Failure of long surviving, passively enhanced kidney allografts to provoke T-dependent alloimmunity. II. Retransplantation of (AS X AUG)F1 kidneys from AS primary recipients into (AS X WF)F1 secondary hosts.

Long surviving, passively enhanced (AS X AUG)F1 kidneys carried by AS recipients were retransplanted into (AS X WF)F1 second hosts. Acute graft rejection did not occur. Only one of six secondary recipients mounted a significant T-dependent IgG lymphocytotoxic antibody response. In all six, generation of cytotoxic T cells was markedly slower and depressed. These results are compatible with the hypothesis that kidney parenchyma, although carrying major histocompatibility complex specificity is able to induce T-independent but not T-dependent alloimmunity. A corollary is that passenger cells are responsible for exciting the T-dependent allimmune response normally observed after grafing. The practical difficulty of eliminating all T-dependent immunogenicity from (AS X AUG)F1 kidneys was emphasized by the observation that a 3-d residence in an intermediate AS recipient was insufficient time to prevent acute graft rejection after retransplantation.

Failure of long surviving, passively enhanced kidney allografts to provoke T-dependent alloimmunity. I. Retransplantation of (AS X AUG)F1 kidneys into secondary AS recipients.

Long survival of (AS X AUG)F1 rat kidney allografts in AS recipients was induced by passive enhancement with AS anti-AUG antiserum at the time of grafting. After 1-3 mo, the kidney allografts were transferred to second AS recipients, either naive or sensitized against AUG tissue. Naive second recipients did not reject the grafts acutely and failed to mount T-dependent immunity against AUG targets. When later challenged with spleen cells carrying the AUG haplotype, the naive second AS recipients showed strong IgM, IgG, and cytotoxic T-cell responses after grafting, and the kidneys were rapidly destroyed by immune rejection in all but one rat. It is concluded that long-surviving kidney allografts fail to activate helper T cells and induce in naive second recipients the same state of unresponsiveness observed in the first recipient.

CARD15/NOD2 polymorphisms are associated with severe pulmonary sarcoidosis.

Sarcoidosis and Crohn's disease are heterogeneous systemic diseases characterised by granulomatous inflammation. Caspase recruitment domain (CARD)15 is a major susceptibility gene for Crohn's disease, and specifically for ileal and fibrostenotic subtypes. The C-C chemokine receptor (CCR)5 gene has been associated with both parenchymal pulmonary sarcoidosis and perianal Crohn's disease. This study explored associations between CARD15 polymorphisms, CCR5 haplotype and distinct pulmonary sarcoidosis subtypes. 185 Caucasian sarcoidosis patients were genotyped for CARD15 and CCR5 polymorphisms. The genetic data were compared with 347 healthy controls and were examined for associations with serial pulmonary function tests and chest radiographs. CARD15 genotypes did not differ between the unselected sarcoidosis cohort and controls. However, patients carrying the functional 2104T (702W) polymorphism were more likely to have radiographic stage IV disease at 4-yr follow-up. All patients possessing both CARD15 2104T and CCR5 HHC haplotype had stage IV disease at presentation. Carriage of 2104T was associated with worse forced expiratory volume in 1 s, whereas carriage of the CARD15 1761G (587R) polymorphism was associated with better lung function. For the first time, an association between two CARD15 polymorphisms and specific sarcoidosis phenotypes has been demonstrated, as well as an additive effect of possessing CARD15 2104T and CCR5 HHC haplotype.

CC chemokine receptor 5 gene polymorphisms in beryllium disease.

CC chemokine receptor 5 (CCR5) is expressed on type-1 T-helper cells, which are involved in the pathogenesis of the granulomatous lung disease chronic beryllium disease (CBD). CCR5 gene (CCR5) polymorphisms are associated with sarcoidosis severity. The present study explores associations between CCR5 polymorphisms and CBD and its disease progression. Eight CCR5 polymorphisms were genotyped in CBD (n = 88), beryllium sensitisation (BeS; n = 86) and beryllium-exposed nondiseased controls (n = 173) using PCR with sequence-specific primers. Pulmonary function and bronchoalveolar lavage data were examined for associations with genotypes. There were no significant differences in genotype and allele frequency between CBD, BeS individuals and controls. In CBD, associations were found with decline in forced expiratory volume in 1 s and forced vital capacity and the CCR5 -3458 thymidine (T)T genotype (p<0.0001), and an increase in alveolar-arterial oxygen tension difference at rest (p = 0.003) and at maximum exercise (p = 0.01) and the -5663 adenine allele. Increased bronchoalveolar lavage lymphocyte numbers were associated with CCR5 -2459 guanine/-2135T (p = 0.01) only in the combined CBD and BeS group. This is the first study showing that CCR5 polymorphisms are associated with worsening pulmonary function over time in CBD, suggesting that CCR5 is important in the progression of pulmonary function in CBD. Further studies would be useful to clarify the mechanism whereby CCR5 polymorphisms affect progression of CBD.

