Serum Protein Electrophoresis May Be Used as a Screening Tool for Antibody Deficiency in Children and Adolescents.

Background: Patients with antibody deficiency may experience exceptionally long diagnostic delays, increasing the risk of life-threatening infections, end-organ damage, mortality, and health costs. Objective: This study aimed to analyze serum protein electrophoresis and verify the correlation between calculated globulin (CG, total protein minus albumin levels) or electrophoretically determined serum gamma globulin fraction (Gamma) with IgG levels in children and adolescents under 18 years old (yo). Methods: We analyzed serum protein electrophoresis (GC or Gamma) and IgG levels from 1215 children and adolescents under 18 yo, classified into 5 age groups. We verified the correlation between CG or Gamma with serum IgG levels. Results: Serum IgG levels varied according to age groups (from 4.3 ± 2.3 g/l in children under 6 months old to 11.4 ± 3.2 g/l in adolescents in the 10-<18 yo group). CG sensitivity and specificity to detect IgG below the reference range for all patients were 93.1% and 81.8%, respectively, and varied according to age group. Gamma sensitivity and specificity for all patients were 100% and 87.8%, respectively, and varied according to age group as well. We found serum IgG levels below the age reference level in 29 patients (2.4% of the cases) using CG or Gamma levels. Conclusion: Both CG and Gamma levels may be of utility as a screening tool for earlier diagnosis of antibody deficiency in children and adolescents under 18 yo.

The Utility of IgA-Based Serologic Markers in Diagnosing Celiac Disease in Children 24 Months of Age or Younger.

Current screening guidelines in North America for celiac disease recommend additional IgG based testing for younger children. Our multicenter retrospective study showed that the anti-tissue transglutaminase IgA antibody test should be the recommended initial test in all children, including those ≤24 months of age.

Niveles de IgA en adultos con enfermedad celíaca / IgA levels in adults with celiac disease

La enfermedad celíaca (EC) es una enfermedad autoinmune sistémica desencadenada por el consumo de gluten de la dieta en personas con susceptibilidad genética. Los principales test serológicos utilizados para el diagnóstico y seguimiento de la EC son pruebas basadas en anticuerpos de isotipo inmunoglobulina (Ig) A, siendo la determinación de IgA anti-transglutaminasa tisular (tTG)2 la prueba serológica inicial de elección. La deficiencia selectiva de IgA (DSIgA), es más prevalente en pacientes con EC que en la población general, dificultando el diagnostico serológico de la enfermedad. En el presente estudio observacional descriptivo, se incluyeron 74 pacientes adultos con diagnóstico confirmado de EC y se determinó IgA anti-tTG2 en suero mediante ensayo de ELISA a fin de detectar a aquellos pacientes con niveles indeterminados o negativos, los cuales podrían presentar DSIgA. Se dosó IgA total en el suero de estos pacientes por inmunodifusión radial y el promedio fue de 237,8 ± 100,6 mg/dL. En una paciente del sexo femenino fue detectada IgA total menor a 7 mg/dL, con niveles séricos de IgG e IgM normales, característicos de la DSIgA. Así, la frecuencia calculada de DSIgA fue de 1,35% en la población con EC estudiada. En conclusión, este trabajo es una primera aproximación para describir la frecuencia de DSIgA en pacientes con EC del país y reafirma la importancia de incluir el dosaje de IgA total en el caso de realizar test serológicos de la EC basados en IgA(AU)

An acute transfusion reaction.

We present the case of a 67-year-old man who suffered an acute anaphylactic reaction during red cell transfusion due to the presence of anti-IgA antibodies. The incidence and clinical relevance of anti-IgA antibodies in IgA deficiency is reviewed, and the wider investigation and management of acute transfusion reactions is also discussed. This case highlights the need to consider the potential risks of blood component transfusion against the purported benefit.

Oral manifestations of selective IgA-deficiency: review and case-report.

