Lewis (Le) blood group system phenotypes and genotypes

The Lewis blood group system in humans, designated with number 007 and symbol Le, consist of two different fucose containing carbohydrate antigen structures abbreviated Le^a+ (LE-1) and Le^b+ (LE-2). The expression of these two carbohydrate sequences are phenotype determinants. The Le^a+ antigen sequence is triasaccharide β-D-Galp-(1- 3)-[α-L-Fucp-(1-4)]-D-GlcpNAc. The Le^b+ antigen sequence is tetrasaccharide α-L-Fucp-(1-2)-β-D-Galp-(1-3)- [α-L-Fucp-(1-4)]-D-GlcNpAc. Biosynthesis of Le blood group glycan antigens is catalyzed by fucosyltransferase 2 (FUT2) and fucosyltransferase 3 (FUT3) enzymes. These enzymes are encoded by two dominant autosomal genes named FUT2, also referred as secretory (Se) gene, and FUT3, both having multiple alleles. These two genes determine Lewis blood group genotypes. Sequencing of fucosyltransferase genes, RNAs and fucosyltransferase enzymes and the determination of their structures, together with functional studies including spatial and temporal expression patterns, showed preservation of the catalytic domain within prokaryotes and eukaryotes, with a high level of diversity in structural and functional properties. Six different Le blood group phenotypes exist, taking in account that Le and ABO blood group antigens both comprise terminal sequences on the same branched glycan molecules: Le^a+b-, Le^a-b+, Le^a-b-, Le^a+b+, ALe^a-b+, and BLe^a-b+. Le antigens are part of glycan structures synthetized in glycolipids or glycoprotein form in the endoderm and not in the erythrocyte precursor cell. They are present on the cell surface of blood cells, in plasma and in secretory fluids. Le glycolipids are adsorbed from plasma on the cell surface of erythrocytes, platelets, lymphocytes and endothelial cells.     

Genetic relationships between the HL-A system, the blood group systems (Rh, ABO) and the immune reactivity]

The authors examined in immunized healthy persons the correlations between the ability of immune response, the value of their different immunological parameters, and the HL-A blood-group antigens by computer analysis. Immune reactivity showed mosaic-like correlation against the HL-A system. The most definite negative correlation was noticed between the HL-A 3 and 7 antigens and the cytotoxic activity of lymphocytes. Remarkable and definite correlation was found between the Rh system and immune reactivity. The level of the natural antibodies, the immunoglobulins and the functions of lymphocytes were generally decreased in males in comparison to females.     

Association of the M blood group system with bovine mastitis

Associations of the 11 bovine blood group systems with mastitis were examined in Red Danish dairy cattle. The mastitis status was followed during three lactational periods. A significant effect of the M blood group system on mastitis incidence was observed in the first and second lactation periods and a lower frequency of mastitis is found among animals lacking the M' factor as compared to those having the M' blood group factor. The significance of these results are discussed in view of the close relation between the M blood group system and the bovine lymphocyte antigens (BoLA), and the expected effect of eliminating the M' gene from the breed is estimated. Among the remaining 10 blood group systems, the T' system was the only system showing an overall effect on mastitis, and only in first and third lactation. However, the T' system was inconsistent with regard to the effect of the T' gene on the various mastitis diagnoses.     

Mm, a new factor in the porcine M blood group system

By means of a new antiserum, Mm, the Mae phenotype can be shown to be controlled by the Maem allele, the Mef phenotype by either the original Mef or a new Mefm allele, and the Mbe(f) phenotype by the Mbe(f)m allele. The complexity of the porcine M system is now extended to 13 internationally recognized blood group factors controlled by at least 19 alleles.     