Multiplex immune serum biomarker profiling in sarcoidosis and systemic sclerosis.

Multiplex protein technology has the potential to identify biomarkers for the differentiation, classification and improved understanding of the pathogenesis of interstitial lung disease. The aim of this study was to determine whether a 30-inflammatory biomarker panel could discriminate between healthy controls, sarcoidosis and systemic sclerosis (SSc) patients independently of other clinical indicators. We also evaluated whether a panel of biomarkers could differentiate between the presence or absence of lung fibrosis in SSc patients. We measured 30 circulating biomarkers in 20 SSc patients, 21 sarcoidosis patients and 20 healthy controls using Luminex bead technology and used Fisher's discriminant function analysis to establish the groups of classification mediators. There were significant differences in median concentration measurements between study groups for 20 of the mediators but with considerable range overlap between the groups, limiting group differentiation by single analyte measurements. However, a 17-analyte biomarker model correctly classified 90% of study individuals to their respective group and another 14-biomarker panel correctly identified the presence of lung fibrosis in SSc patients. These findings, if they are corroborated by independent studies in other centres, have potential for clinical application and may generate novel insights into the modulation of immune profiles during disease evolution.

A common haplotype of the C-C chemokine receptor 2 gene and HLA-DRB1*0301 are independent genetic risk factors for Löfgren's syndrome.

AIM: Sarcoidosis is a heterogeneous disorder with a strong genetic influence. Genetic factors are also thought to influence disease severity and outcome. We sought to determine whether polymorphisms within CCR2 gene predispose to Löfgren's syndrome--a clinically and genetically distinct sarcoidosis phenotype--and, importantly, whether this association is independent of the known association with the HLA-DRB1*0301 allele. METHODS: We investigated 5 CCR2 variants and HLA-DRB1*0301 by sequence-specific primer (SSP) polymerase chain reaction (PCR) in 176 Spanish (76 Löfgren's syndrome, 100 controls) and 387 Swedish subjects (126 Löfgren's syndrome, 77 non-Löfgren sarcoidosis, 184 controls). RESULTS: One of the deduced haplotypes (CCR2 haplotype 2) was associated with Löfgren's syndrome in both Spanish (OR: 2.03, uncorrected P = 0.02; permuted P = 0.041 vs. controls) and Swedish patients (OR: 3.02, uncorrected P = 0.0007; permuted P = 0.0027 vs. non-Löfgren sarcoidosis; OR: 2.46, uncorrected P = 0.0005; permuted P = 0.0031 vs. controls). HLA-DRB1*0301 allele frequency was also increased in Spanish (OR: 3.52, P = 0.0004 vs. controls) and Swedish patients with Löfgren's syndrome (OR: 10.98, P < 0.0001 vs. non-Löfgren sarcoidosis, OR: 7.71, P < 0.0001 vs. controls). Finally, multivariate analysis revealed that the CCR2 association was independent of HLA-DRB1*0301 in both Spanish (P = 0.02 vs. controls) and Swedish cohorts (P = 0.002 vs. non-Löfgren sarcoidosis, P = 0.001 vs. controls). CONCLUSIONS: This study confirms that CCR2 haplotype 2 and HLA-DRB1*0301 are independent genetic risk factors for Löfgren's syndrome.

The CR1 C5507G polymorphism is not involved in susceptibility to idiopathic pulmonary fibrosis in two European populations.

Idiopathic pulmonary fibrosis (IPF), a severe lung disease with unknown aetiology, is thought to have an important genetic component. Single nucleotide polymorphism, C5507G, of the complement receptor 1 (CR1) gene, which affects the number of CR1 molecules on erythrocytes, has been associated with susceptibility to IPF in a single European population. To replicate this finding, 53 Czech IPF patients with 203 Czech healthy control subjects and 70 English IPF patients with 149 English controls were investigated. In both populations, there were no significant differences in distribution of CR1 C5507G variants between IPF patients and their appropriate control groups. In conclusion, the association of the CR1 C5507G polymorphism with susceptibility to IPF was not reproducible in Czech and English populations.