Immunoglobulin A deficiency is the most common primary immunodeficiency defined as decreased serum level of IgA (less than 7 mg/dl) in the presence of normal levels of other immunoglobulin isotypes. Most individuals with IgA deficiency are asymptomatic and identified coincidentally. However, some patients may present with recurrent infections, allergic disorders and autoimmune manifestations, such as diabetes mellitus, Graves disease and celiac disease. The international literature has not produced any kind of review yet about intra-oral manifestations of selective IgA-deficiency. L.S., a 7-year-old Caucasian girl, was examined at our hospital. After she had undergone a professional dental cleaning, a symmetric, bilateral ulcerative gingivitis developed nearby the upper second primary molars. The gingival ulcers were persistent and did not disappear in the following 3 weeks. In the meantime, the young patient reported the presence of gastrointestinal symptoms. IgA serum level was 4.5 mg/dl, while the other isotypes levels were in the common range. The diagnosis of selective IgA-deficiency was formulated and the girl underwent further examination for the specific IgG autoantibodies in celiac disease, which were not present. Consequently, a full prevention program was planned. This case report emphasizes the role of the paediatric dentist in the early detection of systemic disorder, such as the immunological diseases. The oral cavity often reveals to be the first site of manifestation of important systemic diseases. Immunoglobulin A (IgA) deficiency is the most common primary immunodeficiency and is defined as a decrease in serum IgA levels in the presence of normal levels of other immunoglobulin isotypes (1). Serum IgA deficiency was first described in children with ataxia-telangiectasia (2) and has since been identified in other patients, including normal patients. The prevalence of IgA deficiency ranges from 1:223 to 1:1000 in community studies and from 1:400 to 1:3000 in healthy blood donors (3).

Implementation of National Institute for Health and Care Excellence (NICE) guidance to measure immunoglobulin A with all coeliac screens: can an affordable solution be devised?

There has been a dramatic increase in requests for coeliac disease (CD) serological screening using immunoglobulin (Ig)A tissue transglutaminase antibodies (IgA-tTG). Recently, the UK National Institute for Health and Care Excellence has revised its guidance, recommending that total IgA should also be measured in all samples. This is justified, as false-negative results may occur with IgA deficiency. However, implementation of this guidance will incur considerable expense. Tests that measure IgA-tTG antibodies can detect IgA deficiency, indicated by low background signal. This provides an opportunity to identify samples containing IgA ≤ 0·2g/l, obviating the need for unselected IgA measurement. We investigated the feasibility of this approach in two centres that use the EliA™ Celikey™ assay or QUANTA Lite® enzyme-linked immunosorbent assay to quantify IgA-tTG antibodies. In both cases, total IgA correlated strongly with background IgA-tTG assay signal. Using the Celikey™ assay, a threshold of < 17·5 response units achieved 100% sensitivity (95% confidence intervals 79·4-100%) for detection of IgA ≤ 0·2g/l, circumventing the need for IgA testing in > 99% of sera. A similar principle was demonstrated for the QUANTA Lite® assay, whereby a threshold optical density of < 0·0265 also achieved 100% sensitivity (95% confidence intervals 78·2-100%) for IgA ≤ 0·2 g/l, avoiding unnecessary IgA testing in 67% of cases. These data suggest that CD screening tests can identify samples reliably containing low IgA in a real-life setting, obviating the need for blanket testing. However, this approach requires careful individualized validation, given the divergent efficiency with which assays identify samples containing low IgA.

Population-Based Screening for Selective Immunoglobulin A (IgA) Deficiency in Lithuanian Children Using a Rapid Antibody-Based Fingertip Test.

