Immunoglobulin a (Iga) Levels in Healthy Blood Donors in Yaounde, Cameroon (original) (raw)
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An evaluation of the DiaMed assays for immunoglobulin A antibodies (anti-IgA) and IgA deficiency
Transfusion, 2008
BACKGROUND: Immunoglobulin A antibodies (anti-IgA) are rare but can cause transfusion-associated anaphylaxis. The detection of anti-IgA has traditionally been performed using a labor-intensive hemagglutination assay in a limited number of reference laboratories.STUDY DESIGN AND METHODS: Two simple gel card assays are now available that can be used to screen for anti-IgA and IgA deficiency. A total of 24 serum samples that had been previously assayed for anti-IgA over a 3-year period were used to assess the DiaMed anti-IgA and IgA deficiency assays.RESULTS: The DiaMed assays correctly identified patients (n = 6) who had significant IgA deficiency and anti-IgA. All patients with an abnormal anti-IgA titer by hemagglutination assay and who were also IgA-deficient had anti-IgA detected using the DiaMed screening test. One patient, previously shown to have an IgA level of less than 0.067 g per L, failed to be detected as IgA-deficient in the DiaMed IgA deficiency test; however, anti-IgA were not present. Samples with slightly increased anti-IgA titers tended to have normal IgA levels.CONCLUSION: The DiaMed gel card screening assays are appropriate screening tools for the investigation of transfusion-related anaphylactic reactions and can be used in any routine blood bank laboratory.
Vox Sanguinis, 2010
Background and Objectives IgA deficiency is common (1 ⁄ 500) and up to 40% of affected individuals will develop anti-IgA. A few studies suggested that passive transfusion of anti-IgA was not associated with an increased risk of allergic reactions. This study was designed to assess the safety of transfusing blood components containing anti-IgA. Materials and Methods IgA-deficient blood donors with and without anti-IgA were identified from Héma-Québec's (HQ) computerized database. IgA deficiency was confirmed by an ELISA method and the presence of anti-IgA by a passive hemagglutination assay. Blood donations from IgA-deficient donors issued to hospitals between March 1999 and December 2004 were retrieved. Medical charts of recipients were reviewed for the occurrence of a suspected transfusion reaction. Presence and nature of transfusion reactions were assessed blindly by an adjudicating committee. Results A total of 323 IgA-deficient blood products were issued by HQ to 55 hospitals. Of these, 48 agreed to participate [315 blood products (97AE5%)]. A total of 272 products were transfused: 174 contained anti-IgA, and 98 did not. Only two minor allergic reactions occurred in each group. Incidence of allergic reactions was 1AE15% in the anti-IgA group and 2AE04% in the group without anti-IgA (P = 0AE91). There was no anaphylactic reaction in either group. Conclusions This study indicates that the proportion of allergic reactions does not appear to be greater in recipients of blood components containing anti-IgA compared to recipients of non-anti-IgA-containing components. Allowing donations from IgA-deficient donors with anti-IgA may therefore be contemplated.
Benefits and risks of IgA in immunoglobulin preparations
Transfusion and Apheresis Science, 2012
The case of Immunoglobulin A (IgA) in transfusion medicine is unsettled: on one hand IgA is an important component of adaptive immunity and its deficiency may cause disease, on the other its presence in blood products might induce, in rare instances, allergy-like symptoms if not anaphylaxis.
Low prevalence of IgA deficiency in north Indian population
Background & objectives: IgA deficient patients are at risk of severe anaphylactic reaction on being transfused blood and blood products, and its prevalence varies in different parts of the world. No data are available from India.We did a blood donor survey to look for prevalence of IgA deficiency in north India.
Iranian journal of allergy, asthma, and immunology, 2008
Selective deficiency of immunoglobulin A (IgA) is the most frequent primary hypogammaglobulinemia. As some IgA-deficient patients have IgA antibodies in their plasma which may cause anaphylactic reactions, blood centers usually maintain a list of IgA-deficient blood donors to prepare compatible blood components. In this study we determined the incidence of selective IgA deficiency (SIgAD) in normal adult Iranian population. 13022 normal Iranian blood donors were included in this study. The assay which we used was adapted to the manual pipetting system and ELISA reader was used for screening. Other classes of immunoglobulins (G, M), as well as secretory IgA and IgG subclasses were tested in IgA deficient cases by ELISA. SPSS was used for statistical analysis.Among 13022 studied cases, 11608 blood donors were males (89.14%) and 1414 were females (10.86%). Their mean (+/-SD) age and weight were 38.5+/-11 years and 82+/-12 Kg respectively. Twenty of the screened samples were found by me...