Relation of mesangial IgA glomerulonephritis to polymorphism of immunoglobulin heavy chain switch region.

We have investigated the switch regions of Ig heavy chain genes of patients with IgA glomerulonephritis (IgA-GN) using restriction fragment length polymorphism (RFLP) analysis. Genomic DNA from patients and controls was digested with the restriction endonuclease Sst I and transferred to nylon membranes using the Southern blot procedure and hybridized with a probe homologous to the switch region of the Ig C mu gene (S mu) which detects RFLPs in both S mu and the switch region of the Ig C alpha 1 gene (S alpha 1). A significant decrease in the frequency of the 2.6;2.1 kb heterozygous S mu phenotype was found in patients with IgA-GN (P = 0.003). With respect to the S alpha 1 region, there was a significant increase in the frequency of the 7.4 kb S alpha 1 phenotype (P = 0.002). In addition, a significant increase in the frequency of the 7.4 kb S alpha 1 allele was found (P = 0.0002). These results suggest that gene(s) within the Ig heavy chain loci may be important in the pathogenesis of IgA-GN.

A variant within the DNA repair gene XRCC3 is associated with the development of melanoma skin cancer.

Exposure to UV radiation is a major risk factor for the development of malignant melanoma. DNA damage caused by UV radiation is thought to play a major role in carcinogenesis induction. Multiprotein pathways involved in repairing UV-DNA damage are the base excision, the nucleotide excision, and the homologous double-stranded DNA repair pathways. This study used a sequence-specific primer PCR (PCR-SSP) genotyping method to investigate the association between polymorphisms in DNA repair genes from these pathways with the development of malignant melanoma. The patient cohort was comprised of 125 individuals with malignant melanoma with lesions or staging suggesting a high risk of relapse or metastatic disease. The control population consisted of 211 individuals. We found the presence of a T allele in exon 7 (position 18067) of the XRCC3 gene was significantly associated with melanoma development (P = 0.004; odds ratio, 2.36; relative risk, 1.74). This gene codes for a protein involved in the homologous pathway of double-stranded DNA repair, thought to repair chromosomal fragmentation, translocations, and deletions. These results may provide further insights into the pathogenesis and the mechanism of UV-radiation induced carcinogenesis as well as having a role in prevention.

Interferon-gamma activates co-ordinate transcription of HLA-DR, DQ, and DP genes in cultured keratinocytes and requires de novo protein synthesis.

The purpose of this study was to determine the effect of interferon-gamma on keratinocyte major histocompatibility complex class II gene transcription. Transformed human foreskin keratinocytes (SVK14 cells) were incubated with recombinant IFN-gamma in the presence or absence of the protein synthesis inhibitor cycloheximide. Total cellular RNA was extracted from the cells and Northern blot analysis carried out using cDNA probes for all the functional class II genes. We report that 1) there is co-ordinate activation of all the class-II genes; 2) the rate of transcription varies between gene loci after activation; and 3) de novo protein synthesis is required for IFN-gamma activation of class II transcription.

Polymorphism of the T cell receptor beta-chain in Graves' disease.

We investigated the T cell antigen receptor constant (TCR beta) beta-chain genes of patients with Graves' disease using restriction fragment length polymorphism analysis. Genomic DNA from patients and normal subjects was digested with the restriction endonuclease Bg1 II, transferred to nylon membranes using the Southern blot technique, and hybridized with a TCR beta probe. A significant increase in the frequency of the 10.0; 9.2-kilobase heterozygous phenotype was found in GD (68.6%) vs. 42.1% in normal subjects (P = 0.003). Using the complex phenotype TCR homozygote (hetero) DR3 as a reference (odds ratio = 1.00), we found that the risk for Graves' disease was restricted to TCR beta heterozygote/DR3+ individuals (odds ratio = 8.31; chi 2 = 11.82; P = 0.0009); in the absence of TCR beta heterozygosity, DR3 was not significantly associated with the disease. These results suggest that TCR beta chain genes also are associated with susceptibility to GD and that the association is most pronounced in (or restricted to) those individuals who are HLA DR3 positive.

