Systemic immunization against IgA in immunoglobulin deficiency.

The presence of serum IgM and IgG antibodies against IgA is common among individuals with IgA deficiency. The route of immunization is still unknown, but it is possible that immunization occurs through the gut. We analysed anti-IgA antibody production in gastrointestinal lavage, saliva and breast milk from patients with IgA deficiency. In no case was there any evidence of local production of anti-IgA antibodies. Immunization may thus be due to exposure to endogenous IgA and therefore represent a 'true' autoimmune phenomenon which may possibly be involved in the pathogenesis of the disease.     

Serum IgE levels in patients with selective IgA deficiency.

In this study serum IgE levels were measured by a double-antibody radioimmunoassay in 31 patients with serum IgA concentration less than 0.01 mg/ml who were followed in the arthritis and allergy clinics. On a group basis there was no significant difference in mean serum IgE levels between the IgA deficient patients and normal subjects of the same age. However, in the absence of atopic disease, IgA deficient patients had significantly lower serum IgE levels. When atopy was associated with IgA deficiency IgE levels were the same as in the normal subjects but significantly lower than those of atopic non-IgA deficient patients. IgE levels in those with recurrent respiratory tract infection were not different. Adults with anti-IgA antibodies had significantly lower IgE values. IgE levels in patients with RA, JRA or SLE were not significantly different. Selective IgA deficient patients may have a relative deficiency of serum IgE depending on the comparison group.     

Synthesis of immunoglobulin and secretory component by gastrointestinal mucosa in patients with hypogammaglobulinaemia or IgA deficiency.

Biopsies of intestinal mucosa from patients with adult hypogammaglobulinaemia or selective IgA deficiency have been studied for the ability to synthesize immunoglobulins and secretory component. Tissue fragments were cultured in vitro in medium containing 14C-labelled amino acids and newly snythesized proteins were detected by radioimmunoelectrophoresis. Synthesis of IgA, and in some cases IgG and IgM, was found in intestinal mucosal biopsies from hypogammaglobulinaemics and IgA-deficient subjects. Biopsies from all the patients also synthesized secretory component, but evidence was obtained which indicated that secretory component does not combine normally with IgA. Tissue sections of these biopsies have also been studied by immunofluorescence and immunoglobulin bearing cells have been demonstrated. The present findings demonstrate that immunoglobulin synthesizing cells are present in the intestinal mucosa of immunoglobulin-deficient individuals. Local immunoglobulin synthesis may partially explain why these patients do not often have major problems with intestinal infections.     

J chain synthesis in lymphocytes from patients with selective IgA deficiency.

J chain synthesis was investigated by in vitro pokeweed mitogen (PWM) stimulated peripheral blood lymphocyte (PBL) cultures in eight patients with selective IgA deficiency and compared with that of normal persons. In normals, all IgM-containing cells always had the J chain but only in a portion of IgG- and IgA-containing cells was J chain detectable. The percentage of J chain-positive cells amongst IgG or IgA cells increased during culture, reached a peak at days 5-6 or 6-7, respectively, and then decreased. IgA-deficient patients had very few IgA-containing cells and an increased number and percentage of J chain-positive IgG cells, except for one patient, who had a significant number of IgA-containing cells without IgA secretion into the culture supernatants. Measurement of Ig in culture supernatants by radioimmunoassay revealed that lymphocytes from seven patients secreted significantly smaller amounts of IgG and IgM than did the normal controls, in addition to the defect in IgA production. These results suggested the presence of some ontogenetic relationship between J chain-positive IgG cells and the precursors of IgA-producing cells, and some functional immaturity of most IgG-producing clones seen in patients with selective IgA deficiency.     

Interferon and beta 2-microglobulin in patients with common variable immunodeficiency or selective IgA deficiency

