HlA antigens and steroid responsive nephrotic syndrome of childhood

Major histocompatibility complex antigens and immune mechanisms in steroid-responsive nephrotic syndrome

Although the pathogenesis of steroid-responsive nephrotic syndrome (SRNS) is obscure, involvement of an immune mechanism is often suggested. Further evidence of an immune basis for this disorder is an increased frequency of specific major histocompatibility complex (MHC) antigens. In the first part of this study, the phenotypic frequency of HLA-A, -B, -C, -DR antigens were investigated in 30 children with SRNS and in 630 controls. In the second part, total T (CD3+ cells) and B lymphocytes (CD19+ cells) and the lymphocyte subsets (CD4+, CD8+ cells and their ratio) were studied in the same patients and in 30 healthy children. The investigations of all patients were performed during the acute stage and 14 of 30 during remission stage. Human leukocyte antigens (HLA) were determined by standard microlymphocytotoxicity assay and lymphocytes were analyzed by flow cytometry. Human leukocyte antigens A3, DR4, DR7 and the haplotype HLA-A2/B12 showed the strongest association with SRNS. In the studies for cellular immune disorder, CD3+ and CD8+ cells were found to be decreased significantly in the acute stage before beginning steroid therapy. No significant difference in lymphocyte subsets was observed in the remission stage without steroid or immunosuppressive therapy.

HLA class II associations with idiopathic nephrotic syndrome in children

The occasional familial occurrence of idiopathic nephrotic syndrome (NS) points to a genetic predisposition. Reports on associations with certain HLA class II antigens support this hypothesis. In order to define the immunogenetic background of NS more precisely, HLA class II allele frequencies in 161 children with NS were studied by restriction fragment length polymorphism (RFLP) typing. The patient cohorts consisted of 87 children from Southwest-France and 74 from Southwest-Germany. The control group consisted of 118 French and 101 German unrelated individuals from the same geographical areas. HLA alleles were defined in patients with steroid-sensitive (SS) and steroid-resistant (SR) NS and in controls. RFLP typing revealed that the previously reported association between SSNS and HLA-DR7 is confined to the RFLP split 7.1 (DRB1*07) with a combined relative risk (RRcomb) of 6.2. HLA-DQB typing showed an increased frequency of the allele DQB2b (DQB1*0201) (RRcomb = 7.8). HLA-DQA typing showed an association of SSNS with DQA3 (DQA1*0201,0301,0302) (RRcomb = 4.1). The highest RR (16.5) for SSNS was found in German patients who carried the two DRB1 specificities 17.1 (DRB1*0301) and 7.1 (DRB1*07). All associations were stronger in SS patients with frequent relapses or steroid dependency than in non- or infrequent relapsers. SR patients exhibited no significant associations with HLA class II alleles.

HLA antigens in Arab children with steroid-responsive nephrotic syndrome

Forty-eight Arab patients with steroid-responsive childhood nephrotic syndrome were studied for the frequency of HLA-A, -B, -C and -DR antigens. HLA-DR7 was significantly increased in the patient group (63% vs. 28%, P = 0.0002) confirming reports of a DR7 association in other ethnic groups and indicating a universal association with this antigen. HLA-CW6 was also significantly increased (44% vs. 21%, P corr. = 0.042). HLA-DQW1 was significantly reduced in the patients (29% vs. 57%, P corr. = 0.012) as was HLA-CW4 (6% vs. 24%, P corr. = 0.042).

Reduced response to hepatitis B virus vaccination in boys with steroid-sensitive nephrotic syndrome

Vaccination against hepatitis B virus (HBV) was performed in 18 boys (aged 5.7 +/- 2.4 years) suffering from steroid-sensitive nephrotic syndrome (SSNS) and in a control group of 21 healthy boys (aged 5.6 +/- 3.8 years). The percentage of patients who responded to vaccination was significantly lower than the control group 1, 6, 8, 12, 18 and 24 months after the start of vaccination. The titre of antibodies to HBV surface antigen produced by responders at 6 and 24 months was significantly lower in patients than in the control group. Boys with SSNS have an impaired response to HBV vaccination.

