HL-A heterozygosity as a genetic marker of long-term survival

Gender specific association of genetic variation in peroxisome proliferator-activated receptor (PPAR)γ-2 with longevity

Long-lived subjects have been shown to have peculiar anthropometric features (i.e. lower body mass index (BMI)) and metabolic parameters (i.e. improved insulin sensitivity). Life style and a genetic background potentially protective against the age-related metabolic derangement might contribute to such a particular phenotype. Peroxisome proliferator-activated receptor (PPAR)gamma-2 is an important regulator of adipose tissue metabolism, insulin sensitivity and inflammatory response. Thus, the potential role of genetic variability at Pro/Ala loci of PPARG gene on longevity was studied in 222 long-lived subjects and 250 aged subjects. We found a different Pro/Ala genotype frequency distribution between long-lived and aged men subjects, long-lived men having an increased frequency of Pro/Ala genotype (20 vs 8.5%); no differences was found when allele and genotype distribution of Pro/Ala gene polymorphism were analyzed in the two age group of women. Interestingly, subjects with Pro/Ala polymorphism had significantly lower BMI than Ala/Ala and Pro/Pro polymorphism. In conclusion, our study demonstrated that paraoxonase Pro/Ala gene polyporphism is associated with human longevity. Such an effect is probably due to the effect of Pro/Ala polymorphism on body composition and appears to be gender specific.

Immunogenetics of longevity. Is major histocompatibility complex polymorphism relevant to the control of human longevity? A review of literature data

Literature data suggest that human longevity may be directly correlated with optimal functioning of the immune system. Therefore, it is likely that one of the genetic determinants of longevity resides in those polymorphisms for the immune system genes that regulate immune responses. Accordingly, studies performed on mice have suggested that the Major Histocompatibility Complex (MHC), known to control a variety of immune functions, is associated with the life span of the strains. In the last 25 years, a fair number of cross-sectional studies that searched for the role of HLA (the human MHC) genes on human longevity by comparing HLA antigen frequencies between groups of young and elderly persons have been published, but conflicting findings have been obtained. In fact, the same HLA antigens are increased in some studies, decreased in others and unchanged in others. On the whole, that could lead us to hypothesize that the observed age-related differences in the frequency of HLA antigens are due to bias. In our opinion, this hypothesis is real for most studies owing to major methodological problems. However, some studies that do not meet these biases have shown an association between longevity and some HLA-DR alleles or HLA-B8,DR3 haplotype, known to be involved in the antigen non-specific control of immune response. Thus, HLA studies in man may be interpreted to support suggestions derived from the studies on congenic mice on MHC effects on longevity. However, in mice the association may be by way of susceptibility to lymphomas whereas, in human beings, the effect on longevity is likely, via infectious disease susceptibility. Longevity is associated with positive or negative selection of alleles (or haplotypes) that respectively confer resistance or susceptibility to disease(s), via peptide presentation or via antigen non-specific control of the immune response.

HLA, aging, and longevity: a critical reappraisal

Despite a large number of studies, available data do not allow at present to reach definitive and clear conclusions on role of HLA on longevity, owing to major methodological problems, such as serological and molecular typing of different loci, insufficient sample sizes, different inclusion criteria and age cut-off, inappropriate mixing of data referred to people from 58 to over 100 years of age, inappropriate control matching, and neglected consideration of sex-related effects and the different genetic make-up of studied populations. However, within this confused scenario, some data emerge. First, two studies that do not fit the biases above discussed show that some HLA alleles are associated with longevity. However, some of these alleles may confer an increased risk to undergo a variety of diseases. Second, longevity may be associated with an increased homozygosity at HLA loci. Third, an intriguing association between longevity and the 8.1 ancestral haplotype (AH), which has been proven to be associated with a variety of immune dysfunctions and autoimmune diseases, apparently emerges. This association appears to be a sex-specific (males) longevity contributor, and it is particularly interesting, taking into account that a type 2 (early infancy) --> type 1 (adulthood) --> type 2 (aging) shift of cytokine profile occurs lifelong, and that individuals bearing this haplotype show a type 2 immune responsiveness (note that type 1 cytokines mainly enhance cellular responses, whereas type 2 cytokines predominantly enhance humoral responses). On the whole, the (sex specific) association of longevity with alleles or haplotypes of several genes related to risk factors for a variety of diseases (cardiovascular diseases, cancer), including HLA alleles and haplotypes, is not unexpected on the basis of previous studies on the genetics of longevity in centenarians. This association can be interpreted under the perspective of a well known evolutionary theory of aging (antagonistic pleiotropy). This theory predicts that the same gene (or allele or haplotype) can have different roles (positive or negative) in different periods of the life span. Thus, the 8.1 AH should exert a positive effect during the infancy and aging but not in adulthood, when, indeed it is associated to susceptibility to a variety of diseases.