Cytokine gene polymorphisms in autoimmune thyroid disease.

Susceptibility to the autoimmune thyroid diseases, Graves' disease (GD) and autoimmune hypothyroidism (AIH), depends on a complex interaction between environmental and genetic factors. The human leukocyte antigen and cytotoxic T lymphocyte-associated-4 regions appear to influence susceptibility to disease, but the effect is not major, and the other genes remain unknown. Cytokines are crucial in the regulation of immune and inflammatory responses and therefore are potential candidate genes for autoimmune thyroid disease. In a case-control study, using a unified method of genotyping, we have examined 15 polymorphisms in 9 cytokine genes in 215 patients with autoimmune thyroid disease (GD, 138; AIH, 77) and 101 normal controls. Polymorphisms in the genes for interleukin-1alpha (IL-1alpha), IL-1beta, IL-1 receptor antagonist, IL-1 receptor 1, IL-4, IL-4 receptor, IL-6, IL-10, and transforming growth factor-beta were investigated. Genotyping was performed using the PCR and sequence-specific primers. Analysis showed a reduced frequency of the variant t allele in the IL-4 promoter polymorphism (position 590) in patients with GD and in the entire patient group (GD and AIH) compared with the control group [corrected P (Pc) = 0.00004 and Pc < 0.00001 for GD and all patients, respectively]. This was reflected in a reduction in the heterozygote genotype in the patient groups compared to the controls [c/t heterozygotes GD, 12%; Pc = 0.06, odds ratio, 0.4 (95% confidence interval, 0.2-0.7); all patients, 11%; Pc = 0.008; odds ratio, 0.4 (95% confidence interval, 0.2-0.7); control subjects, 23%]. There were no significant differences between the study groups for the other polymorphisms examined, and subgroup analysis revealed no association with clinical parameters of disease. These results suggest that an IL-4 variant or a closely linked gene has a modest protective effect against the development of autoimmune thyroid disease, particularly GD. This variation in the IL-4 gene may provide further clues to the pathogenesis of autoimmune thyroid disease and other organ-specific autoimmune diseases. Furthermore, these results suggest that subtle variation in immunoregulatory genes may be associated with autoimmune disease states.

Association between polymorphisms in dopamine metabolic enzymes and tobacco consumption in smokers.

Central dopaminergic reward pathways give rise to dependence and are activated by nicotine. Allelic variants in genes involved in dopamine metabolism may therefore influence the amount of tobacco consumed by smokers. We developed assays for polymorphisms in dopamine beta-hydroxylase (DBH), monoamine oxidase (MAO) and catechol O-methyl transferase (COMT) using the polymerase chain reaction with sequence specific primers (PCR-SSP). We then typed 225 cigarette smokers to assess whether genotype was related to the number of cigarettes smoked a day. Smokers with DBH 1368 GG genotype smoked fewer cigarettes than those with GA/AA [mean difference -2.9 cigarettes, 95% confidence interval (CI) -5.5, -0.4; P = 0.022]. The effect reached statistical significance in women (-3.8, 95% CI -6.4, -1.0, P = 0.007) but not in men (-1.5, 95% CI -6.0, 3.0, P = 0.498). Overall, the effect was greater when analysis was confined to Caucasians (-3.8, 95% CI -6.6, -1.1, P = 0.007). Smokers with MAO-A 1460 TT/TO smoked more cigarettes than those with CC/CT/CO (2.9, 95% CI 0.6, 5.1, P = 0.013). Within each sex group, the trend was similar but not statistically significant (difference for men 2.9, 95% CI -1.0, 6.7; for women 2.0, 95% CI -0.7, 4.8). The effect of the allele was greater in smokers with a high body mass index (> 26) (difference 5.1, 95% CI 1.4, 8.8, P = 0.008). More heavy smokers (> 20 a day) had the DBH 1368A allele when compared to light smokers (< 10 a day). (Relative risk 2.3, 95% CI 1.1, 5.0, P = 0.024.) The trend for increasing prevalence of the DBH A allele in heavy smokers was greater when analysis was restricted to Caucasians (relative risk 3.2, 95% CI 1.3, 8.2, P = 0.004). Conversely, heavy smokers were less likely to have the MAO-A 1460C allele (relative risk 0.3, 95% CI 0.1, 0.7, P = 0.012). Variations in DBH and MAO predict whether a person is a heavy smoker and how many cigarettes they consume. Our results support the view that these enzymes help to determine a smoker's requirement for nicotine and may explain why some people are predisposed to tobacco addiction and why some find it very difficult to stop smoking. This finding has important implications for smoking prevention and offers potential for developing patient-specific therapy for smoking cessation.