On the possibility of the MN blood group determination in human bones

After a series of preliminary tests on inert substances and on saliva drawn from donors of know MN blood group, 31 right femura from Pisa cemetery buried for 25–30 years and 37 eneolithic femura from Gaudo necropolis near Paestum (2500 – 2000 B.C.) were submitted to 140 assays for the MN system using the standard technique already devised in our Laboratory for ABO blood group determination.Positive and reproducible results were obtained in 18:31 recent femura (58%) and in 24:37 eneolithic bones (65%). The following phenotype and gene frequencies were obtained:

$\text{recent femura:}\text{8.}\text{M}\text{+3.}\text{N}\text{+7.}\text{MN}\text{=18; 0·64m+0.·36n=1}$

$\text{eneolithic femura:}\text{9.}\text{M}\text{+6.}\text{N}\text{+9.}\text{MN}\text{=24; 0·56m+0·44n=1}$

When the ABO and the MN blood group determinations are performed in parallel, a significant positive connection between the two diagnosabilities is observable: P = 0·0387 in the case of the eneolithic bones, $\text{P ? 0·02}$ in the case of the total sample of 59 eneolithic and recent bones tested in parallel. This fact could be reasonably explained considering the similarity of the chemical structure of MN and ABO glycoproteins, which would account for a similar behaviour in preservation.The absence or the very low concentration of M and N substances in tissues and body fluids would on the other hand agree with the percentage of diagnosability: lower in the MN system (60–65%) than in the ABO system (75–80%). The more problematical character of MN blood group typing of bones could be better approached if further research were done.     

Association of the M blood group system with bovine mastitis*

Associations of the 11 bovine blood group systems with mastitis were examined in Red Danish dairy cattle. The mastitis status was followed during three lactational periods. A significant effect of the M blood group system on mastitis incidence was observed in the first and second lactation periods and a lower frequency of mastitis is found among animals lacking the M' factor as compared to those having the M' blood group factor. The significance of these results are discussed in view of the close relation between the M blood group system and the bovine lymphocyte antigens (BoLA), and the expected effect of eliminating the M' gene from the breed is estimated. Among the remaining 10 blood group systems, the T' system was the only system showing an overall effect on mastitis, and only in first and third lactation. However, the T' system was inconsistent with regard to the effect of the T' gene on the various mastitis diagnoses.     

Lm, a new blood group factor of the L system in pigs

A new blood group factor was found and designated Lm. Its genetic classification widens the so far known allele L^agi to L^agim.     

血液培养联合血液微生物抗体检测在社区获得性 肺炎住院儿童诊断中的应用分析

目的研究血液培养联合血液微生物抗体检测在社区获得性肺炎住院儿童诊断中的应用。方法选择2017年1月-2017年12月在本院儿科治疗的确诊为社区获得性肺炎(community-acquired pneumonia,CAP)的患儿298例。采用自行设计的调查表研究患者基本资料,血液培养联合血液微生物抗体检测患儿血液中致病微生物分布情况。结果 200例CAP患儿检出阳性结果,其中呼吸道微生物IgM抗体检测阳性145例,血培养细菌检测阳性55例。呼吸道微生物IgM抗体检测阳性结果中,支原体(19.46%)是最常见的病原体,其次为乙型流感病毒(16.44%),再次是副流感病毒(6.38%)、腺病毒(5.70%)、甲型流感病毒(0.67%),未检出衣原体。血培养阳性结果中,流感嗜血杆菌(5.36%)是最常见的病原体,其次为肺炎链球菌(5.03%),再次是克雷伯杆菌(3.02%)、大肠埃希菌(1.68%)、鲍曼不动杆菌(1.01%)。不同年龄组患儿病原微生物检出情况显示29天~1岁患儿支原体、乙型流感病毒、副流感病毒、腺病毒检出率明显大于1~3岁、4~6岁、7~14岁患儿,1~3岁患儿支原体、乙型流感病毒检出率明显大于4~6岁、7~14岁患儿。结论本地区CAP患儿的最常见病原体是支原体,检出率为19.46%,而且病毒和支原体感染率呈现低龄化趋势。