[Determination of phenotypes of haptoglobin and GLM(1) factor of human GM system in stains with admixtures of blood of some fish strains]

It was shown that the phenotypes of haptoglobin (Hg) can not be detected in stains of dried blood of salmon, roach and bream. The results of experimental research of blood of the above fish species are described according to the Cm system. It was proven as possible to identify the human blood in stains with admixtures of blood of the above fish by using the Hp and Cm systems.

[Detection of ABO and GM system antigens in the teeth]

A series of experiments using agglutination inhibition reaction and material extraction in PBS with pH 7.2 (phosphate-buffer-sedin) has been made to detect antigens of the GM system in the teeth. Parameters of the test material/serum ratio are proposed. In parallel, control specimens of blood were examined. The results of the experiments suggest that detection of Gm antigens in the teeth is feasible. In some cases this may raise an identification level of the expert conclusions. The above technique can be used for investigation of the bones.

Differences in idiopathic inflammatory myopathy phenotypes and genotypes between Mesoamerican Mestizos and North American Caucasians: ethnogeographic influences in the genetics and clinical expression of myositis

OBJECTIVE

As part of a larger, worldwide study of the ethnogeography of myositis, we evaluated the clinical, serologic, and immunogenetic features of Mestizo (Mexican and Guatemalan) and North American Caucasian patients with idiopathic inflammatory myopathy (IIM).

METHODS

Clinical manifestations, autoantibodies, HLA-DRB1 and DQA1 alleles, and immunoglobulin Gm/Km allotypes were compared between 138 Mestizos with IIM and 287 Caucasians with IIM, using the same classification criteria and standardized questionnaires.

RESULTS

IIM in Mestizo patients was characterized by a higher proportion of dermatomyositis (69% of adult Mestizos versus 35% of adult Caucasians; P < 0.001) and anti-Mi-2 autoantibodies (30% versus 7% of adults, respectively, and 32% versus 4% of children, respectively; P < 0.01). Genetic risk factors also differed in these populations. Whereas Mestizos had no HLA risk factors for IIM, HLA-DRB1*0301, the linked allele DQA1*0501, and DRB1 alleles sharing the first hypervariable region motif (9)EYSTS(13) were major risk factors in Caucasian patients with IIM. Furthermore, different HLA-DRB1 and DQA1 alleles were associated with anti-Mi-2 autoantibodies (DRB1*04 and DQA1*03 in Mestizos and DRB1*07 and DQA1*02 in Caucasians). Immunoglobulin gamma-chain allotypes Gm(1), Gm(17) (odds ratio for both 11.3, P = 0.008), and Gm(21) (odds ratio 7.3, P = 0.005) and kappa-chain allotype Km(3) (odds ratio 7.3, P = 0.005) were risk factors for IIM in Mestizos; however, no Gm or Km allotypes were risk or protective factors in Caucasians. In addition, Gm and Km phenotypes were unique risk factors (Gm 1,3,17 5,13,21 and Gm 1,17 23 21 and Km 3,3) or protective factors (Km 1,1) for the development of myositis and anti-Mi-2 autoantibodies (Gm 1,2,3,17 23 5,13,21) in adult Mestizos.

CONCLUSION

IIM in Mesoamerican Mestizos differs from IIM in North American Caucasians in the frequency of phenotypic features and in the immune-response genes predisposing to and protecting from myositis and anti-Mi-2 autoantibodies at 4 chromosomal loci. These and other data suggest the likelihood that the expression of IIM is modulated by different genes and environmental exposures around the world.

Gel test assay for IgG subclass detection by GM typing: application to hemolytic disease of the newborn

The gel test assay was evaluated for IgG subclass detection by GM typing of antibodies and compared to the classical inhibition agglutination method on slides or microtiter plates. We used a panel of 5 murine monoclonal antibodies directed against G1M(1), G1M(3), G1M(17), G2M(23), and G3M(21) and 1 human polyclonal anti-G3M(5) antibody. Eleven polyclonal antisera (of immunized women) directed against red blood cells were tested for the GM allotypes carried by their alloantibodies. We controlled the specificity of the gel test reaction using a panel of anti-RH(D) monoclonal antibodies. All reagents exhibited a good reactivity and specificity. They can be used for routine typing. The gel test assay for IgG subclass detection is a specific, simple, and low-cost technique for the detection and management of severe forms of diseases in alloimmunized pregnancies.

GM and KM allotypes in eight tribal populations of Madyha Pradesh and Orissa, India

Serum samples from eight endogamous Indian tribal populations of Madhya Pradesh (Dhurwa, Halba, Bhatra, Muria, Maria) and Orissa (Deshia Khond, Binjhal, Kisan) with a total of n = 731 unrelated individuals were typed for G1M (1,2,3,17), G3M (5,10,11,13,14,15,16,21, 26), and KM (1). In seven of these populations five different GM haplotypes were found: GM* 1,17;21,26; GM* 1,17;10,11,13,15,16; GM* 1,2, 17;21,26; GM* 1,3;5,10,11,13,14,26; and GM* 3;5,10,11,13,14,26. In the Kisan sample the haplotype GM* 1,2,17;21,26 is absent. The intergroup variability in the distribution of these haplotypes is considerable and statistically highly significant. The reasons for that can be attributed to the ethnohistory and to the genetic isolation of these eight endogamous tribal populations. The GM haplotype distribution pattern of all these groups is quite different from that of the non-tribal populations of India, whereas it is in good agreement with that of the so far tested other tribal populations from India. This can be explained by different origin and history of the Indian tribal and non-tribal populations. In the KM system, too, remarkable variability is seen in the distribution of phenotype and allele frequencies among the eight tribal populations under study.