HLA class I, II & III genes in confirmed late-onset Alzheimer's disease.

We first examined all the then known alleles (1997) at the HLA-A, B, Bw, C, DRB1, 3, 4 and 5, and DQB1 loci in 55 late-onset (>65y) AD cases and 73 elderly controls from Oxford. We found an association of HLA-B7 with late-onset AD (odds ratio = 3.1, corrected P = 0.04) that was limited to apolipoprotein E epsilon4-negative subjects (odds ratio = 5.1, corrected P = 0.005). We then studied linkages with Class III genes and, finally, we sought to replicate our HLA-B7 result in cohorts from Montreal and Nottingham. Altogether, we used 299 histopathologically confirmed cases of late-onset AD and 175 controls. Our initial, clear finding was not replicated in Montreal and Nottingham, however. We also failed to support any other previously reported association of AD with an HLA gene. Though we cannot exclude distinct linkages in different cohorts as an explanation of the conflicting results of HLA/AD studies, we conclude that there is no compelling evidence of a strong, direct association between late-onset AD and any HLA Class I or II allele.

Connective tissue disease and autoantibodies in the kindreds of 63 patients with systemic sclerosis. The United Kingdom Systemic Sclerosis Study Group.

Systemic sclerosis (SSc) tends to occur in a sporadic fashion and familial occurrence of the disease is unusual. Nevertheless, reports of related connective tissue diseases (CTD), autoantibodies, or both in family members together with associations of certain HLA class II phenotypes with SSc suggest that genetic factors might play a part in susceptibility to the disease. Because of the relative rarity of SSc only a small number of family pedigrees have been studied previously. This report represents the largest study to date, to our knowledge, of family members of patients with scleroderma, and provides the opportunity to investigate the relative importance of genetic and environmental factors operating in the disease. The family pedigrees of 63 patients with systemic sclerosis were examined with respect to clinical, serologic, and immunogenetic features. Multiple cases of SSc were seen only in 1 family, in which the disease affected a father and daughter. Disease expression in these 2 individuals was very similar both clinically and serologically; relatives with other connective tissue diseases were found in 9 families, and nonspecific features of CTD such as Raynaud phenomenon, and arthralgia or arthritis, occurred commonly, especially in female relatives. Antinuclear antibodies (ANA) were also detected more frequently in relatives than in controls. However, antibodies previously demonstrated to have a high degree of specificity for SSc were confined to patients with this disease. Probands had an increase in the frequency of HLA-DR3, DR5, and C4AQO. Patients with diffuse scleroderma had an increased frequency of HLA-DR3, while those with the limited form of the disease had an increased frequency of HLA-DR5.(ABSTRACT TRUNCATED AT 250 WORDS)

A radioimmunoassay of cellular surface antigens on living cells using iodinated soluble protein A from Staphylococcus aureus.

Soluble protein A from Staphylococcus aureus does carry great promise as a marker for cellular surface determinants, due to its specific reaction with, and high affinity for, most subclasses of mammalian IgG. In this article we present the different parameters involved in a radioimmunoassay using 125-I-labelled protein A. Using such an approach the actual technical procedures involved are reported in detail together with tests for mammalian alloantigens, including HL-A in the human, H-2 in the mouse and AgB antigenic sites in the rat, as this presents an unique opportunity to compare them with already widely used assays for transplantation antigens. The different parameters of the assay are analysed in view of measuring with precision quantities of cell-surface IgG molecules, thereby allowing possible determinations of antigenic site numbers in a new and simplified manner.

Enumeration of human alloreactive helper T lymphocyte precursor frequencies by limiting dilution analysis of interleukin-2 production.

