Screening of IgG anti-IgA antibodies in hypogammaglobulinemic subjects with specific readily available IgG anti-IgA ELISA test may prevent anaphylactoid reactions

date: 6. 1. 2010, author: Vojtech Thon, M.D., Ph.D.
Name Anti-IgA isotype IgG Human ELISA
Cat. No. RD199145100R IVD CERD199145100R RUO
Product category Autoimmunity, Immune Response, Infection and Inflammation, Immunology, Transplantation
Assay format Sandwich ELISA, Biotin-labelled antibody
Calibration range 1.56-100 U/ml
Limit of detection 0.71 U/ml
Applications Plasma, Serum
Sample requirements 5 μl/well
Storage/Shipping Store the complete kit at 2-8°C. Under these conditions, the kit is stable until the expiration date (see label on the box).

Anti-IgA antibodies can cause severe anaphylactoid reaction in the case of blood transfusion or substitution immunoglobulin therapy in patients with hypogammaglobu­linemia. We found a significant amount of anti-IgA antibodies in 10 % of patients with the most common primary hypogammaglobu­linemia (selective IgA deficiency and Common variable immunodeficiencies) where the serum IgA level was lower than 0.05 g/l. Knowledge of the presence of antibodies against IgA is important in clinical practice in order to prevent an anaphylactic reaction during the application of a blood transfusion or therapy with immunoglobulin substitution.

by Dr. V. Thon

The occurence of antibodies against IgA in sera of patients with selective IgA deficiency (IgAD) was first described by Fudenberg et al in 1968 [1]. The presence of these antibodies is connected with higher risk of severe anaphylactoid reaction after treatment with blood transfusion or substitution gammaglobulin therapy containing IgA. The first description of anaphylactoid reaction associated with anti-IgA was published by the same group in 1968 [2]. During the following decades the results were confirmed, e.g. in the Scandinavian population by the studies from Finland and Sweden [3, 4]. The incidence of anti-IgA antibodies in persons with IgA deficiency has been reported to vary from 9.6% to 44% [5, 6]. Recently, in a blinded study we analyzed severe adverse reactions and investigated anti-IgA antibodies in a German population of patients after intravenous immunoglobulin infusions (IVIG) and found anaphylactoid reactions specifically in subjects with a high level of IgG anti-IgA antibodies [7]. Anaphylactoid reactions are mediated by activation of complement with generation of vasoactive anaphylatoxines such as C3a, C4a and C5a. The clinical picture is characterized by urticaria, hypotension, and respiratory distress with bronchospasm or stridor [7].

Primary immunodeficiencies are hereditary disorders characterised by the mutation(s) of genes coding some molecules or receptors important for normal function of the immune system. According to the first National Database of Primary Immunodeficiencies established in Europe in the Czech Republic in 1993 the prevalence of primary immunodeficiencies (PID) studied in the Czech Republic is 5.8/100 000 inhabitants. Figure 1 clearly shows that among cases of PID, antibody deficiencies are predominant. Similar results were reported from a more recent European ESID database of primary immunodeficien­cies [8].

Selective IgA deficiency (IgAD) is the most common primary immunodeficiency. This disease is characterised by low serum levels of IgA. Both genetic and environmental factors contribute to the pathogenesis of this disorder. Nevertheless, some individuals with IgAD may be clinically healthy, while others are susceptible to respiratory and gastrointestinal infections, allergy, autoimmune diseases, and malignancy. The occurrence of IgAD is fairly high. For example the prevalence a clinically healthy Czec population of blood donors is 1:408 [9]. This is in accordance with other published data from European and North American countries as well as a recent report of screened Canadian Blood Services donors [10]. Genetically, IgAD seems to be connected with autoimmunity disorders (Hammarstrom, personal communication).

Common variable immunodeficiency (CVID) is another primary immunodeficiency. It is a heterogeneous group of diseases characterized by impaired antibody production of all major Ig classes, which predispose patients to frequent infections of the respiratory tract with encapsulated bacteria. However, the number of B-lymphocytes in peripheral blood is usually normal and in most patients the T cell help for B cells is impaired [11]. As in IgAD both males and females are affected equally. IgAD can develop into CVID. For treatment, substitution immunoglobulin therapy is needed [12].

As mentioned above we systematically studied the prevalence of anti-IgA antibodies and related anaphylactoid reactions following immunoglobulin infusions (IVIG) in CVID patients. Serum immunoglobulins were measured by nephelometry and low concentrations of IgA were confirmed by sensitive ELISA. Cell analysis was performed by flow cytometry [7, 13]. New modifications of the ELISA method were used for sensitive and specific investigation of anti-IgA antibodies. In the first screening step the occurrence of anti-IgA antibodies of IgG class was examined. In the second step the specificity of detection of anti-IgA antibodies was confirmed by the inhibition test and the amount of anti-IgA antibodies was quantified. In one study we investigated 279 patients from the Czech Republic and Germany with common variable immunodeficiency (CVID, n = 131) and IgA deficiency (n = 148). Patients were characterised with ESID/PAGID and EURO-PADnet diagnostic criteria. We found that 10% of hypogammaglobu­linemic patients in central Europe were positive for anti-IgA antibodies [13]. Specific anti-IgA antibodies occur only in patients with undetectable IgA serum level (IgA lower than 0.05 g/l). From the German cohort of CVID patients (n = 88) we identified eight patients with anti-IgA antibodies (titer 1:100 – 1:6400). All lacked IgA+ B cells in peripheral blood. Five of them had a history of severe anaphylactoid reaction to IVIG (anti-IgA antibody titer 1:400 – 1:6400). Moreover, four of these five patients tolerated subcutaneous immunoglobulin substitution (SCIG) [7].