BACKGROUND Selective immunoglobulin A (IgA) deficiency is the most common inherited immunodeficiency disorder worldwide. An early diagnosis is advocated because of the increased risk of infections, autoimmune diseases, and allergic reactions. We investigated the usefulness of a rapid point-of-care test in detecting for IgA deficiency in a population with a previously unknown prevalence. MATERIAL AND METHODS Altogether, 1000 children aged 11-13 years from randomly selected Lithuanian schools were enrolled. A point-of-care test with a fingertip sample was used to screen for the presence of IgA deficiency in children whose parents gave consent. Those with suspected IgA deficiency were referred to hospital for further clinical examination and confirmation of the diagnosis. In addition, their medical histories were compared with those of 30 age- and sex-matched healthy controls. RESULTS IgA deficiency was suspected in one girl and in three boys on the basis of the rapid test, and the diagnosis was confirmed for all four cases (prevalence 0.4%, 95% confidence interval 0.16-1.02%). There was no difference in disease history or complications between IgA-deficient children and healthy controls. CONCLUSIONS The rapid antibody test is a practical and accurate method to diagnose selective IgA deficiency in children. The prevalence of IgA deficiency among Lithuanian schoolchildren is 1:250.

Immunoglobulin A deficiency following treatment with lamotrigine.

Lamotrigine (LTG) is an anti-epileptic drug and mood-stabilizing agent, whose adverse effects include skin rash and dizziness. Interactions with the immune system are rare, and only a few cases linking hypogammaglobulinemia to LTG treatment have been previously described. In this report, we describe a case in which a patient developed hypogammaglobulinemia, and a subsequent immunoglobulin A (IgA) deficiency, following LTG treatment. As a result of her immunodeficiency, the patient presented with a severe urinary tract infection and required intravenous immunoglobulin. Serum levels of immunoglobulin G and M had recovered by seven months and one month after the discontinuation of LTG, respectively; however, IgA levels remained low (less than 4mg/dL) two years post-treatment. While previous reports have demonstrated IgA deficiencies in patients prescribed other antiepileptic drugs, this is the first case of an IgA deficiency following LTG administration.

Prevalence of selective immunoglobulin A deficiency in Greek children and adolescents with type 1 diabetes.

BACKGROUND: The association of selective immunoglobulin A (IgA) deficiency with type 1 diabetes (T1D) remains unclear. This study was to evaluate serum IgA concentrations in Greek children and adolescents with T1D. METHODS: In two hundred individuals with T1D, serum IgA concentrations were quantitatively determined using nephelometry. RESULTS: Immunoglobulin A deficiency was detected in 6 (3.0%) of 200 patients who were subjected to immunological evaluation. Recurrent infections were not recorded, but human papilloma virus infection was clinically suspected and confirmed by laboratory examination in a 5-year-old girl. In regard to coincidence of selective IgA deficiency with autoimmune diseases, celiac disease was detected in a girl and juvenile idiopathic arthritis in a boy. Serum IgA concentrations differed significantly when patients were grouped according to age at the beginning of the study (P<0.001), age at diagnosis of T1D (P=0.015) and coincidence of celiac disease (CD) (P=0.038). However, when the age of the patients was adjusted, difference in serum IgA concentrations was not statistically significant despite CD was present or not. Moreover, serum IgA concentrations were positively correlated with serum IgG (P<0.001) and IgE (P=0.001) concentrations and negatively correlated with serum antigliadin antibody IgG (P=0.035) concentrations. There was no association or correlation of serum IgA concentrations with glycemic control. CONCLUSION: The prevalence of selective IgA deficiency in Greek children and adolescents with T1D is high (3.0%). The correlation of serum IgA concentrations with serum IgG, IgE and anti-gliadin antibody IgG concentrations needs further investigation.

Seronegative Celiac Disease and Immunoglobulin Deficiency: Where to Look in the Submerged Iceberg?