The production of interferon (IFN) after stimulation of peripheral blood mononuclear cells with Sendai virus or phytohemagglutinin was studied in patients with common variable immunodeficiency (CVID) or selective IgA deficiency. Cells from CVID patients produced significantly more Sendai virus-induced (alpha) and mitogen-induced (gamma) IFN than cells from healthy control subjects. By contrast, some patients with selective IgA deficiency produced subnormal amounts of IFN-alpha. Neither IFN-alpha nor IFN-gamma was detectable in sera from the two categories of patients using radioimmunoassays with sensitivity limits of 5-10 international units per milliliter. With the aid of a more sensitive bioimmunoassay, however, antiviral activity was detected more frequently in sera from patients with CVID than in sera from control individuals. Acid treatment and absorption with anti-IFN-alpha and anti-IFN-beta sera indicated that the antiviral activity was due to IFN, with no preponderance of any particular IFN type. Determination of beta-2-microglobulin (beta 2M) concentrations revealed that CVID patients had markedly, and IgA-deficient patients moderately increased serum levels of this substance, as compared to healthy blood donors. Since IFN enhances the synthesis of beta 2M the finding of increased levels of this substance in CVID would be consistent with the observed hyperproduction of IFN. The present findings are concordant with earlier observations of increased natural killer cell activity in at least some forms of CVID and suggest that increased activity of the IFN/natural killer cell system provides a mechanism which may compensate for the defective B cell function in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

The primary immune response in patients with selective IgA deficiency

The primary immune response in vivo of 20 patients with selective IgA deficiency was studied and compared to controls. The primary cellular immune response tested by dinitrochlorobenzene (DNCB) was decreased in many patients. The primary humoral immune response was elicited by immunization with the test immunogen Helix pomatia haemocyanin (HPH). Using a direct ELISA technique antibodies against HPH of the IgA, IgG and IgM class were measured. Two weeks after immunization no response of IgA anti-HPH was seen except in three patients who showed a low but detectable antibody level. In spite of normal or even elevated serum IgG and IgM levels there was a significantly lower response of the IgG and IgM anti-HPH antibodies at 2 weeks after immunization as compared to the controls followed by a further decline at 6 weeks. We conclude that selective IgA deficiency is often accompanied by more general disturbances in humoral and cellular immunity to newly encountered antigens.     

Immunological investigations in individuals with selective IgA deficiency.

Concentrations of IgG2, IgG4 and IgE were low in 16, 24 and 20% of 25 persons with selective IgA deficiency. Fifty-two per cent had IgD concentrations below 5 iu/ml. Trends for association between any of these parameters and the presence of clinical symptoms were not significant. All patients, except one, had normal amounts of Ig-bearing lymphocytes in the blood. IgG1 antibodies against casein were increased in titre and frequency, whereas IgG4 antibodies were normal. Similar results were found in other sera from persons with selective IgA deficiency.     

Increased concentration of serum IgA antibody to pneumococcal polysaccharides in patients with IgA nephropathy.

It has been postulated that IgA nephropathy (IgAGN) is caused by deposition within the glomerular mesangium of IgA polymers and IgA containing immune complexes which are overproduced in response to antigens presented at mucosal surfaces. To test this, the concentrations of specific antibodies to capsular polysaccharides from pneumococci, which are common commensal and/or pathogenic bacteria in the respiratory tract, have been measured. Sera from 35 patients with IgAGN, six with systemic lupus erythematosus (SLE), eight with membranous glomerulonephritis (MGN) and six with Goodpasture's syndrome (GPS), and from 20 controls (C) were assayed. The concentrations of IgG and IgA antibodies specific for each of five pneumococcal polysaccharides (serotypes 2, 7F, 9N, 14 and 23F) were determined by ELISA. The results from the SLE, MGN and GPS patients were pooled and used as a control group of patients with forms of nephritis other than IgAGN (patient controls, PC). Groups were compared using the Wilcoxon test or the Chi square test. There were no significant differences in the concentrations of IgG antibody to any of the serotypes between the IgAGN and normals, but the PC sera had significantly lower concentrations than either the IgAGN or normals. By contrast, there were no differences between the PC and C in the proportion with detectable IgA antibody to four of the serotypes, but this was significantly increased in IgAGN. There was insufficient IgA antibody to serotype 2 to detect in the assay system used. It is concluded that IgAGN patients have greater concentrations of IgA antibodies, but not IgG, to these pneumococcal polysaccharides, compared with normal controls or patients with other forms of nephritis.     