HLA and longevity or aging among Shanghai Chinese

Twenty-two centenarians and one hundred and seventy-nine nonagenarians (mean age 93 +/- 1.04 years) in the Shanghai Region of China were phenotyped for alleles of A (13 types), B (21 types) and C (6 types) loci of the human leukocyte antigen (HLA). The frequencies of HLA antigens were compared with 211 healthy adults whose ages ranged from 20 to 50 years. It was observed that A9 was highly associated with longevity (frequency in the longevity group is 38%, the control group 24%, P = 0.002). A30 showed marked inverse correlation (frequency in the longevity group is 8%, the control group 17%, P = 0.008). Cw3, Cw6 and Cw7 were also inversely correlated (P = 0.02, 0.04 and 0.02, respectively). Thus, it is likely that A9 may contribute to longevity while A30, Cw3, Cw6 and Cw7 may be associated with aging. The average superoxide dismutase (SOD) contents of erythrocytes in 48 cases with the HLA-A9 (without A30) antigen in the longevity group and in 13 cases with the HLA-A30 (without A9) antigen in the control group were 555 +/- 96 and 593 +/- 58 micrograms/gHb, respectively (t = 1.375, P > 0.05).

Elevated frequency of the C2 allele of the ETS-I oncogene in elderly subjects

We studied the frequency of an Sst I polymorphism of the ETS-I oncogene in 122 elderly subjects (mean age 78.14 years) and 115 teenagers (mean age 16.9 years). No difference in the frequency of the three genotypes (C1C1, C1C2, C2C2) was found between the two groups. However, the C2 allele occurred more frequently in the elderly subjects (chi 2 = 5.49, P < 0.02). These data suggest that the presence of the C2 allele may be associated with survival to old age.

Is the phenotypic combination A1B8Cw7DR3 a marker for male longevity?

OBJECTIVE

To study whether individual Human Leucocyte Antigens (HLA) at the HLA 1 or 11 loci or the phenotypic combination A1B8Cw7DR3 were associated with longevity.

DESIGN

Direct comparison of the > 90-year-old subjects with a control group.

SETTING

Northern Ireland population with little migratory mobility.

SUBJECTS

The > 90-year-old group (79 females, 38 males) was compared with a control group consisting of 150 unrelated blood donors (81 females, 69 males).

MEASUREMENTS

Human Leucocyte Antigen (HLA) Class 1 typing was carried out on 117 nonagenarians (mean age 93.7 years) and 150 younger controls (mean age 33.7 years) using conventional serological methods; HLA DR typing was carried out on 102 of the 117 > 90-year-old subjects, together with the 150 control subjects, and performed using restriction fragment length polymorphisms. The frequency of the phenotypic combination A1B8Cw7DR3 was measured in both groups.

RESULTS

There were no significant differences in the HLA antigen frequencies between the very elderly groups and the younger subjects at the A, B, C, and DR loci. The phenotypic combination A1B8Cw7DR3 was significantly increased (X3) in nonagenarian men compared with young men but not between elderly women and young women. There was a trend for increased representation of this phenotype in elderly men compared with women of the same age.

CONCLUSIONS

The frequency of the supratype A1B8Cw7DR3 was significantly increased in very elderly men but not in elderly women. Since this phenotypic combination has been associated with immune surveillance and/or hyperactivity in Caucasians, there is the suggestion that it could influence longevity through immune mechanisms but that sex differences may exist in its influence and expression.

Human major histocompatibility complex contains several leukemia susceptibility genes