In the present narrative review, we analyzed the relationship between seronegative celiac disease (SNCD) and immunoglobulin deficiencies. For this purpose, we conducted a literature search on the main medical databases. SNCD poses a diagnostic dilemma. Villous blunting, intraepithelial lymphocytes (IELs) count and gluten "challenge" are the most reliable markers. Immunohistochemistry/immunofluorescence tissue transglutaminase (tTG)-targeted mucosal immunoglobulin A (IgA) immune complexes in the intestinal mucosa of SNCD patients may be useful. In our experience, tTG-mRNA was similarly increased in seropositive celiac disease (CD) and suspected SNCD, and strongly correlated with the IELs count. This increase is found even in the IELs' range of 15-25/100 enterocytes, suggesting that there may be a "grey zone" of gluten-related disorders. An immune deregulation (severely lacking B-cell differentiation) underlies the association of SNCD with immunoglobulin deficiencies. Therefore, CD may be linked to autoimmune disorders and immune deficits (common variable immunodeficiency (CVID)/IgA selective deficiency). CVID is a heterogeneous group of antibodies dysfunction, whose association with CD is demonstrated only by the response to a gluten-free diet (GFD). We hypothesized a familial inheritance between CD and CVID. Selective IgA deficiency, commonly associated with CD, accounts for IgA-tTG seronegativity. Selective IgM deficiency (sIgMD) is rare (<300 cases) and associated to CD in 5% of cases. We diagnosed SNCD in a patient affected by sIgMD using the tTG-mRNA assay. One-year GFD induced IgM restoration. This evidence, supporting a link between SNCD and immunoglobulin deficiencies, suggests that we should take a closer look at this association.

Doenças autoimunes e autoanticorpos em pacientes pediátricos e seus parentes de primeiro grau com deficiência de imunoglobulina / Autoimmune diseases and autoantibodies in pediatric patients and their first-degree relatives with immunoglobulin A deficiency

Introdução: As manifestações clínicas da deficiência de imunoglobulina A (DIgA) incluem infecções recorrentes, atopia e doenças autoimunes. No entanto, para o nosso conhecimento, as avaliações concomitantes de doenças autoimunes e autoanticorpos em uma coorte de pacientes com DIgA com idade atual > 10 anos e seus parentes não foram feitas. Objetivos: Avaliar doenças autoimunes e presença de autoanticorpos em pacientes com DIgA e seus parentes de primeiro grau. Métodos: Estudo transversal feito em 34 pacientes com DIgA (idade atual > 10 anos) e em seus parentes de primeiro grau. Todos foram acompanhados em um centro terciário brasileiro para imunodeficiência primária: 27 crianças/adolescentes e sete de seus parentes de primeiro grau com diagnóstico tardio de DIgA. Doenças autoimunes e autoanticorpos (anticorpos antinucleares, fator reumatoide e antitireoglobulina, antitiroperoxidase e anticorpos antiendomísio da classe IgA) também foram avaliadas. Resultados: Doenças autoimunes (n = 14) e/ou autoanticorpos (n = 10, quatro deles com autoanticorpos isolados) foram observadas em 18/34 (53%) dos pacientes e seus parentes. As doenças autoimunes mais comuns encontradas foram tireoidite (18%), artrite crônica (12%) e doença celíaca (6%). Os autoanticorpos mais frequentes foram anticorpos antinucleares (2%), antitireoglobulina e/ou antitireoperoxidase (24%). Nenhuma diferença significativa foi observada no sexo feminino, idade no momento do diagnóstico e idade atual em pacientes com DIgA com e sem doenças autoimunes e/ou presença de autoanticorpos (p > 0,05). As frequências de imunodeficiência de primárias na família, autoimunidade em família, atopia e infecções recorrentes foram semelhantes em ambos os grupos (p> 0,05). Conclusão: Doenças autoimunes e autoanticorpos foram observadas em pacientes com DIgA durante o acompanhamento, o que reforça a necessidade de um acompanhamento rigoroso e contínuo durante a adolescência e a idade adulta. .