Different Gm allotype amounts in human intravenous immunoglobulin (IVIG) preparations; survival of foreign Gm allotypes in immunodeficient patients

IVIG is used as standard replacement therapy in primary antibody deficiency. IVIG consists mainly of IgG. IVIG preparations were investigated with respect to Gm allotypes, which are characterized by various amino acid epitopes in the constant heavy chains of the IgG subclasses IgG1, IgG2 and IgG3. The alternative allelic Gm allotypes G1m(a) and G1m(f) of IgG1, G2m(n) and G2m(") of IgG2 and G3m(g) and G3m(b) of IgG3 were measured by sensitive competitive ELISAs for G1m(a), G1m(f), G2m(n) and G3m(b). IgG subclass levels were quantified by radioimmunodiffusion (RID). Gm allotype quantities differed significantly in various IVIG products, with different products having half or double the amount of the different Gm allotypes. The results show the effect of the different manufacturing processes, but also indicate different physicochemical properties of Gm allotypes within the same IgG subclass. The different contents of Gm allotypes might be one reason for the variable levels of specific antibodies found in IVIG products. Immunodeficient patients with homozygous expression of Gm allotypes from IGHCG1, IGHCG2 and IGHCG3 were tested after infusion of foreign Gm allotypes. A prolonged survival was found for the G2m allotype, G2m(n), compared with G1m allotypes. Different half-lives were found for the alternative G1m(a) and G1m(f) allotypes, within the same IgG1 subclass.

Immunoglobulin allotypes (GM and KM) and their interactions with HLA antigens in autoimmune diseases: a review

GM and KM immunoglobulin (Ig) allotypes and their interactions with HLA antigens have been analyzed in various autoimmune diseases: multiple sclerosis, rheumatoid arthritis, insulin-dependent diabetes mellitus (IDDM), systemic lupus erythematosus, coeliac disease, Crohn's disease, Graves' disease, atrophic thyroiditis, Hashimoto's thyroiditis, myasthenia gravis, chronic active hepatitis, alopecia areata, uveitis, vitiligo, Turner's syndrome, glomerular nephritis, Berger's disease and idiopathic dilated cardiomyopathy. This review reports published results about associations or linkages, as well as the origins of the populations, the numbers of patients and controls tested. The possible role of Ig polymorphisms in the physiopathology of autoimmune diseases is discussed. Ig allotypes and statistical methods used to analyse the HLA and Ig data are also described.

HLA-DR antigens, Gm allotypes and antiallotypes in early rheumatoid arthritis--their relation to disease progression

OBJECTIVE

Evaluation of the prognostic value of immunogenetic markers in early rheumatoid arthritis (RA).

METHODS

Ninety-nine patients with definite RA and disease duration 24 months or less were followed with standardized assessment. Disability was assessed by the HAQ index and radiographic changes in hands and feet by the Larsen method. The frequencies of HLA-DR genes were determined by serological typing, Gm allotype distribution by classical hemagglutination inhibition test, and occurrence of anti-Gm allotypes by use of anti-Rh coats. The immunogenetic findings were related to disease severity after 2 years' followup.

RESULTS

Functional capacity was well preserved, disease activity was less, but radiographic changes in hands and feet had increased considerably at study finish. A group of 13 patients had developed rapidly progressive changes of hip and/or shoulder joints, all requiring arthroplasty. There was a significantly increased frequency of HLA-DR4. Twenty-seven of the 68 HLA-DR4 positive patients were putatively homozygous. HLA-DR4 was not related to disability or to severe small joint destruction. However, progressive large joint damage was significantly more prevalent in homozygous patients (p < 0.01). Gm allotype distribution was normal and not related to clinical findings. Anti-Gm antibodies were common and frequently specific for nonhost Gm allotype. Fifty-six patients carried anti-G1m(a), and occurrence of this antibody was significantly associated with radiographic progression of small joints (p = 0.01), presence of nodules (p < 0.01) and number of active joints (p = 0.001).

CONCLUSION

Immunogenetic markers aided in identifying patients with early RA with more severe disease.

Transfer of specific immunity from donor to recipient of an allogeneic bone marrow graft: evidence for donor origin of the antibody producing cells

A rapid recovery of specific humoral immunity in the recipient of an allogeneic bone marrow transplantation (BMT) can be observed after immunization of the donor before graft sampling. This has been attributed to transfer of specific immunity from donor to recipient. However, to maintain the concept of transfer the origin of the antibody producing cells in the recipient after BMT must be demonstrated. To this end, donor-recipient pairs with differences in Gm-allotypes were selected and immunized before BMT with the neo-antigen Helix pomatia haemocyanin (HPH) according to three immunization protocols. Additionally, the recipients were immunized at day 42 after BMT. Serum samples were weekly obtained from the recipients in the first 100 d after BMT. The origin of HPH-specific antibody producing cells was assessed by two approaches: (1) determination of the Gm-allotypes of anti-HPH antibodies within a distinct IgG subclass, (2) analysis of anti-HPH antibody spectrotypes by isoelectric focusing combined with immunoblotting. The results obtained with these two approaches show concordance in most instances and led to the conclusion that the antibody producing cells are of donor origin.

Heteroclitic polyclonal and monoclonal anti-Gm(a) and anti-Gm(g) human rheumatoid factors react with epitopes induced in Gm(a-), Gm(g-) IgG by interaction with antigen or by nonspecific aggregation. A possible mechanism for the in vivo generation of rheumatoid factors

Heteroclitic rheumatoid factors (RF) are specific for allotypic determinants, e.g., Gm(a) or Gm(g) on allogeneic, but not autologous IgG. All polyclonal RF we isolated from nine rheumatoid arthritis patients with circulating Gm(a-), (b+), (g-), (f+) IgG displayed dual heteroclitic activity for the Gm(a) and Gm(g) allotypes, as shown by using appropriate RBC agglutination assays and affinity columns bearing Gm(a+) or Gm(g+) IgG. To investigate possible mechanisms underlying the in vivo generation of heteroclitic RF, we tested the ability of nonspecifically and immune-specifically aggregated Gm(a-), (g-) IgG to function as targets for RF from Gm(a-), (g-) patients with rheumatoid arthritis. Heat aggregation (63 degrees C for 20 min) or binding to Ag (as in tetanus toxoid-antitetanus toxoid complexes) induced a "functional" Gm(a+) and/or (g+) phenotype in Gm(a-), (g-) IgG from five healthy subjects and five rheumatoid patients, as suggested by the ability of these altered IgG to function as efficient targets for six heteroclitic RF in direct binding and competitive inhibition experiments. That heterocliticity and dual Gm(a), Gm(g) specificity can be features of a single antibody molecule was formally demonstrated by analysis of a monoclonal RF (IgM mAb 61) generated from a Gm(a-), (g-) rheumatoid patient. RF mAb 61 displayed a high affinity (Kd, 10(-7) M) for IgG Fc fragment of Gm(a+) and (g+) IgG or aggregated autologous Gm(a-), (g-) IgG but did not bind to native autologous IgG. To investigate the molecular basis of the acquired Gm(a) phenotype, PBMC from five Gm(a-) patients with rheumatoid arthritis and two Gm(a-) normal subjects arthritis and two Gm(a-) normal subjects were cultured in vitro after activation with PWM. In most instances, these PBMC produced IgG that behaved as Gm(a+) in sensitive ELISA. Application of the polymerase chain reaction (PCR), using probes specific for the nucleotide sequence coding for the Gm(a) tetrapeptide, to the amplification of DNA from the in vitro-stimulated Gm(a-) normals or rheumatoid patients' PBMC provided no evidence for Gm(a) nucleotide sequences. The present data suggest that acquisition of the Gm(a) determinant by Gm(a-) IgG may result from subtle changes in the CH2-CH3 RF-binding region. Such changes would occur when Gm(a) IgG are complexed with Ag or nonspecifically altered, thereby providing a possible explanation for the induction of heteroclitic RF in Gm(a-) rheumatoid arthritis patients.