We describe a limiting dilution assay for the enumeration of alloreactive interleukin-2 (IL-2) producing helper T lymphocyte precursors (HTLp). In place of the commonly used CTLL cell line, we have employed concanvalin A (ConA) stimulated rat thymocytes as IL-2 responsive indicator cells in a proliferation assay to detect IL-2 levels in limiting dilution microculture supernatants. The proliferation of ConA stimulated thymocytes induced by either recombinant IL-2 or culture supernatants could be blocked by co-incubation with a monoclonal antibody against the rat IL-2 receptor alpha chain, demonstrating the specificity of the response. Our investigations of alloantigen-induced IL-2 production show that (i) a minimum stimulator cell irradiation dose of 50-60 Gy is required to prevent backstimulation of microcultures; (ii) frequencies of alloreactive HTLp are significantly associated with HLA-DR antigen matching between responder and stimulator; (iii) HTLp frequencies detected in assays using B lymphoblastoid cell line stimulators are significantly higher than in assays employing peripheral blood lymphocyte stimulators but possibly reflect a degree of non-specific activation; and (iv) allosensitized responders exhibit altered kinetics of IL-2 production which may permit discrimination between sensitized and naive individuals. Our results both confirm and extend previous reports concerning such features of the alloresponse in humans and demonstrate that ConA stimulated thymocytes are a suitable alternative to CTLL as IL-2 responsive indicator cells in limiting dilution assays for HTLp analysis.

Increased accuracy of renal allograft rejection diagnosis using combined perforin, granzyme B, and Fas ligand fine-needle aspiration immunocytology.

BACKGROUND: Two major routes by which cytotoxic T lymphocytes induce apoptosis in target cells are the perforin-granzyme and the Fas ligand/Fas pathways. Intragraft expression of message for these immune activation genes has been shown to correlate very closely with clinical rejection. We have immunolabeled fine-needle aspiration biopsy samples using a panel of cytotoxic T-cell activation markers to evaluate the immunocytochemical identification of the protein products of these genes in the verification of human renal allograft rejection. METHODS: In this retrospective pilot study, 140 fine-needle aspiration biopsy samples from 50 human renal allografts were labeled using alkaline phosphatase/ anti-alkaline phosphatase immunocytochemistry incorporating monoclonal antibodies to perforin, granzyme B, and Fas ligand. Levels of positive labeling for these markers were compared with the original clinical diagnosis of rejection. RESULTS: An excellent correlation with clinical rejection was obtained when all three antibodies were positive. The false positive rate for each antibody was sufficient to make any one alone or in combination with one other unreliable for diagnosing rejection. When all three antibodies gave positive labeling, agreement with clinical rejection status was superior to using conventional morphological cytology. CONCLUSIONS: In addition to providing valuable morphological information regarding the composition of inflammatory leukocyte populations and the preservation status of renal parenchymal cells, fine-needle aspiration biopsy samples may be labeled using combined perforin, granzyme B, and Fas ligand immunocytochemistry to offer a safe and reliable method for diagnosing rejection with an excellent level of accuracy.

p53 codon 72 polymorphism and susceptibility to skin cancer after renal transplantation.

BACKGROUND: Infection with human papillomavirus (HPV) is an important risk factor for the development of skin cancer after renal transplantation. It has recently been suggested that degradation of the tumor suppressor gene p53 is an important mechanism for human papillomavirus-induced carcinogenesis. A common genomic polymorphism occurs at codon 72 of the p53 gene, and in vitro the codon 72Arg variant appears to be particularly susceptible to degradation. METHODS: To test the hypothesis that this polymorphism predisposes to the development of human papillomavirus-associated tumors, we studied p53 codon 72 genotype in 222 long-term survivors of renal transplantation, of whom 55 had developed at least one skin tumor. RESULTS: No differences in allele or genotype frequency were detected between individuals who had or had not developed skin tumors after transplantation, or any subgroup thereof. CONCLUSIONS: The p53 codon 72Arginine allele does not confer susceptibility to the development of skin tumors after renal transplantation.

Immunoglobulin (Gm) allotype frequencies in idiopathic membranous nephropathy and minimal change nephropathy.

40 Caucasoid patients with idiopathic membranous nephropathy (IMN) and 49 Caucasoid patients with minimal change nephropathy (MCN) were immunoglobulin allotyped for the Gm markers G1m (1, 2, 3) and G3m (5, 11, 21). Compared with normal controls the IMN group had a significantly decreased incidence of the G1m (3); G3m (5, 11) phenotype (P = less than 0.005). This decrease was accompanied by concommitant increase in both the G1m (1, 3); G3m (5, 11, 21) and the G1m (1, 2, 3); G3m (5, 11, 21) phenotypes. The result was most pronounced in IMN patients with deteriorating renal function. In contrast no significant differences were observed between the Gm phenotype frequencies of the MCN patients and controls.