Introduction: Clinical manifestations of Immunoglobulin A Deficiency (IgAD) include recur-rent infections, atopy and autoimmune diseases. However, to our knowledge, theconcomitant evaluations of autoimmune diseases and auto antibodies in a cohort of IgADpatients with current age >10 years and their relatives have not been assessed. Objectives: To evaluate autoimmune diseases and the presence of auto antibodies in IgADpatients and their first-degree relatives. Methods: A cross-sectional study was performed in 34 IgAD patients (current age >10years) and their first-degree relatives. All of them were followed at a tertiary Brazilianprimary immunodeficiency center: 27 children/adolescents and 7 of their first-degree rela-tives with a late diagnosis of IgAD. Autoimmune diseases and autoantibodies (antinuclearantibodies, rheumatoid factor, and anti-thyroglobulin, anti-thyroperoxidase and IgA classanti-endomysial antibodies) were also assessed. Results: Autoimmune diseases (n = 14) and/or autoantibodies (n = 10, four of them with iso-lated autoantibodies) were observed in 18/34 (53%) of the patients and their relatives. Themost common autoimmune diseases found were thyroiditis (18%), chronic arthritis (12%)and celiac disease (6%). The most frequent autoantibodies were antinuclear antibodies(2%), anti-thyroglobulin and/or anti-thyroperoxidase (24%). No significant differences wereobserved in the female gender, age at diagnosis and current age in IgAD patients with andwithout autoimmune diseases and/or presence of auto antibodies (p > 0.05). The frequen-cies of primary immunodeficiencies in family, autoimmunity in family, atopy and recurrentinfections were similar in both groups (p > 0.05). Conclusion: Autoimmune diseases and auto antibodies were observed in IgAD patients dur-ing follow-up, reinforcing the necessity of a rigorous and continuous follow-up duringadolescence and adulthood. .

Autoimmunity in patients with selective IgA deficiency.

BACKGROUND AND OBJECTIVE: Selective immunoglobulin A deficiency (SIgAD) is the most common primary antibody deticiency. Patients with SIgAD have a greater risk of concomitant autoimmune disorders than healthy individuals. The exact mechanism underlying the relationship between autoimmunity and SIgAD is not fully understood. The aim of this study was to evaluate potential associations between autoimmunity and specific clinical or immunological findings in patients with SIgAD. METHODS: The study population comprised 57 symptomatic patients (65% males) with confirmed SIgAD who were referred to our center. Demographic data and history of autoimmunity were recorded both for patients and for their relatives. Comprehensive clinical and laboratory examinations were performed to investigate autoimmune complications in all the patients. RESULTS: Autoimmune disorders were documented in 17 cases (29.8%; 9 males and 8 females). The most common manifestations were thyroiditis, vitiligo, and hemolytic anemia (3 cases each). Ten patients (17.5%) had a family history of autoimmunity. Significant associations were detected between autoimmunity and increased duration of follow-up (P = .003), serum level of IgM (P = .01), regulatory T-cell count (P = .03), and class-switched memory B-cell count (P = .01). Four cases of autoimmune SIgAD (23.5%) progressed to common variable immunodeficiency during the follow-up period (P = .006). CONCLUSIONS: Autoimmune disorders, autoimmune cytopenia, and Ig subclass deficiency can lead to severe clinical manifestations in patients with SIgAD. Therefore, immunologists and pediatricians should be aware of these conditions.

Evaluation of serum & salivary IgA in patients with type 1 diabetes.