Autoantibodies, immunoglobulins and Gm allotypes in nodal generalized osteoarthritis

The frequencies of autoantibodies, including class specific rheumatoid factors, Gm allotypes, and levels of immunoglobulins were determined in 86 patients with nodal generalized osteoarthritis (NGOA), 79 patients with non-nodal large joint osteoarthritis (LJOA), and 90 non-osteoarthritic controls. NGOA patients had a higher frequency of IgG rheumatoid factor (P less than 0.0001) compared to LJOA and normal subjects. Both osteoarthritic groups had lower mean levels of IgA than normals (P less than 0.05), and NGOA patients had a higher frequency of subnormal IgA levels than normals. No differences in other rheumatoid factors nor in frequencies of Gm allotypes were seen. These data support characterization of NGOA as a distinct subset of osteoarthritis, and suggest involvement of immune processes in its pathogenesis.

Regulation of C gamma 3 expression. Role of switch in the allotype-associated variation of human serum IgG3 levels

Serum IgG3 levels are associated with G3m allotypes in humans. However, the molecular basis of this association has not been understood. In this study we have analyzed the biologic half-life, the secretion, the cell surface expression, the cytoplasmic content, and the mRNA expression of different allotypes. The biologic properties of the allotypes did not differ. However, the frequency of cells with membrane IgG3, cytoplasmic IgG3, and C gamma 3 mRNA was decreased in donors with a low serum IgG3, whereas the level of C gamma 3 mRNA expression in individual cells did not differ among cells of the different allotypes. As these findings indicated a pretranscriptional control of C gamma 3 expression, genomic DNA from donors with different allotypes were also studied. Despite the absence of gross, allotype-related differences in the I gamma 3 regions, we favor an upstream cis-element influencing C gamma 3 switching as the most likely explanation for variations in IgG3 serum levels.

Brief communication: immunoglobulin (Gm and Km) allotypes in two populations of Catalonia (Spain)

Serum samples from two populations of Catalonia, Spain, 208 from Olot (Gerona) and 209 from Tortosa (Tarragona), were typed for G1m (1, 2, 3, 17), G3m (5, 10, 11, 13, 14, 15, 16, 26), and Km (1). The Gm patterns of the Catalonian populations are characterized by the presence of four haplotypes, Gm 1,17;21,26 Gm 1,2,17;21,26 Gm 1,3;5,10,11,13,14,26 and Gm 3;5,10,11,13,14,26. The homogeneity for haplotype Gm 1,17;21,26 among our data and other European populations suggests the existence of an isofrequency line which starts from the Mediterranean zone of Iberian Peninsula and continues through the northwestern part of Europe. From this line a decreasing cline towards the south can be observed. For the haplotype Gm 1,2;17,21,26, affinities are observed between Catalonian populations and other populations from central Europe. This confirms the existence of a gradient towards low values from NW to SE. The presence of the typical Mongoloid haplotype Gm 1,3;5,10,11,13,14,26 is discussed in this paper. No significant differences in the frequencies of the Km1 allele were observed among the European populations.

Computer localization of some Gm markers on the surface of the Fc region of human immunoglobulin G

The surface localization of some Gm markers on the Fc fragment of IgG has been identified from previously published amino acid sequences associated with known Gm markers using the atomic coordinates described by Deisenhofer, INSIGHT software and a Digital VAX 11/785 computer, which together permit a study of the three-dimensional structure of the Fc fragment. The G1m(x)-associated amino acid residue 431, the G3m(s)- and G3m(u)-associated residue 435 and the nG4m (a)- and (b)-associated residue 309 are all localized in the interface between the CH2 and CH3 domains. Furthermore, it is postulated that the G1m(a)-associated residue 356 (Asp, Glu) influences the interface formation through an ion pair interaction to Lys 439. Finally, G3m(b) and G3m(g) are associated with the interface via residues 435 and 436. The data explain why sera from patients with rheumatoid arthritis are useful tools for the detection of some Gm markers and support the view that rheumatoid factors from these patients are internal images of microbial Fc-binding proteins.

Ig CH and D14S1 variants in rheumatoid arthritis--linkage and association studies

We have looked for an effect of 14th chromosomal genes linked to immunoglobulin heavy chain (IgCH) or D14S1 regions on susceptibility to rheumatoid arthritis (RA) by both linkage (sibling pair analysis) and association studies. There was no overall linkage between RA and either IgCH or D14S1. However, Gm haplotype similarity in affected siblings appeared greater in either DR4-positive as compared to DR4-negative sibships or in sibships without clinical or serological evidence of autoimmune thyroid disease when compared to sibships with such evidence. In association studies there were no associations at the D14S1 locus. Within the Ig CH region there were no overall associations. However, within the RA population G1m (z) and G3m (g) both appeared less frequent in DR4-negative RA versus both DR4-positive RA and versus control groups. Analysis of DNA variants at Ig CH loci showed differences at the gamma 4 locus with a 9.0 kb fragment appearing less frequently in DR4-positive RA versus DR4-negative RA and control groups. The results suggest a weak or HLA-DR dependent effect of genes linked to the Ig CH region on susceptibility to RA.