Helicobacter pylori infection in patients with selective immunoglobulin a deficiency

Selective immunoglobulin A (IgA) deficiency (IgAD) is the most common primary immunodeficiency in the western world. The aim of the study was to investigate the prevalence and clinical characteristics of Helicobacter pylori‐infected dyspeptic patients with IgAD. Case samples were drawn from all subjects ≥ 12 years of age (n = 104729) who had undergone serum total IgA measurements during 2004–14 for any reason at Leumit Healthcare Services (Israel) and had serum total IgA < 0·07 g/l. The control group was comprised of a random sample of remaining patients with a case–control ratio of 10 controls for each case. The dyspeptic diseases were identified and retrieved from Leumit Health Care Services electronic database using specific ICD‐9‐CM diagnostic codes. The case group included 347 subjects and the control group 3470 subjects. There were no significant differences in the prevalence of patients with dyspepsia [84 (24·2%) versus 821 (23·6%) for cases and controls, respectively]. Additionally, there was no difference in a proportion of dyspeptic H. pylori‐positive subjects [59 (17·1%) versus 524 (15·1%)] between the case and control groups. Only 59 (17%) among the 347 IgAD patients underwent gastroscopy. A significantly larger proportion of case subjects experienced several forms of gastritis [13 (61·9%) versus 38 (21·6%), P < 0·001), duodenal ulcers [seven (33·3%) versus 19 (10·8%); P = 0·01] and nodular lymphoid hyperplasia (NLH) [two (9·5%) versus none; P = 0·011]. IgAD is not associated with increased prevalence of H. pylori‐associated dyspepsia; nevertheless, H. pylori‐infected dyspeptic IgAD subjects experience more EGD‐proved gastritis, duodenal ulcers and NLH.     

Genetic and immunologic analysis of a family containing five patients with common-variable immune deficiency or selective IgA deficiency

A family with 13 members included 2 subjects with selective IgA deficiency (IgA-D) and 3 subjects with common-variable immune deficiency (CVID), diseases which usually occur sporadically. Reciprocal combinations of B and T cellsin vitro between one normal and two immune-deficient family members and normal subjects revealed that defective Ig synthesis was determined by the B cells, while the patient T cells functioned normally. Normal T helper and suppressor function was demonstrated even in one patient with CVID who developed a T-cell lymphoproliferative disorder associated with elevated IgM; this patient's B cells made only IgMin vitro. Immune deficiencies were inherited in this family in a pattern consistent with an autosomal dominant trait with incomplete penetrance. All the immune-deficient patients in this family possessed at least one copy of an MHC haplotype previously shown to be abnormally frequent in IgA-D and CVID: HLA-DQB1*0201, HLA-DR3, C4B-Sf, C4A-deleted, G11-15, Bf-0.4, C2-a, HSP70-7.5, TNF-5, HLA-B8, and HLA-A1. The patient who developed the lymphoproliferative disorder was homozygous for this haplotype. Four immunologically normal members, one of whom was 80 years old, also possessed this MHC haplotype, indicating that its presence is not sufficient for disease expression. A small segment of another MHC haplotype associated with Ig deficiency in the population also occurred in this family, but it was not associated with immune deficiency. The presence of neutral amino acids at position 57 of DQ, previously correlated with IgA-D, was associated with disease in this family approximately to the same degree reported previously in unrelated patients. Thus the expression of immunodeficiency in individuals bearing a disease-associated MHC haplotype appears to require either additional genes or an environmental trigger.     

Immunohistochemical study of nasal mucosa in patients with selective IgA deficiency

Fifteen nasal biopsy specimens from adult patients with selective IgA deficiency were examined in a 'blind' immunohistochemical study for the presence of immunocytes producing various immunoglobulin (Ig) classes. Three groups of patients could be identified. One group had a predominance of IgG- and IgM-producing cells in their nasal mucosa, a second group revealed mainly IgG- and IgD-producing cells, and a third group had very few mucosal immunocytes. The clinical examinations showed that upper respiratory tract infections were most common in patients with few immunocytes while such infections were least common in patients with predominance of IgG and IgM immunocytes. Our results indicated that IgM, in contrast to IgD, acts as a compensatory secretory Ig in some patients with selective IgA deficiency.     

Vitamin D deficiency in children with recurrent respiratory infections,with or without immunoglobulin deficiency

Purpose

The objective of this study was to evaluate thevitamin D concentration in patients with recurrent respiratory infections with or without immunoglobulin G, A or M (IgG, IgA, IgM) deficiency, and to find a correlation between the vitamin D concentration and the response to hepatitis B vaccination.

