean age was 66?±?12 years and 80% were men. Cases and controls had similar baseline clinical characteristics. During the first 30 days, and after multiple testing correction, cases had significantly higher serum levels of CXCL1 (difference of 1.00 NPX, p?=?0.002), CD84 (difference of 0.64 NPX, p?=?0.002) and TNFRSF10A (difference of 0.41 NPX, p?<?0.001) than controls. After 30 days, serum levels of all 29 proteins were similar in cases and controls. In particular, no increase was observed prior to reACS.

Conclusions: Among 29 immune and inflammatory proteins, CXCL1, CD84 and TNFRSF10A were associated with early reACS after initial ACS-admission.     

人类免疫缺陷病毒感染者免疫功能重建不全的研究进展

约20%的人类免疫缺陷病毒(human immunodeficiency virus,HIV)感染者在接受抗病毒治疗后,外周血CD4^＋ T细胞水平无法有效恢复,即免疫功能重建不全,但发生机制目前尚不明确。本文根据HIV感染者的临床和免疫学指标,分析发生免疫功能重建不全的风险因素;进一步从外周循环系统中T细胞损伤、细胞因子变化及肠道黏膜局部CD4^＋ T细胞删除等方面解析可能机制,其中肠道黏膜CD4^＋ T细胞删除可能与肠道微生物菌群诱导的细胞焦亡有关。虽然目前国际上有多项关于免疫功能重建不全患者治疗方案的临床试验,但由于缺乏一致的、有力的基础研究证据,导致疾病诊断指标缺乏,单独细胞因子给药治疗亦未取得突破性进展。因此,应深入探索免疫功能重建不全发生机制,进行大样本、长时间的前瞻性队列研究,制定免疫功能重建不全的临床与免疫学界定标准,从而为临床治疗提供科学依据。