BACKGROUND: Diabetes mellitus is a common immune mediated disorder. The aim of the present study is to evaluate the level of serum and salivary IgA levels in patients with Type 1 diabetes. MATERIAL AND METHOD: In this case control study, serum and salivary IgA levels of patients with diabetes type 1 and similar non diabetes subjects were measured. Age, gender, duration of diabetes and the last HbA1c level of diabetic patients were also studied. Data was analyzed by SPSS software. RESULTS: Two hundred and fifty subjects (126 diabetics and 124 non diabetics) were enrolled in the study. The mean value of serum IgA in patients with Type 1 Diabetes and controls was 1.77± 1.55 g/lit and 2.39± 1.52 g/lit, respectively. The mean salivary IgA level in diabetics and controls was 276 ± 162.5 40 µg/ml and 129 ± 112.2 40 µg/ml, respectively. Selective IgA deficiency was detected in two (1.6%) and three(2.4%)cases of diabetic and control group; respectively (p=0.68). We found low salivary IgA level in 44.4% diabetic and 33.9% control (p=0.08). There was no significant correlation between serum and salivary IgA level. There was also significant association between serum IgA levels with age. Salivary IgA was significantly correlated with HbA1c level. But considering gender, duration of diabetes we didn't find any association. CONCLUSION: We didn't find any significant difference in serum and salivary IgA level among diabetic and non diabetics and also, no association between serum and salivary IgA levels.

RAG1 deficiency may present clinically as selective IgA deficiency.

BACKGROUND: Recombination-activating gene (RAG) 1 and 2 deficiency is seen in patients with severe combined immunodeficiency (SCID) and Omenn syndrome. However, the spectrum of the disease has recently expanded to include a milder phenotype. OBJECTIVE: We analyzed a 4-year-old boy who was initially given the diagnosis of selective immunoglobulin A deficiency (SIgAD) based on immunoglobulin serum levels without any opportunistic infections, rashes, hepatosplenomegaly, autoimmunity or granulomas. The patient was found to be infected with varicella zoster; however, the clinical course was not serious. He produced antiviral antibodies. METHODS: We performed lymphocyte phenotyping, quantification of T cell receptor excision circles (TRECs) and kappa deleting recombination excision circles (KRECs), an analysis of target sequences of RAG1 and 2, a whole-genome SNP array, an in vitro V(D)J recombination assay, a spectratype analysis of the CDR3 region and a flow cytometric analysis of the bone marrow. RESULTS: Lymphocyte phenotyping demonstrated that the ratio of CD4+ to CD8+ T cells was inverted and the majority of CD4+T cells expressed CD45RO antigens in addition to the almost complete lack of B cells. Furthermore, both TRECs and KRECs were absent. Targeted DNA sequencing and SNP array revealed that the patient carried a deletion of RAG1 and RAG2 genes on the paternally-derived chromosome 11, and two maternally-derived novel RAG1 missense mutations (E455K, R764H). In vitro analysis of recombination activity showed that both RAG1 mutant proteins had low, but residual function. CONCLUSIONS: The current case further expands the phenotypic spectrum of mild presentations of RAG deficiency, and suggests that TRECs and KRECs are useful markers for detecting hidden severe, as well as mild, cases.

[Autoimmune diseases and autoantibodies in pediatric patients and their first-degree relatives with immunoglobulin A deficiency]. / Doenças autoimunes e autoanticorpos em pacientes pediátricos e seus parentes de primeiro grau com deficiência de imunoglobulina.

INTRODUCTION: Clinical manifestations of Immunoglobulin A Deficiency (IgAD) include recurrent infections, atopy and autoimmune diseases. However, to our knowledge, the concomitant evaluations of autoimmune diseases and autoantibodies in a cohort of IgAD patients with current age > 10 years-old and their relatives have not been assessed. OBJECTIVES: To evaluate autoimmune diseases and the presence of autoantibodies in IgAD patients and their first-degree relatives. METHODS: A cross-sectional study was performed in 34 IgAD patients (current age > 10 years-old) and their first-degree relatives. All of them were followed at a tertiary Brazilian primary immunodeficiency center: 27 children/adolescents and 7 of their first-degree relatives with a late diagnosis of IgAD. Autoimmune diseases and autoantibodies (antinuclear antibodies, rheumatoid factor, and anti-thyroglobulin, anti-thyroperoxidase and IgA class anti-endomysial antibodies) were also assessed. RESULTS: Autoimmune diseases (n=14) and/or autoantibodies (n=10, four of them with isolated autoantibodies) were observed in 18/34 (53%) of the patients and their relatives. The most common autoimmune diseases found were thyroiditis (18%), chronic arthritis (12%) and celiac disease (6%). The most frequent autoantibodies were antinuclear antibodies (2%), anti-thyroglobulin and/or anti-thyroperoxidase (24%). No significant differences were observed in the female gender, age at diagnosis and current age in IgAD patients with and without autoimmune diseases and/or presence of autoantibodies (p>0.05). The frequencies of primary immunodeficiency's in family, autoimmunity in family, atopy and recurrent infections were similar in both groups (p>0.05). CONCLUSION: Autoimmune diseases and autoantibodies were observed in IgAD patients during follow-up, reinforcing the necessity of a rigorous and continuous follow-up during adolescence and adulthood.