A positive finding of anti-IgA antibodies anables better recogniting and management true cases of anti-IgA anaphylactoid reactions and risk for the blood transfusion services. Anti-IgA mediated anaphylactoid reaction can be prevented by auto transfusion (if this procedure is possible) or by using blood from donors completely lacking IgA, or by thoroughly washing the blood cells to remove donor’s IgA. Therefore positive as well as negative results from screening test for anti-IgA antibodies in IgAD and CVID subjects with serum IgA below 0.05 g/l provides tremendous information and guidance for blood transfusion service [7, 14, 15, 16].

Conclusion

The occurrence of anti-IgA antibodies in high titer is a risk factor associated with anaphylactoid reaction in hypogammaglobu­linemic patients. Presence or absence of anti-IgA antibodies was also considered important basic information (red fields) in the European ESID database of primary immunodeficiencies. Screening for anti-IgA antibodies in patients lacking IgA may be helpful for determing the best therapeutic strategy, including route of substitution immunoglobulin therapy and transfusion of IgA free blood products. From a haematological point of view tested IgA-deficient blood components without anti-IgA antibodies are a precious resource that should be allocated with care and reserved for IgAD patients at risk for anaphylactoid reaction [14]. The combined use of quantitative ELISA for detection of anti-IgA antibodies and the measuring of serum IgA concentration by nephelometry provides an effective and safe strategy for the diagnosis and prevention of IgA anaphylactic transfusion reactions.

References

1. Fudenberg HH et al. Human Antibodies to Human IgA Globulins. Immunochemistry. 1968;5:203–6.
2. Vyas GN, Perkins HA, Fudenberg HH. Anaphylactoid Transfusion Reactions Associated with Anti-IgA. Lancet 1968;2:312–5.
3. Koskinen S, Tolo H, Hirvonen M, Koistinen J. Long-term Follow-Up of Anti-IgA Antibodies in Healthy IgA-Deficient Adults. J Clin Immunol. 1995;15:194–8.
4. Sundin U, Nava S, Hammarstrom L. Induction of unresponsiveness against IgA in IgA-deficient patients on subcutaneous immunoglobulin infusion therapy. Clin Exp Immunol. 1998;112:341–6.
5. Koistinen J, Sarna S. Immunological abnormalities in the sera of IgA-deficient blood donors. Vox Sang. 1975;29(3):203–13.
6. Nadorp JH et al. The significance of the presence of anti-IgA antibodies in individuals with an IgA deficiency. Eur J Clin Invest. 1973;3(4):317–23.
7. Horn J et al. Anti-IgA antibodies in common variable immunodeficiency (CVID): diagnostic workup and therapeutic strategy. Clin Immunol. 2007;122(2):156–62.
8. Gathmann B, et al. The European internet-based patient and research database for primary immunodeficiencies: results 2006–2008. Clin Exp Immunol. 2009 Sep;157 Suppl 1:3–11.
9. Litzman J et al. IgA deficiency in Czech healthy individuals and selected patient groups. Int Arch Allergy Immunol. 2000;123:177–80.
10. Palmer DS, et al. Screening of Canadian Blood Services donors for severe immunoglobulin A deficiency. Transfusion. 2010 Feb 11. [Epub ahead of print]
11. Thon V et al. Defective integration of activating signals derived from the T cell receptor (TCR) and costimulatory molecules in both CD4+ and CD8+ T lymphocytes of common variable immunodeficiency (CVID) patients. Clin Exp Immunol. 1997;110:174–81.
12. Chapel H et al. Common variable immunodeficiency disorders: division into distinct clinical phenotypes. Blood. 2008;112(2):277–86.
13. Thon V et al. The prevalence of anti-IgA antibodies in central Europe and relation to anaphylactoid reactions in patients with hypogammaglobu­linemia. Annual meeting of the Austrian Society for Allergology and Immunology. Abstract book 2007:MI7.
14. Yuan S, Goldfinger D. A readily available assay for anti-immunoglobulin A: is this what we have been waiting for? Transfusion. 2008;48(10):2048–50.
15. Bjorkander J et al. Immunoglobulin prophylaxis in patients with antibody deficiency syndromes and anti-IgA antibodies. J Clin Immunol. 1987;7:8–15.
16. Sandler SG et al. IgA anaphylactic Transfusion Reactions. Transfus Med Rev. 1995;9:1–8.

The author

Vojtech Thon, M.D., Ph.D.
University Centre for Primary Immunodeficiencies
Department of Clinical Immunology and Allergology
St. Anne University Hospital, Masaryk University
Pekarska 53, CZ-656 91 Brno
The Czech Republic
Tel. +420–54318 3128
Fax: +420–54318 3143
E-mail: vojtech.thon@fnusa.cz



Fig. 1: Predominance of antibody deficiencies – The Czech National Database of Primary Immunodeficiencies

Catalog NumberSpeciesAnalyteAssayRegulatoryFormat
RD199145100R Human Anti-IgA IgG Sandwich ELISA, HRP-labelled antibody IVD CE 96 wells (1 kit)
categories: Autoimmunity, Immune Response, Infection and Inflammation, Immunology, Transplantation