A new strategy for the prevention of IgA anaphylactic transfusion reactions
Transfusion, 2004
Management of patients with clinically significant anti-IgA is difficult and unsatisfactory in many aspects. A 40-year-old man with common variable immunodeficiency had a previous history of anaphylaxis after an intramuscular immunoglobulin administration. His serum contained anti-IgA, and he required immunoglobulins for recurrent infections. The administration of intravenous immunoglobulins (IVIgG) containing less than 0.1 mg per mL IgA led to an anaphylactic reaction after the transfusion of only 2 to 3 mL. The same IVIgG charge was subsequently pretreated with freshly separated autologous plasma and given to the patient on three consecutive days without any reaction (1.25, 10, and 10 g each in 400 mL plasma). Anti-IgA activity did not increase, and the patient was treated again without complications. Ex vivo pretreatment of IVIgG preparations with autologous plasma appears to be safe and useful in the management of patients with clinically significant anti-IgA. To achieve a significant IgA blockage, the preparation to be used should not contain large amounts of IgA. The strategy described here appears to be safe and may help prevent anaphylaxis in many instances.
Vox Sanguinis, 1971
The case history and investigations of a 32-year-old man with pernicious anaemia and selective absence of IgA in serum and saliva are presented and discussed. On two occasions, the patient, who had not previously been exposed to foreign human serum, developed severe anaphylactic shock after blood transfusion of a few millilitres. A precipitating antibody to IgA was identified in his serum. It was of class-specific type reacting not only with the donors' sera, but also with other normal sera. The patient had no apparent chromosome abnormality, and no close family members had similar IgA lack. Lymphocyte transformation in vitro with PHA was normal: no stimulation followed exposure t o IgA. On fluorescent microscopy, very few IgA-containing cells were seen in the gastric mucosa.
Transfusion, 2012
BACKGROUND: Immunoglobulin A (IgA)-deficient patients with anti-IgA (Ab) require transfusions using blood components with less than 0.05 mg IgA/dL as they are known to be safe for these patients. Identification of severely IgA-deficient (IgA SD) donors involved preliminary screening by the Ouchterlony double immunodiffusion assay followed by confirmatory testing at the required level of sensitivity for IgA and Ab at an external reference laboratory. Two in vitro particle gel immunoassays (ID-PaGIA IgA deficiency test and anti-IgA test) were also evaluated for their suitability in identifying IgA SD individuals and determining their Ab status. STUDY DESIGN AND METHODS: Samples from 198 donors and 36 patients, subjected to confirmatory testing for IgA SD and Ab over a 2-year period, were also evaluated using the ID-PaGIA kits. RESULTS: DiaMed test sensitivity and specificity for detection of IgA SD in donors was 98% whereas for Ab, test sensitivity was 91% at a specificity of 94%. In patients, sensitivity was 94% for IgA SD and 67% for Ab, both tests at a specificity of 100%. CONCLUSIONS: The ID-PaGIA IgA deficiency test was a sensitive and specific tool for identifying IgA SD donors or patients. Sensitivity of the Ab test was high for donors but reduced for patients and of high specificity in both groups. Further studies with patients are needed to confirm this latter observation. Implementation of these tests would make it possible to supply appropriate products from IgA SD donors to prevent anaphylactic transfusion reactions in patients.
Transfusion, 2008
To avoid anaphylactic reactions, immunoglobulin (Ig)A-deficient patients with anti-IgA should be transfused with IgA-deficient blood components. There is a need for fast and robust assays for demonstration of IgA deficiency and for detection of anti-IgA. STUDY DESIGN AND METHODS: Recombinant human IgA1 and IgA2 anti-D molecules were constructed, expressed in Chinese hamster ovary cells, and purified. These antibodies were used to sensitize group O D+ red blood cells (RBCs) for use as indicator cells, either in the format of a passive hemagglutination inhibition assay for detection of IgA deficiency or in a passive hemagglutination assay for detection of anti-IgA. Both assays were performed in gel card. RESULTS: The sensitivity for IgA detection was adjusted to approximately 100 ng per mL. The assay for demonstration of IgA deficiency correlated with an enzyme-linked immunosorbent assay for quantification of IgA. Anti-IgA were easily detected, and the reactivity with IgA anti-D-sensitized RBCs could be inhibited by purified IgA1 and/or IgA2 and by normal plasma containing IgA but not by IgA-deficient plasma. Anti-IgA was found in 64 percent of IgA-deficient donors with less than 3 ng of IgA per mL. CONCLUSION: The assays for detection of IgA and anti-IgA described in this article are fast and robust. Furthermore, they are applicable in all standard blood typing laboratories and are therefore well suited for immediate investigation of transfusion reactions. ABBREVIATIONS: rIgA1 = recombinant human immunoglobulin A1 anti-D; rIgA2 = recombinant human immunoglobulin A2m(1) anti-D; rIgG1 = recombinant human immunoglobulin G1 anti-D; rIgG3 = recombinant human immunoglobulin G3