Assay restriction profiles of three monoclonal antibodies recognizing the G3m(u) allotype. Development of an allotype specific assay

Three monoclonal antibodies raised against a purified human IgG3 paraprotein were found to exhibit a restriction profile for IgG3/G3m(u) and pan-IgG specificity which was dependent on the assay system. When adapted to an IgG3 subclass capture ELISA, all three McAbs discriminated between paraproteins expressing G3m(u) and antithetical markers G3m(st). One of the antibodies (PNF69C) was selected and conditions were optimised for Gm typing purposes. Using this system G3m(u) could be detected on captured IgG3 derived from human sera. This system may prove useful in the elucidation of Gm allotype profiles.

HLA Gm systems and susceptibility to alcoholic cirrhosis: a study of mixed-race subjects

The fact that only a small percentage of excessive drinkers develop cirrhosis may be due to a genetic susceptibility to the disease. In order to identify possible genetic risk factors for cirrhosis, we studied mixed-race (Negroid-Caucasian) inhabitants of the French West Indies and compared: (1) the frequency of 51 HLA-A, -B, -C and -DR antigens in 41 subjects with alcoholic cirrhosis and in two control groups consisting of 41 excessive drinkers free of liver disease and 51 healthy non-drinkers; and (2) the frequency of Gm and Km haplotypes in the same groups. Analysis of the Gm system also determined the patients' ethnic origins. The frequency of the HLA-A2 antigen was significantly higher in the cirrhotic patients than in the control group of excessive drinkers (chi 2 = 4.47; P less than 0.05), while that of the HLA-B15 antigen was significantly lower (chi 2 = 5.14; P less than 0.05). The frequency of the Cw4 antigen was significantly higher in the cirrhotics than in the non-drinkers (chi 2 = 5.59; P less than 0.05). However, these differences did not persist when the number of comparisons was taken into account. The frequency of Gm and Km haplotypes was not significantly different in the three groups. In conclusion, complementary studies are required to determine the value of the Gm-Km system as a marker of susceptibility to alcoholic cirrhosis. Our results do not identify an association between HLA antigens and cirrhosis specific to a negroid ethnic group and support the notion that such an association is weak.

Immunoglobulin allotypes in several North American Eskimo populations

Genetic data consisting of immunoglobulin testing (GM and KM) from 631 Eskimos from 5 populations are reported. These populations are Savoonga, Gambell (St. Lawrence Island), Wales, King Island, and Mckenzie Delta, Baffin Island. The GM and KM haplotypes are analyzed and compared to those occurring in Greenland, Canadian, Alaskan, and Siberian Eskimos and to other Siberian indigenous populations. These analyses suggest that during the peopling of the New World, four separate migrant groups crossed Beringia at various times.

G3M T typing by dot immunobinding with monoclonal anti-G3M T antibody

Dilutions of 100 serum samples of various GM phenotypes were dotted onto a nitrocellulose membrane. The serum dot-blots were detected with peroxidase-labeled anti-G3M T monoclonal antibody (anti-G3M T MAb). Up to a 1 : 256 dilution could be G3M T-typed correctly. By use of anti-G3M T MAb and peroxidase-labeled anti-mouse IgG or the biotin-avidin system instead of use of labeled anti-G3M T MAb, up to a 1 : 512 or 1 : 1024, respectively, dilution was typable. As with previous work with G3M G MAb, the dot immunobinding (DIB) method for G3M T typing was found very simple and practical.

Practical method for production of monoclonal antibody to human IgG allotype G1M F and its applications in ELISAs and dot immunobinding

An anti-G1M F monoclonal antibody was produced by immunization of mice with a single dose of F(ab')2 fragments of normal IgG1-enriched IgG and subsequent fusion of their lymph node cells with P3U1 myeloma cells. Antibody specificity was tested by an ELISA in microtiter plates coated with allotype positive or negative IgG. The usefulness of the antibody as a G1M F typing reagent in inhibition and direct immobilization-type ELISAs and dot immunobinding was demonstrated by re-typing of 100 GM-allotyping control sera. The advantages and disadvantages of these assay methods are discussed.

Immunogenetics of early-onset insulin-dependent diabetes mellitus among the Japanese: HLA, Gm, BF, GLO, and organ-specific autoantibodies--the J.D.S. study

The Japan Diabetes Society (JDS) conducted a multicenter study on the immunogenetics of early-onset insulin-dependent diabetes mellitus (IDDM) of the Japanese. Human leukocyte antigen (HLA), properdin factor B (BF), immunoglobulin heavy-chain complex (Gm), and glyoxalase of erythrocytes (GLO) were typed, and organ-specific autoantibodies, including islet cell antibody (ICA), were assayed in 159 Japanese IDDM patients and their family members and in 258 healthy Japanese controls. The HLA-DRw9 phenotype and HLA-Bw61/DRw9 haplotype were significantly increased among the patients with autoantibodies other than ICA but with no autoimmune diseases (RR = 5.84, cP less than 0.001; and RR = 7.45, P less than 0.001), whereas the HLA-DR4 phenotype and HLA-Bw54/DR4 haplotype were significantly increased in those without either the autoantibodies or autoimmune diseases (RR = 2.64, cP less than 0.001; and RR = 4.55, P less than 0.001). The HLA-DR4 phenotype was significantly increased in the patients with autoimmune thyroid diseases (RR = 6.21, cP less than 0.05). In all groups of patients, the HLA-DR2 phenotype was significantly decreased, and the relative risk of the HLA-DRw9/DR4 genotype was highest among all HLA-DR genotypes. No significant association was found between HLA type and the duration or incidence of ICA. Gm types of g and gft were significantly increased in the patients with the autoantibodies (RR = 2.11, P less than 0.05; and RR = 34.11, P less than 0.05), whereas the BF-F phenotype was significantly decreased in the patients either with or without autoantibodies (RR = 0.43, P less than 0.05; and RR = 0.46, P less than 0.05). There was no association between IDDM and GLO type. These data indicate that immunogenetic bases underlying IDDM of the Japanese are heterogeneous, as are those in Caucasians.