Discontinuation of immunoglobulin replacement therapy in patients with secondary antibody deficiency

ABSTRACT

Introduction

Secondary immunodeficiency is becoming a greater medical concern as the usage of immunosuppressive and biological treatments has increased. Individuals with certain medical conditions, such as hematological malignancies, can also have secondary immunodeficiency. Immunoglobulin replacement therapy (IGRT), which has been used for decades in inherited or primary immunodeficiency, provides some protection to patients with acquired and predominant antibody deficiency, i.e. secondary antibody deficiency (SAD). However, IGRT is costly, and supplies are limited. Although there are clinical guidelines on when to initiate IGRT, there is no guideline on when to discontinue it.     

The association of autoimmune diseases and anti-IgA antibodies in patients with selective IgA deficiency.

The prevalence of antibodies to immunoglobulin A (IgA) was studied in eighty-three subjects with selective IgA deficiency (SIgAD), thirty-three normal individuals, thirty-two children with juvenile rheumatoid arthritis (JRA) and normal or elevated IgA, seventeen children with systemic lupus erythematosus (SLE) and normal or elevated IgA, and thirteen patients with hypogammaglobulinaemia. Anti-IgA antibodies were detected by haemagglutination of human erythrocytes coated with one of two IgA myelomas by the chromic chloride technique. Antibodies to IgA were not found in significant titre in individuals with normal or elevated IgA or in those with hypogammaglobulinaemia. In IgA deficient patients, elevated titres were found in 25--30% of those who were healthy or who had non-rheumatic diseases, 50% of those with rheumatoid arthritis, 77% of those with JRA and 100% of those with SLE. Patients with rheumatic diseases and SIgAD may therefore be particularly at risk of developing anti-IgA-mediated reactions to blood products.     

Milk precipitins in selective IgA deficiency

Precipitating antibody to cow milk's antigens (commonly bovine IgM) is found in 40-50% of selective IgA deficient patients. These precipitins may obscure the diagnosis of selective IgA deficiency by formation of anti-antiserum precipitin rings in radial immunodiffusion. Abnormal immunoregulatory function along with excess absorption of milk antigens in the absence of secretory IgA may be predisposing factors. Elimination of dietary cow's milk results in disappearance of these antibodies.     

Intravenous immunoglobulin therapy for antibody deficiency.

Twenty patients with antibody deficiency were treated at random with either intramuscular immune serum globulin (ISG) or intravenous modified immune serum globulin (M-ISG). Fourteen patients received of 259 M-ISG infusions during 242 months of treatment. Catastrophic vasomotor reactions were not observed. A single dose of 150 mg/kilo M-ISG increased serum IgG values a mean 248 mg%. Intravenous M-ISG therapy was effective in reducing the incidence of acute infections. Subjects receiving M-ISG developed 0.103 acute infections per month of treatment. Patients injected with ISG had 0.295 acute infections per month of treatment. Seven subjects had separate courses of both intravenous M-ISG and intramuscular ISG. Acute infections per month of treatment for M-ISG and ISG were 0.104 and 0.406, respectively.     

Low molecular weight IgM in selective IgA deficiency.

Thirty-nine persons with selective IgA deficiency were studied. These comprised 27 subjects found by population screening and 12 by other means. Low molecular weight (LMW) serum IgM was sought in 28 of the 39 persons. Nine of the 28 (32%) had LMW IgM detectable by a sensitive gel filtration technique. Of 17 patients discovered by screening, five (29%) had LMW IgM. In the nine positive persons, LMW IgM constituted up to 17% of the total serum IgM concentration. Eight of the nine IgA deficient persons with LMW IgM, had clinical disease while associated disease in the entire IgA deficient population was less frequent. Serum immune complexes were demonstrated in five of seven subjects with LMW IgM using a C1q-dependent radioimmunoassay; four of these had immune complex associated disorders, three with polyarthritis and one with glomerulonephritis. Because circulating immune complexes are frequently detected in IgA deficient persons without disease, it is proposed that the presence of LMW serum IgM in IgA deficiency may be associated with disease due to the formation of specific pathogenic immune complexes.     

The relationship of a topic disease and immunoglobulin levels with special reference to selective IgA deficiency

We have confirmed that the presence of IgE in selective IgA deficient patients does not give protection against increased susceptibility to infections. Atopic individuals with selective IgA deficiency may have higher levels of IgE than non-atopic individuals. Immunoglobulin levels for G, A or M tend to be lower in atopic individuals than in normal individuals.