The higher frequency of IgA deficiency among Swedish twins is not explained by HLA haplotypes.

Serum immunoglobulin A (IgA) concentrations were determined in 12 600 adult Swedish twins, applying a high-throughput reverse-phase protein microarray technique. The prevalence of IgA deficiency (IgAD) was found to be 1:241 in monozygotic (MZ) twins and 1:198 in dizygotic (DZ) twins. Hence, the prevalence in twins is markedly elevated as compared with the normal Swedish adult population (1:600). The twins did not show a difference in the frequency of HLA haplotypes in comparison with almost 40 000 healthy Swedish controls. As expected, the risk-conveying HLA alleles A*01, B*08 and DRB1*01 were overrepresented among the IgAD twins and were also associated with significantly lower mean serum IgA concentrations in the twin cohort. In contrast, significantly higher mean IgA concentrations were found among individuals carrying the protective HLA alleles B*07 and DRB1*15. Exome sequencing data from two MZ twin pairs discordant for the deficiency showed no differences between the siblings. Model fitting analyses derived a heritability of 35% and indicate that genetic influences are modestly important for IgAD. The probandwise concordance rates for IgAD were found to be 31% for MZ and 13% for DZ twins.

IgA deficiency in wolves from Canada and Scandinavia.

Immunoglobulin A deficiency (IgAD) is the most common primary immunodeficiency in both humans and selected breeds of domestic dogs. In both species, IgAD is associated with recurrent infections and immune mediated diseases. Previous results imply that IgAD is also common in the wild ancestor of domestic dogs, the gray wolf. Here, we report that serum IgA concentrations are significantly different in Scandinavian and Canadian wolves (p = 3.252e-15) with an increased prevalence for IgAD in Scandinavian wolves (60%), which is as high as those found in high-risk dog breeds.

Relative IgA-deficient recipients have an increased risk of severe allergic transfusion reactions.

BACKGROUND: Absolute IgA deficiency is the most common immunodeficiency in the Western world. These patients are at risk of severe allergic reactions when receiving a transfusion with a plasma-containing blood product. However, it is unclear whether patients with relative IgA deficiency, that is levels below detection on routine assays, are also at risk of severe reactions. This retrospective study evaluated the number of severe allergic transfusion reactions in relative IgA-deficient patients who were transfused with unwashed blood products. STUDY DESIGN AND METHODS: Patients who had an IgA measurement performed for any reason over a 10-year period were compared with a list of transfusion recipients over the same period. Those who had both an IgA measurement and a transfusion were then compared with the transfusion reaction database to determine whether an allergic reaction had been reported, and if so, the severity of the reaction. Patients with IgA concentrations of <7 mg/dL were defined as relative IgA deficient. RESULTS: Of the 22 362 IgA measurements performed on 19 737 patients over 10 years, a total of 168 relative IgA-deficient patients were identified; 39 of these patients were also transfusion recipients and 4 of 39 (10%) experienced a severe allergic transfusion reaction (SALTR). Eight SALTRs were reported amongst 1545 (0·52%) IgA replete transfusion recipients. CONCLUSION: The significantly increased risk of SALTRs in relative IgA-deficient patients warrants consideration of premedications and/or washing of plasma-containing blood products.