Lack of the G2m(n) allotype in IgG subclass deficiency, in IgG2 deficiency together with lack of G1m(a) and G3m(g), and in IgG3 deficiency together with lack of G1m(f) and G3m(b)

Lack of G2m(n) was demonstrated in both IgG2-deficient and IgG3-deficient Caucasian patients. Lack of G2m(n) or G2m(",") was found together with homozygosity for both G1m and G3m allotypes as the dominant finding, i.e. for IgG2-deficient patients together with G1m (f,f) and G3m(b,b), constituting the Gm(f,",b) phenotype, and for IgG3-deficient patients together with G1m(a,a) and G3m(g,g), constituting the Gm(a,",g) phenotype. The group with IgG2 deficiency and the selected patients with the Gm(f,",b) phenotype expressed characteristically very low or undetectable IgG4, significantly increased IgG3, and normal IgG1. The group with IgG3 deficiency and the selected patients with the phenotype Gm(a,",g) expressed instead normal IgG4 and nearly normal IgG2 and IgG1 levels. The lack of G2m(n) together with lack of one or the other of the alternative G1m genes and corresponding G3m genes give different IgG2 levels and different IgG subclass patterns. The frequency of G1m allotypes and corresponding G3m allotypes also deviated significantly when the IgG2 deficiency and IgG3 deficiency groups were compared with each other. Most IgG subclass-deficient patients are homozygous in the Gm system and lack genetic variants in the three IgG subclasses, IgG1, IgG2, and IgG3.

Gm/Km typing of bloodstains in U-bottom microtiter plates

A technique was developed for Gm/Km typing of bloodstains and sera in U-bottom microtiter plates. Gm/Km typing of sweat and urine samples was also attempted with limited success.

Correlation between atopy and Gm allotypes

In 50 consecutive atopic Caucasian patients with increased IgE greater than 600 kU/l, the phenotypic Gm allotype constellation deviated from that to be expected, with significantly increased frequency of patients with the phenotype Gm(f,n,b). There was an increased frequency of the G2m(n) allotype, more frequent in patients with IgE greater than 1,000 kU/l, and in patients with IgG4 greater than 1 g/l. In patients with IgE greater than 1,000 kU/l the phenotype Gm(a,f,n,b) was significantly increased and in patients with IgG4 greater than 1 g/l the phenotype Gm(f,n,b) was significantly increased. Those atopic patients with increased IgE and increased IgG4, according to earlier studies known to have the most severe forms of the disease, were thus mainly found to have the m(f,n,b) phenotype.

Possible disorder of B-cell-related surveillance and malignant lymphoma of the thyroid

Malignant lymphoma of the thyroid has been shown to be of B-cell origin. To clarify its genetic origin, we have investigated HLA-A, B, C, and DR antigens, and the immunoglobulin G (IgG) heavy-chain allotype, Gm, in such patients. There was no correlation between the occurrence of malignant lymphoma of the thyroid and the HLA antigens tested, but patients with this lymphoma had significantly lower frequency of the Gm1,21 haplotype than healthy persons. These results suggested a disorder of surveillance related to B-cells may be involved in the pathogenesis of malignant lymphoma of the thyroid.

Familial steatocystoma multiplex: HLA, Gm, Km genotyping and chromosomal analysis in two unrelated families

Steatocystoma Multiplex (S.M.) is an inherited condition characterized by the appearance of cysts during the first or second decade of life. Familial cases have occasionally been reported. We studied 13 patients affected by S.M. from two unrelated families, focusing our attention on HLA, Gm and Km genotypes and on chromosomal analyses. Although we failed to correlate the syndrome with a particular HLA, Gm or Km haplotype, we report some peculiarities and differences between these two families and the healthy Italian population.

Distribution of Gm allotypes among the three populations of the Miyako Islands in Okinawa

Serum samples from 738 unrelated individuals of three populations in the Miyako Islands were tested for twelve Gm allotypes to investigate the variability of phenotypes and haplotypes. Nine phenotypes observed in these populations as well as mainland Japanese could be explained by the presence of the four Gm haplotypes, ag, axg, ab3st, and afb1b3. A good agreement was obtained in the samples of each populations between the observed and expected frequencies on the basis of the Hardy-Weinberg equilibrium of phenotypes. These populations showed remarkable heterogeneities with one another on the basis of Gm haplotype frequency analysis. Moreover they exhibited no homogeneities with the Ryukyuans nor with the mainland Japanese. Homogeneity was found between the Ainu and the people in Ueno village but not in the other two locations. However, Gm xg haplotype, only detected in the Ainu, was not found in Ueno. These may imply a racial relationship between the Ainu and the inhabitants in Miyako in the remote past. However, there is no certainty that both of Ainu and the people in Ueno derived from the same origin, or that genetic drift due to endogamy in this village took place. The Gm phenotype and haplotype frequencies observed in Miyako show that they belong to the northern mongoloid group characterized by a high frequency of Gm ag and an extremely low frequency of Gm afb1b3. It is therefore reasonable to assume that they came from northern Asia as well as mainland Japanese.

Ig allotype-linked regulation of class and subclass composition of natural antibodies to group A streptococcal carbohydrate

To determine the importance of genes located in or near the Ig constant regions in regulating the human antibody response, we correlated Ig allotypic markers with total Ig concentrations and natural antibody concentrations to the streptococcal group A carbohydrate (A-CHO) in 193 healthy adult blood donors. The major correlations between Ig allotypes and total Ig and specific antibody concentrations were observed with the Gm(f;n;b) haplotype. When compared with Gm(f;n;b) negative individuals, Gm(f;n;b) positives had significantly higher concentrations of total IgG2 (p less than 0.001) and IgG2 anti A-CHO (p less than 0.05), lower concentrations of total IgG1 (p less than 0.001) and IgG1 anti A-CHO (p less than 0.001), and lower concentrations of total IgM (p less than 0.001) and IgM anti A-CHO (p less than 0.05). We conclude that individuals with the Gm(f;n;b) haplotype respond preferentially with IgG2 rather than IgG1 subclass antibodies. This increased capacity to respond with IgG2 antibodies may be reflected in the magnitude of the total antibody response when the IgG2 subclass comprises a major proportion of the response, as occurs in the adult response to many polysaccharide Ag.