In mice, homozygosity for the Mhc haplotype H-2k is associated with increased susceptibility to spontaneous and virus-induced leukemia, lymphoma and other neoplasms in the predisposed host. The influence of the Mhc on malignant development in these models is to shorten the latency after virus inoculation. Here, we present evidence that a similar phenomenon results in early-onset of human leukemia. A molecular analysis of the MHC in 112 CML patients showed that those who developed the disease when aged less than 35 years (early-onset group) had higher homozygosity rates for the DOA1, HSP70 and C4 alleles of the DR53 group of ancestral haplotypes, for a subtype of HLA-A3, and a higher allele frequency of BfFb compared to the late-onset group. The oldest patient (n = 13) homozygous for DR53 was 52-years-old (p = 0.004), and all HLA-A3 homozygous patients (n = 4) were in the early-onset group (p = 0.01). The relative risk for early-onset CML yielded by HLA-A3 homozygosity was 17.6. The well-known serological HLA-Cw4 association was not confirmed at the DNA level and thought to be due to linkage disequilibrium with BfFb. The factor B association was sex-limited. The DR52 group haplotypes appeared to be protective. The HLA-identical sibling frequency was increased only in the early-onset group (p < 0.01). Our findings agree with the concept of an MHC influence on the development of malignancies. The similarity in the location of the susceptibility loci and the serological cross-reaction between H-2Ek and DR53 raise the possibility that the mouse and human MHC share the same leukemia susceptibility genes.

Relation between skin cancer and HLA antigens in renal-transplant recipients

BACKGROUND

Recipients of renal allografts are at an increased risk for skin cancer. It is also known that recipients who are homozygous for HLA antigens are at an increased risk for certain cancers, as are those who are mismatched with their donors for these antigens. In a case-control study we assessed the relation between skin cancer in renal-transplant recipients and HLA homozygosity and mismatching.

METHODS

Of 764 patients who received renal transplants between 1966 and 1988, 66 had squamous-cell carcinoma or basal-cell carcinoma of the skin after transplantation. HLA homozygosity was assessed in all 66 recipients, and HLA mismatching in 39; the results were compared with those in 124 recipients without skin cancer. We also investigated the relation between skin cancer and the use of immunosuppressive drugs. In separate case-control analyses we investigated the influence of exposure to the sun and keratotic skin lesions on the risk of skin cancer.

RESULTS

The risk of squamous-cell carcinoma was increased in recipients mismatched for HLA-B antigens; the relative risks were 2.6 (95 percent confidence interval, 1.1 to 6.5) and 5.0 (95 percent confidence interval, 1.3 to 19.0) with mismatching for one and two antigens, respectively, as compared with no mismatching. Mismatching for HLA-A or HLA-DR antigens had no effect on the risk of squamous-cell carcinoma, and there was no association between mismatches at any of the HLA loci and the occurrence of basal-cell carcinoma. The total doses of azathioprine and prednisone were not associated with the occurrence of skin cancer or with HLA matching. Exposure to sunlight and keratotic skin lesions were strongly associated with skin cancer but not with HLA mismatching. Homozygosity for HLA-DR was more frequent among the patients with squamous-cell carcinoma (relative risk, 2.5; 95 percent confidence interval, 0.95 to 4.6) and among patients with 100 or more keratotic skin lesions (relative risk, 4.8; 95 percent confidence interval, 1.5 to 15.1).

CONCLUSIONS

HLA-B mismatching is significantly associated with the risk of squamous-cell carcinoma in renal-transplant recipients, as is HLA-DR homozygosity. An indirect effect on the level of immunosuppression does not appear to explain these findings, nor does exposure to sunlight or the number of keratotic skin lesions account for this observation.

Longevity and heredity in humans. Association with the human leucocyte antigen phenotype

Several arguments support the idea of a link between longevity and heredity, both in experimental animals and in the human species. In mice, genes in the major histocompatibility complex (MHC) are associated with a significant effect on life span. Results of analogous studies in man are confusing and contradictory. We have therefore investigated the question of an association of the human leucocyte antigen (HLA) and longevity in a large and ethnically homogeneous population. Our study population consisted of all 964 available inhabitants aged 85 years and over in the Dutch community of Leiden (pop. 104,000). Our control group comprised 2444 young inhabitants, aged 20-35 years, with an identical ethnic and demographic background. In addition, control groups of different age-brackets from the same region were used. Two antigens differed in frequency: HLA-B40 was lower and HLA-DR5 was higher in the group of 85 years and over, as compared to the control group, aged 20-35 years. Both differences were more evident in females. No major disease associations with HLA-B40 or HLA-DR5 have been reported. It is unlikely that these results are a chance observation: the overall similarity of the HLA pattern of the old and young age groups is a confirmation of their identical ethnic and demographic background and the changes as observed in the different age-groups were gradual. The biological meaning of these results is still unclear.