Steroid-dependent nephrotic syndrome following renal transplantation for congenital nephrotic syndrome

A boy developed recurrent steroid-responsive nephrotic syndrome following renal transplantation for congenital nephrotic syndrome. The first episode was associated with mild tubulointerstitial rejection on kidney biopsy. Subsequent episodes showed normal histology by light microscopy and epithelial foot process fusion on electron microscopy, consistent with minimal change nephrotic syndrome. Serum analysis for soluble immune response suppressor was negative pre-nephrectomy, positive during each bout of nephrotic syndrome, and negative during each remission. This case represents de novo occurrence of steroid-sensitive minimal change nephrotic syndrome following renal transplantation for congenital nephrotic syndrome. We stress the need for histological examination of the renal allograft to diagnose rejection, recurrent disease, or de novo disease.

Human leucocyte antigens in idiopathic nephrotic syndrome in children

An association of the idiopathic nephrotic syndrome (NS) with certain human leucocyte antigens (HLA) has been reported repeatedly. The aim of this study is to characterize further the clinical and histological features of patients with NS in relation to their HLA phenotypes. HLA antigens were determined in 132 paediatric patients with NS. In 91 steroid-sensitive patients (usually associated with minimal glomerular changes), the antigen frequencies of HLA-DR3, HLA-DR7, and HLA-B8, -DR3 combined were significantly increased compared with controls. The strongest association was observed with the combined occurrence of HLA-B8, -DR3, -DR7 (relative risk 21.5). This association and that with HLA-DR3 alone were strongest in the presence of frequent relapses and steroid dependence compared with children without or with infrequent relapses. The pattern of HLA antigens was similar in the 57 steroid-sensitive patients with biopsy-proven minimal glomerular changes. In 41 children with steroid-resistant NS (usually associated with focal segmental glomerulosclerosis) a similar trend for increased antigen frequencies was found but the data were significant only for the combined occurrence of HLA-B8, -DR3 and -DR7. In all patients combined the frequency of the HLA associations was significantly lower when the age of onset was greater than 8 years compared with that of younger patients. It is concluded that the immunogenetic background of the steroid-sensitive and steroid-resistant NS is different and age-dependent.

HLA extended haplotypes in steroid-sensitive nephrotic syndrome of childhood

Idiopathic nephrotic syndrome has been postulated to have an immunopathogenic basis. To determine whether steroid-sensitive nephrotic syndrome is associated with greater than expected frequencies of specific extended haplotypes of the major histocompatibility complex, we studied genetic markers (Class I, II, III HLA alleles and glyoxalase I) in 173 subjects in 42 families of patients with nephrotic syndrome of childhood. The single allele, DQW2, was found in 72% of steroid sensitive patients compared with only 35% of the controls (P = 0.003). In half of 32 steroid sensitive, but not 10 steroid resistant, patients, one or both of two specific extended haplotypes (alleles that segregate together) were identified. The first, [HLA-A1, B8, DR3, DRW52, SCO1], occurred in 11 of 64 haplotypes, or 17%, compared to 5% of controls (P = 0.017). The other, [HLA-B44, DR7, DRW53, FC31], occurred in 10 of 64 haplotypes, 16% compared to 3.8% of controls (P = 0.014). Five patients had both haplotypes. Patients with these specific extended haplotypes had a greater frequency of relapses than did those with other haplotypes. These data provide additional support for the hypothesis that steroid-sensitive nephrotic syndrome has an immunogenetic basis.

The immune system in minimal change nephrotic syndrome

Numerous examples of abnormal immune responsiveness have been described in minimal change nephrotic syndrome (MCNS). The of MCNS with allergy and with certain genetic markers of immune responsiveness, as well as the excellent response of proteinuria to immunomodulatory agents, has suggested a causal relationship between the immunological and renal abnormalities. However, the nature of this relationship is uncertain. Before it can be clarified, the basic mechanism(s) involved in disturbed immunity in patients with MCNS must be better characterized. Studies of humoral and cellular immune function support the hypothesis that immune regulation is abnormal. However, conclusive evidence of participation by a defined immunoregulatory system in the events leading to immune dysfunction has not been obtained. Thus, considerable work remains to be done in determining the nature and cause of abnormal immunity in MCNS prior to investigating its potential role in the pathogenesis of proteinuria.

Major histocompatibility complex antigens in steroid-responsive nephrotic syndrome

An increased frequency of specific major histocompatibility complex (MHC) class I, II and III antigens in children with steroid-responsive nephrotic syndrome (SRNS) has been reported. This frequency distortion, in some cases, is thought to affect the outcome of the disorder. We studied the phenotypic frequency of HLA antigens -A, -B, and -DR, as well as complement proteins Bf and C4 in an unrelated population of 25 SRNS children. Complete MHC haplotypes were also derived for four families in which 8 individuals developed SRNS. HLA-DR8, with a relative risk of 4.8, showed the strongest association with SRNS. Nonetheless, the 95% confidence intervals of this and the relative risks for all other antigens fell below 1.0. No common haplotype was found in SRNS patients in whom complete family studies were available, and disease and inheritance of the MHC were discordant in two of these families. In this study of well-characterized SRNS patients we were unable to discover a clear association between this disorder and the MHC.

