Selective deficiency of immunoglobulin A among healthy voluntary blood donors in Iran.

摘要: Dear Sir, immunoglobulin A (IgA) was first identified in serum about 50 years ago and is the second most abundant immunoglobulin after IgG. Shortly afterwards, IgA found to be main secretions. Although secretory has many known functions, role of remains unclear. Serum deficiency described children with ataxia-telangiectasia, but later other patients populations normal subjects. The prevalence reported blood donors ranges from 1:400 1:3000 Western countries; lower some Asian countries1. Most affected persons are asymptomatic, IgA-deficient subjects suffer recurrent sino-pulmonary infections, autoimmunity or allergies. can transient children, adults usually permanent 1,2. Since its establishment, 42 cases selective deficiency, mainly Iranian have been National Registry Primary Immunodeficiency3; present study designed obtain an insight into healthy donors, issue which not previously studied. In general, knowledge this immunodeficiency Middle Eastern countries rather poor. Since Iran a multi-ethnic country, areas fairly homogenous genetic background, studied various different regions, as well Tehran, capital city. For purpose samples were taken volunteer four regional centres Blood Transfusion Organisation routine physical examination completion required questionnaire consent form. centre, where 3250 collected, Tehran used example urban city representative general population. centre selected, Bandare Turkman, north-east Iran; majority population here Turkman origin 900 collected. third Kermanshah, west consisting Kurds; 3622 collected centre. Finally, 1080 Bushehr south Iran, ages ranged 18–63 years. Another group, 95 degree family members deficient individuals, also studied. In order compare determined among groups, chi-square test Fisher’s exact used. Differences considered statistically significant at p values <0.05. Immunoglobulins estimated using commercial immunodiffusion plates, Nor-Partigen Behring (Marburg, Germany). screening carried out standard plates detection limit 5 mg/dL. Subjects whose (less than mg/dL) rechecked sample 3–6 months; these cases, “low concentration” same company, level less 1 mg/dL used. checked for levels IgG IgM specific (Behring, Marburg, Germany). The results obtained 8852 summarised table I, clearly shows that significantly between geographical regions. This detected 1:450 Bandar being higher three regions studied. Table I IgA Regional Iran Repeating assay on months confirmed persistence adult individuals. The nine individuals tested levels; within range all no concomitant observed. Finally, incidence first-degree relatives immunodeficient 5%, times unrelated subjects. An important factor when considering frequency definition which, study, classical <5 However, we had 1mg/dl. In overall 1.02/1000. figure close Europe North America; unfortunately there reports comparison. data presented may indication rate part world probably 1. The difference observed possible background probable consanguinity. city, demonstrates open ethnically mixed more stable, rural genetically homogeneous populations, probability consanguinity higher. Similar differences monoclonal gammopathy French populations. The southern region seems very low further larger required. IgA appears inherited sporadically, although familial inheritance autosomal recessive dominant fashion variable incomplete expression described. Ethnic variability recognised, frequencies Caucasians oriental studied1,2; showing geographic evidence variation. When (95 cases) studied, additional discovered five families. remaining families, 7.3% (38-fold increase) previous studies. As far molecular genetics concerned, association translocations chromosome reported. The immune defect interfered life. major immunoglobulins (IgG IgM) limits histories revealed infections those without deficiency. Finally, it should noted concern transfusion services since exposed products containing develop anti-IgA antibodies cause anaphylactic reactions1. Despite yielding definitive diagnosis fewer 20% reactions, investigation presence presumably pathogenic useful patient management. Individuals demonstrated must receive IgA-depleted cellular plasma derivatives prevent severe reactions 4. fatal reaction due anti-IgA, occurring 45 min administration mL blood, reported; passive transfer through does not, however, appear greater reactions. The scarcity banked dedicated plateletpheresies led American Association Banks policies allocate such precious resources appropriately5. Developing similar average strongly recommended.