[An amino acid substitution determining G1m(x) allotypic marker]

We confirmed the amino acid substitution responsible for G1m(x) allotypic marker, which was estimated by Cook & Steinberg (Mol. Immunol. 16:555-558 (1979), by primary structure analysis of the C-terminal BrCN peptide from normal human IgG1 carrying G1m(x+) or G1m(x-). The results indicate that IgG1 carrying G1m(x) have glycine instead of alanine at position 431 (Eu numbering). And we discussed the epitope on tertiary structure of IgG1-Fc fragment.

Autoantibody formation after bone marrow transplantation. Comparison between acetylcholine receptor antibodies and other autoantibodies and analysis of HLA and Gm markers

Clinical myasthenia gravis has been reported in an increased frequency after bone marrow grafting. The number of bone marrow transplanted patients making IgG autoantibodies directed against the autoantigens cardiolipin, SS-B (La) and thyroglobulin was found to be significantly lower as compared to the autoantigen acetylcholine receptor protein. The occurrence of antibodies to single-stranded DNA was found in a lower frequency than acetylcholine receptor antibodies but the difference was not statistically significant. Antibodies to cardiolipin were frequently observed prior to grafting. The G1m1,2 and G3m5 phenotype frequency did not differ in individuals who developed receptor antibodies from that found in the normal population. Analysis of HLA antigens in this patient group revealed no association to HLA B8/DR3 or B35/DR1. This may indicate that the etiology of myasthenia gravis induced by bone marrow grafting differs as compared with the spontaneous form of myasthenia gravis and the penicillamine-induced disease.

Immunoglobulin allotyping (Gm, Km) of GAW5 families

The following Gm and Km immunoglobulin allotypes were determined on the Genetic Analysis Workshop 5 insulin-dependent diabetes mellitus (GAW5 IDDM) families: G1m (1,2,3,17), G2m (23), G3m (5,10,11,13,14,21,28) and Km (1,3). Since the allotype G2m (23) has been rarely studied, due to paucity of typing reagents, it was of interest to compare the frequency of the halotype encoding this allotype in parents of North American GAW5 IDDM families with the frequency found in a previous investigation of healthy North Americans. Results indicated very similar frequencies of Gm haplotypes in the two groups.

Genetic analysis of IDDM: the GAW5 multiplex family dataset

In a collaborative effort by 12 centers from Europe and North America, data were assembled from 94 multiplex families with insulin-dependent diabetes mellitus (IDDM) for analysis of genetic and other factors of possible etiological importance. The dataset contains information on the following genetic markers: HLA-DR beta and -DQ beta restriction fragment length polymorphisms (RFLPs), three RFLPs detected with two probes that map 5' to the insulin gene, the serologically defined HLA loci, and the immunoglobulin allotypes. Data also were included for auto-antibodies to insulin and pancreatic islet cells as possible indicators of pathogenesis and for antibodies to certain viruses that have been implicated as "triggering" agents in IDDM. Medical history of family members was obtained by means of a uniform questionnaire. Identical copies of the dataset were distributed to anyone wishing to participate in the analysis for the IDDM component of GAW5. The multiplex IDDM family dataset is now available on request for further analysis.

Immunoglobulin allotype Gm(1,2;21) in ankylosing spondylitis with peripheral arthritis

Frequencies of immunoglobulin G (Gm) allotypes were determined in 240 patients with ankylosing spondylitis (AS). The uncommon phenotype Gm(1,2;21) was increased in frequency in 55 patients with AS and peripheral arthritis (14.5% v 3.5% of healthy blood donors; p less than 0.05). In 16 patients with arthritis only of wrist/hand or ankle/forefoot, or both, the Gm(1,2;21) frequency was even higher (31.3%; p less than 0.0005). Patients with AS negative for the HLA antigen B27 (n = 28) differed from the B27 positive patients (n = 205) with regard to the frequency of the Gm(1,2,3;5,21) phenotype (39.3% v 9.3%; p less than 0.0005). These findings support the notion of genetic heterogeneity among patients with AS.

Chromosome 14 markers in rheumatoid arthritis

Phenotype frequencies for variants of the chromosome 14 markers, alpha 1 antitrypsin (protease inhibitor--Pi), and immunoglobulin heavy chain gene allotypes (Gm and Am) were examined in affected and unaffected members of multicase rheumatoid arthritis (RA) families and compared with published population data. Significantly higher frequencies of phenotypes containing Pi*Z and Pi*S were observed in unrelated index RA cases compared with UK population data. There was also a higher frequency of Pi*Z in family members without RA than in population controls but no such difference for the frequency of Pi*S. No difference in the frequency of PiM1M2 heterozygotes was seen between patients with RA and population controls. An examination of clinical data failed to show any relation between any particular feature of RA and positivity for Pi*Z or Pi*S. No significant differences in frequency of Gm phenotypes were observed between patients with RA and controls. Significant association was found, however, between Pi*Z and Gm phenotypes containing Gm(zax;g). These associations are interpreted as indicating linkage disequilibria between these alleles. No interactions between DR4 and either G1m(z), (a), or (x) allotypes were apparent in patients with RA. A significant association was seen in the index RA cases between DR4 and Pi phenotypes carrying Z or S alleles. Observations from this study provide evidence for the existence of a genetic component for RA susceptibility encoded on chromosome 14. An interactive effect of these genes with DR4 towards susceptibility appears likely.