Association of HLA-DRw8 and DQw3 with minimal change nephrotic syndrome in Japanese adults

The HLA systems of forty Japanese patients with adult-onset nephrotic syndrome and biopsy-proven minimal change were investigated. HLA-DRw8 was found in 35% of the patients and HLA-DQw3 in 95%, compared to 12.6 and 63.1% of the control, respectively (DRw8: and Pc less than 0.01, RR = 3.74; DQw3: Pc less than 0.02, RR = 11.1). The phenotype frequencies of all but one HLA-DR antigens, DR4, DR5, DRw8, and DRw9 associating with DQw3, were observed to increase (patient vs. control: DR4, 65 vs. 41.4%; DR5, 10 vs. 4.3%; DRw9, 20 vs. 23%). These results suggest that HLA-DQw3 may be a primary genetic marker associated with a major susceptibility gene to adult-onset minimal change nephrotic syndrome in the Japanese population.

[Idiopathic nephrotic syndrome and the HLA allele. Prevalence of age-related DR7]

High prevalence of HLA DR7 was well documented in idiopathic nephrotic syndrome (INS) of childhood. Our data in 43 INS, child and adult patients, did not show any significant difference from control group, specially for HLA DR7. Moreover a significant difference occurred when the data was compared in child and adult INS patients. HLA DR7 was more frequent when the nephrotic syndrome appeared before 15 years old. There was no correlation between the presence of HLA DR7 and those of allergy history or increased serum IgE level, on the opposite with previous data. The presence of DR7 would favor its onset at an earlier age. Alternatively, the difference in DR7 prevalence could be an additional argument for considering that the corticosensitivity and negative histological criteria might collect, under the same name, different glomerulopathies.

HLA and disease

This review describes the greater portion of a large number of new studies on HLA and disease association which has appeared in the literature since 1979. The majority of these are concerned with the association of certain diseases with class II major histocompatibility complex antigens. The possible biologic significance of these associations in terms of their probable etiology appears to be the prevailing theme. Current thinking regarding certain heritable diseases is described. It seems that although much has been done to resolve the genetics of insulin-dependent diabetes mellitus, other diseases such a multiple sclerosis still remain a mystery. Doubtlessly, much will be gained from DNA cloning and sequencing studies proposed for the future. A great deal of new information has been obtained relative to HLA itself. New loci have been postulated in the HLA-D/DR region through the use of powerful immunochemical procedures made possibly by the advent of modern technological advances. The impact of these developments on our understanding of the function of the MHC in man and its possible relationship to disease are discussed.

Absence of linkage between adult polycystic kidney disease and the major histocompatibility system

Four multiplex families affected with adult polycystic kidney disease were investigated for segregation of the disease with haplotypes bearing HLA-A and B antigens and Bf allotypes. In no case did the disease travel with specific haplotypes within families showing an absence of linkage between the disease and the major histocompatability system. In addition, the disease was not associated with any HLA-A or B antigen or Bf allotype either within or among the families studied.

HLA-DR7 in children with idiopathic nephrotic syndrome. Correlation with atopy

Idiopathic nephrotic syndrome (INS) of childhood is likely to be underlain by an immunopathological mechanism; we investigated the presence of immunogenetic HLA markers in this disease. Fifty-four unrelated INS-affected children, among them 20 with an allergic status, were studied for 33 HLA-A,B and 6 HLA-DR antigens. The results were compared to those obtained in 49 children with glomerulonephritis, 28 children with atopy but without nephropathy, and 91 healthy blood donors. The HLA-A and B antigen frequencies were not significantly different from normal frequencies. The incidence of HLA-DR7 was significantly increased in INS-affected patients as compared to the other groups (66.7% in patients vs 31.1% in healthy controls; corrected P value less than 0.001; relative risk = 4.4), and more so in those with atopy than in those without atopy (90% vs 46%; P = 0.002). The frequency of this antigen is not increased in atopic non-nephrotic children. No relationship between HLA-DR7, clinical outcome and steroid-responsiveness was found. We suggest that the pathogenesis of INS could be influenced by an HLA-linked immune response gene, especially in its atopy associated form.