Study on immunoglobulin A Deficiency(IgAD) in Chinese Shanghai Blood Donors / 中国实验血液学杂志

<p><b>UNLABELLED</b>Objective：To calculate the prevalence of IgAD in a replicate cohort of the Chinese Han population in Shanghai area by screening blood donors and to study the genetic difference of IgAD individuals in the Mongoloid population.</p><p><b>METHODS</b>The prevalence of IgAD in a large number of Chinese blood donors (n=61624) in Shanghai area was investigated. The immunoglobulin class, IgG subclass and anti-IgA serum levels were measured among the IgAD donors. These donors were subsequently tissue typed and the allele frequency was compared with the Shanghai bone marrow donor HLA registry.</p><p><b>RESULTS</b>Thirty-one IgAD blood donors were identified, giving a prevalence of 1:2000(31/61624). Most IgAD donors had serum IgG levels above the normal range with no major IgG subclass deficiency and 3 donors was positive for anti-IgA. Two-thirds of the IgAD donors carried Caucasian IgAD associated risk haplotypes, including DRB1*0301-DQB1*0201, DRB1*0701-DQB1*020 and DRB1*0102-DQB1*0501, giving a significantly higher frequency of these haplotypes as compared to the Shanghai bone marrow donor HLA registry.</p><p><b>CONCLUSION</b>The prevalence of IgAD in Chinese Han population is markedly lower than that in Caucasians. The low prevalence of IgAD can potentially be due to the low frequency of the disease associated risk haplotypes in China. However, potential risks exist in performing blood transfusion to IgAD persons, and measures should be taken to reduce IgA anaphylaxis. Meanwhile, it is necessary to set up a Shanghai rare blood bank of IgAD donor for patients to meet the needs of IgA-poor transfusion.</p>

Construction of a high efficiency PCR products cloning T vector using pGEM-5zf[+]

A highly efficient cloning vector was constructed for cloning PCR products by inserting an 80 bp DMA fragment into pCEM-5zf [+] vector. The Xcm I digestion of this vector gave rise to a 3 overhanging deoxythymidine offering the possibility of cloning PCR products with 3' adenosine overhang created by Taq DMA polymerase. Furthermore, two EcoR I sites were added to the construct for identification of recombinant plasmids using a single restriction enzyme. Taken together, the more efficient cloning performance and the lower cost of this vector as compared to the commercial T vector, suggests that it may be one of the best T vectors for cloning of PCR products

Onychomadesis in a patient with immunoglobulin class switch recombination deficiency

Immunoglobulin class switch recombination deficiencies [Ig CSR deficiencies] or Hyper IgM syndromes [HIGM] are a group of primary immunodeficiency diseases, characterized by defective CD40 signaling of B cells resulting into a CSR and a somatic hypermutation. The affected patients are characterized with reduced serum levels of IgG and IgA, and normal or elevated level of IgM, which lead to increased susceptibility to infections. We describe a 3 year-old boy with frequent bacterial infections of the skin and respiratory tract, mucosal ulcers, and diarrhea. He experienced onychomadesis in both fingernails and toenails during recent bacterial infection. Quantitative immunoglobulin levels revealed high levels of serum IgM and very low levels of IgG, IgA, and IgE. Clinical and immunologic studies supported the diagnosis of HIGM. Onychomadesis as a finding in HIGM could be considered. Considering exclusion of CD40L, CD40, AID and UNG genes by molecular analysis, new CSR selective deficiencies could be suspected in this case

Human leukocyte antigens [HLA] associated with selective IgA deficiency in Iran and Sweden

Selective IgA deficiency [IgAD] [serum IgA concentration of <0.07 g/l] is the most common primary immunodeficiency in Caucasians, with an estimated prevalence of 1/600. There are strong indications for involvement of genetic factors in development of the disease and the frequency of several extended major histocompatibility complex haplotypes [including HLA-A1, B8, DR3, DQ2] have previously been shown to be increased among Caucasian patients with IgAD. PCR was used to type HLA B, DR, and DQ alleles in 29 Iranian individuals with IgAD and 299 Swedish individuals with IgAD. The results indicate a strong association with the HLA B14, DR1 alleles in Iranian subjects and HLA B8, B12, B13, B14, B40, DR1, DR3, DR7, DQ2 and DQ5 alleles in Swedish subjects. Differences in HLA association of IgAD in Iran and Sweden confirm the notion of a genetic background of the disease and that multiple, potentially different genes within the MHC region might be involved in the pathogenesis of IgAD in different ethnic groups