Immunoglobulin (GM and KM) allotypes and relation to population history in native peoples of British Columbia: Haida and Bella Coola

Differences in the frequencies of GM haplotypes among native peoples of the Americas support the hypothesis that there were three distinct waves of migration from northeast Asia into the Americas: Paleo-Indian, Na-Dene, and Inuit (Eskimo)-Aleut (Salzano and Steinberg: Am. J. Hum. Genet. 17:273-279, 1965; Sukernik and Osipova: Hum. Genet. 61:148-153, 1982; Williams et al.:Am. J. Phys. Anthropol. 66:1-19, 1985; Szathmary: In R Kirk and E Szathmary (eds): Out of Asia: Peopling of the Americas and the Pacific. Canberra: The Journal of Pacific History, Canberra Australian National University, pp. 79-104, 1985). We studied GM allotypes in two linguistically unique populations of Canadian west coast native peoples, the Haida and the Bella Coola, and compared them to GM frequencies in populations that are supposed descendants of the three migrations, in order to investigate the possible genetic relationships of these British Columbia (BC) groups to other native populations. We also estimated the amount of European admixture from the frequency of the Caucasian haplotype, Gm3;5. Results showed that the frequencies in both BC populations of the three common native haplotypes (Gm1,17;21, Gm1,2,17;21, and Gm1,17;15,16), were intermediate between the frequencies in supposed descendants of Paleo-Indian and Na-Dene. These genetic findings are consistent with the controversial hypothesis of archeologist C. Borden (Science 203:963-971, 1979) that, following deglaciation about 13,000 years ago, British Columbia was repopulated by peoples from the north (?Na-Dene) and by culturally distinct peoples from the south (?Paleo-Indian). Caucasian admixture estimates suggested that the Haida and Bella Coola have also experienced moderate amounts (12-20%) of genetic input from European-originating peoples.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidemiological and genetic aspects of IgM rheumatoid factors

The occurrence of IgM rheumatoid factors (RF) was studied in a random sample of 8807 persons aged between 20 and 50 years in Tromsø, North Norway. Seropositivity for IgM RF was defined as a Waaler titre of 40 or more. A total prevalence of IgM RF of 1.36% was found, and a prevalence between 0.48-0.94% was found among the healthy persons, with no sex difference. Approximately 50% of IgM Rf positives are thus healthy. Only 11% of those with IgM RF suffered from rheumatoid arthritis. The majority of RF positive sera from healthy persons were low titred, and 81% of them converted to seronegativity in the course of 3.5 years. A low titred IgM RF appears rather harmless, while a high titre indicates a specific disease process. No association between IgM RF and DR4 could be found in healthy persons. The frequencies of Gm-allotypes a, b, e, f-n and x in healthy, RF positive individuals did not differ from the RF positive patients with RA, suggesting that the Gm-allotypes are not involved in the genetic pre-disposition for RA.

Immunoglobulin allotypes and immunoreactivity in chronic liver disease

The immunoglobulin allotypes Gm (a; x; f) and Km 1 have been estimated in 194 patients with chronic liver disease, and compared with the frequency distribution of a representative reference group (Gm : n = 2171; Km : n = 2179). In relation to the Gm phenotypes we have investigated the cell-mediated immunoreactivity by the E rosette test, lymphocyte transformation test and migration inhibition test. Virus-induced chronic liver disease showed significantly higher prevalence of the phenotypes Gm a+x-f+ and Gm a+x+f+ as well as of the marker Km + 1 (p less than or equal to 5%; chi 2-test). In auto-immune chronic liver disease we observed a decrease in the phenotype Gm a+x-f+ while the factor Km + 1 was significantly multiplied. Patients with cryptogenic and alcoholic hepatopathy showed no differences in comparison with the reference group. In the progressive forms of the chronic liver disease (chronic active hepatitis, liver cirrhosis) Gm a+x+f+ was significantly more frequent. The investigations concerning cell-mediated immunity in different Gm allotypes generally showed a trend to increased reactivity in Gm a+x+ in comparison with Gm a-x- in non-alcoholic liver disease. It is possible to presume different genetic and immunologic situations in the various liver diseases as endogenous factors promoting the disease.

C2 deficiency, moderately low IgG2 concentrations and lack of the G2m(23) allotype marker in a child with repeated bacterial infections

C2 deficiency was demonstrated in an 11-year-old boy with a past history of recurrent purulent otitis media, pneumonia, H. influenzae meningitis and S. pneumoniae septicaemia. The major histocompatibility complex haplotypes present, A10, B18, DR2, BF*S, C2*QO, C4*A4, C4*B2 and A28, B18, DR2, BF*S, C2*Q0, C4*A4, C4*B2, were in accord with previous observations in C2 deficiency. The concentrations of C1q, C5, factor B and factor D were in the low normal range and the hemolytic activity of the alternative pathway was slightly decreased. In addition, the patient showed moderately low IgG2 concentrations and lacked the IgG2 subclass marker G2m(23). The findings indicate that the patient's susceptibility to bacterial infections may be due to C2 deficiency in combination with the presence of an IgG allotype associated with impaired antibody responses to carbohydrate antigens.

Gm allotypes and HLA in rheumatoid arthritis patients with circulating antibodies to native type II collagen

HLA antigens and immunoglobulin heavy chain allotypes (Gm) were determined in 166 unrelated patients with rheumatoid arthritis (RA), 44 of whom had circulating antibodies to native type II collagen. Collagen antibody positive patients showed an association with HLA-DR3 and DR7 (68% compared with 39% of collagen antibody negative RA, p less than 0.005), and with the Gm phenotype, Gm(zafngb). This contrasted with the collagen antibody negative RA patients where there was an association with HLA-DR4 and, in DR4 positive disease only, with the Gm allotype, G1m(x). The Gm(zafngb) phenotype was found in 26% of DR3 or DR7 positive patients overall and only 9% of RA patients negative for these DR antigens (p less than 0.005), suggesting an interaction between HLA-DR3/7 and Gm(zafngb). The differing Gm associations for collagen antibody positive and negative RA provide further evidence for genetic heterogeneity in susceptibility to RA.

Gm allotyping to determine the origin of the anti-D causing hemolytic anemia in a kidney transplant recipient

Anti-D causing mild hemolytic anemia was found in the serum and on the red cells of a D-positive patient who had received a kidney transplant from his D-negative mother. Anti-D had been detected in the donor's serum before transplantation. Gm allotyping of the patient's serum, donor's serum, donor's anti-D, and the unexpected anti-D in the posttransplantation serum showed the antibody to be of maternal origin. The patient was Gm(fb), the donor Gm(agfb), the maternal anti-D Gm (afb), and the anti-D in the posttransplantation serum was Gm(a).

HLA-DR4 and Gm(1,3;5,21) are associated with U1-nRNP antibody positive connective tissue disease

Patients with U1-nRNP antibodies (n = 35, 31 female, four male) were typed for HLA-A, -B, -C, and -DR antigens and IgG heavy chain allotypes G1m(1), -(2), -(3), G3m(5), and -(21). The patient group was clinically heterogeneous. Four met the American Rheumatism Association criteria for systemic lupus erythematosus, six for progressive scleroderma, and 14 for rheumatoid arthritis. Sicca syndrome was present in seven cases. Twenty three had overlapping features compatible with mixed connective tissue disease (MCTD). Healthy blood donors served as controls for HLA typing (n = 64), Gm typing (n = 228), or both (n = 56). Sixty six per cent of the patients with U1-nRNP antibodies were DR4 positive compared with 28% of the controls (relative risk = 4.9, p = 0.00053). The Gm(1,3;5,21) phenotype was found in 46% of the patients and 25% of the controls (relative risk = 2.47, p = 0.0247). Within the patient group Gm(1,3;5,21) was found only in DR4 positive individuals. The coincidence of HLA-DR4 and Gm(1,3;5,21) increases the relative risk values to 8.0 (compared with the group with neither risk factor). DR4 and Gm(1,3;5,21) primarily seem to be related to U1-nRNP antibody formation and not to disease expression. Patients with or without MCTD did not differ with respect to DR4 or Gm(1,3;5,21) frequency. Disease onset was earlier in patients with HLA-DR4/Gm(1,3;5,21) than in patients without both markers (mean 27.9 v 40.1 years; p less than 0.05).

Immunoglobulin (Gm and Km) allotypes in nine endogamous groups of West Bengal, India

Blood samples from 898 individuals of nine endogamous groups of West Bengal, India were typed for determining the haplotypic structure in the gamma-light chain (Gm) and kappa-light chain (Km) of immunoglobulin (IgG). The Gm haplotype frequencies detected by Glm (1), Glm (2) and G3m (5) markers suggest that in this eastern state of India there is considerable variation of frequencies of the typical Mongoloid haplotype Gm1,5, which shows a high incidence in Rajbanshi, Rabha, Garo and Lodha groups. On the contrary, this haplotype is probably absent in the high caste groups, Rarhi Brahmin and Vaidya, and is relatively infrequent in Jalia Kaibarta, a scheduled caste of the south-western part of the state. The Km1 allele is also high in frequency among Rajbanshi, Rabha, Garo and Munda in comparison with Rarhi Brahmin and Vaidya, suggesting the former four groups' strong Mongoloid affiliation. This survey signifies that there is considerable variation in the extent of Mongoloid admixture in Bengali populations. Such admixture is not restricted in specific social class either. It further demonstrates that heterogeneity of the genetic structure of Bengali populations do not correspond to the present social ranking on the basis of caste hierarchy.

Hemophilus influenzae type B disease in children vaccinated with type B polysaccharide vaccine

We studied 55 cases of invasive Hemophilus influenzae type b disease occurring in children at least three weeks after vaccination with type b polysaccharide vaccine. Their mean age at the time of immunization was 27.8 months (range, 18 to 47). Meningitis developed in 39 patients, of whom 3 died and 6 had neurologic sequelae. We investigated certain host factors that may have contributed to the failure of the vaccine. The geometric mean concentration of antibody to type b polysaccharide in convalescent-phase serum from 31 of the vaccinated patients who had hemophilus disease was significantly lower than that in serum from 25 patients of similar age with the disease who had never been vaccinated (0.59 vs. 3.46 micrograms per milliliter, P less than 0.001). However, only 3 of 46 patients in whom the vaccine failed and who were tested for hypogammaglobulinemia had this finding, and none of 33 children tested for IgG2 had low serum concentrations of this immunoglobulin subclass, which is thought to be important in the immune response to polysaccharide antigens. In addition, all but 1 of the 46 patients in whom the vaccine failed and who were tested for IgG antibody to tetanus toxoid protein, a thymic-dependent antigen, had normal values, and 19 of 20 tested for hemolytic complement activity had normal levels. In white children, the presence of the Gm immunoglobulin phenotype (1,2,3, 17; ;5,13,21) was associated with a sevenfold increase in the relative risk of vaccine failure (P less than 0.003). We conclude that vaccine failure may be related in part to genetic factors, and that most vaccinated children in whom Hemophilus influenzae disease develops have deficient antibody responses to the type b polysaccharide despite normal serum concentrations of immunoglobulin and normal antibody responses to tetanus toxoid.

Assessment of the potential pathogenicity of type II collagen autoantibodies in patients with rheumatoid arthritis. Evidence of restricted IgG3 subclass expression and activation of complement C5 to C5a

IgG subclass analysis by enzyme-linked immunosorbent assay of the autoantibody to native type II collagen, detected in 9 patients with classic or definite rheumatoid arthritis, demonstrated a predominance of IgG3 autoantibody. Gm allotyping revealed no obvious association with a particular phenotype. In comparative studies, IgG antibodies to the capsular polysaccharides of pneumococci and tetanus toxoid protein in these same patients consisted predominantly of IgG2 and IgG4. Purified type II collagen autoantibody from 3 of these patients activated complement C5 to C5a when bound to human cartilage in vitro, as measured by radioimmunoassay. These results represent direct evidence of a potential pathogenic role for this autoantibody in rheumatoid arthritis.

Correlation between deficiency of immunoglobulin subclass G3 and Gm allotype

Gm allotypes were investigated in 63 Swedes: 46 females and 17 males, in whom serum IgG3 was below 0.35 g/l. Both monoclonal antibodies and polyclonal antisera were used for the quantification. Concentrations of the other IgG subclasses were within the age-related normal ranges. The distribution of the IgG1 genetic markers G1m(a,x,f) differed markedly from that observed in normal Swedes (p less than 0.001). Thus G1m(a) was present in 60 subjects as compared to an expected 36, and phenotype G1m(-f) in 34 subjects as against an expected 8. The mean IgG3 concentration was numerically lower in the G1m(-f) group than in the G1m(+f) cohort, and individuals with IgG3 levels 0.10 g/l were more frequent in the G1m(-f) group. Among Caucasians, G3mg is in linkage disequilibrium with G1ma and our interpretations is that the haplotype G1ma;ax G2m-n G3mg is markedly increased in individuals with IgG3 deficiency.