Influence of major histocompatibility complex region genes on human longevity among Okinawan-Japanese centenarians and nonagenarians

The frequencies of 80 HLA antigen phenotypes in 82 centenarians and 20 nonagenarians in Okinawa, Japan, were compared with those in other healthy adults in various age-brackets. Subjects aged over 90 had an extremely low frequency of HLA-DRw9 and an increased frequency of DR1. In this age-group the relative risk of corrected (for number of antigens) p value for HLA-DRw9 were 5.2 and 0.0001, respectively; those for HLA-DR1 were 13.3 and 0.0367, respectively. Since a high frequency of DRw9 and a low frequency of DR1 are associated with autoimmune or immune deficiency diseases, the genetic protection against these disorders may contribute to longevity.

HLA and T-lymphocyte function in old age

The role of the major histocompatibility complex in the genetic control of reactivity of peripheral blood mononuclear cells (T lymphocytes) to lectins and allogeneic cells as a function of age was investigated. In randomly selected aged subjects the frequencies of HLA-A, B, and some C locus alleles did not differ significantly from those in the control group. However, some tendencies of haplotype frequency differences between young and aged subjects were found. Significant associations of impaired or preserved T-lymphocyte function could be detected in connection with some HLA-A (A3, A11) antigens only. The tendency of some phenotypic HLA-A and B or C and B antigen associations to be in correlation with impaired or preserved T-lymphocyte reactivity in old age seemed to be independent of their age-related frequency differences. In family studies of a partially inbred Hungarian population, differences were found in the rate of diminution of allogeneic reactivity in groups sharing different HLA haplotypes. Based on statistical analysis of these data, a genetic factor segregating with the MHC and taking part in the regulation of the age-dependent decline of T-lymphocyte reactivity can be postulated.

Lack of association between HLA and age in an aging population

In a sample of 228 Framingham Study participants aged 58 to 86 who were typed for HLA, neither frequencies of individual antigens nor heterozygosity at the A or B loci appeared to be related to age. Previously found associations could be chance occurrences, or HLA-related effects on longevity in the general population might be small. It is also possible that such effects occur at younger ages than those included in our study or that HLA is related to the aging process in a way that is detectable only at very advanced ages.

Autoantibodies and immunoglobulin allotypes in healthy North American Blacks of different age groups

A population of 291 healthy North American Black subjects of different ages was studied for immunoglobulin (Ig) allotypes and the prevalence of autoantibodies, to determine possible associations between Ig allotypes and age, autoantibodies and age, and Ig allotypes and autoantibodies. Indirect immunofluorescence was used to detect anti-gastric parietal cell, anti-smooth muscle, anti-thyroid microsomal, anti-nuclear, and anti-mitochondrial antibodies. The sera were typed for the Ig allotypes Gm(1, 2, 3, 5, 6, 13, 14, 17, and 21) and Km(1) with a hemagglutination-inhibition assay. A significant association between advanced age and an increased prevalence of anti-nuclear antibodies was observed in females. There was no significant association between Ig allotypes and the autoantibodies tested. The results suggest that Ig allotypes are not involved in the development of autoantibodies in healthy Blacks.

HLA and longevity

One hundred fifty-five healthy nonagenarians, 45 men and 100 women, all French Caucasians, were phenotyped for alleles of the A, B, C, DR loci of the HLA complex. The observed HLA antigen frequencies were compared to those of a control series of 133 males and 179 females whose ages ranged from 10 to 50 years. When comparing the total young and elderly series, no significant differences were observed with respect to HLA antigen distribution or heterozygosity at any of the loci. When taking sex difference into account, however, an excess of the Cw1 antigen was found in the group of elderly females (p less than 0.001) and an excess of the Cw7 antigen in the group of elderly males (p less than 0.001). Of particular significance was the fact that Cw7 belonged in this instance to a phenotypic combination (and most probably to the corresponding haplotype) A1/Cw7/B8/DR3 which was found significantly increased in male nonagenarians (p less than 0.001). These results support the hypothesis that certain HLA haplotypes are associated with survival advantage.

Family analysis of Werner's syndrome: a survey of 42 Japanese families with a review of the literature

Forty-two Japanese families, including 80 individuals with Werner's syndrome were studied, confirming that this syndrome is inherited as an autosomal recessive trait. The incidence of malignancy was relatively high in these families and individuals with Werner's syndrome, although the incidence was not so high as was reported previously. HLA typing revealed no significant linkage with Werner's syndrome. The frequency of Werner's syndrome in Japan was estimated using two methods which indicated approximately 300 cases among 100 million people.

HLA and cancer in South African Indians

Two-hundred-and-forty-nine Indian cancer patients were tested for 39 HLA antigens and the antigen frequencies were compared with those of 603 control subjects. Comparisons were also made between cancer patients and controls for each ethnic group and for each site of cancer. There was an increase in the frequency of the HLA antigens A11 and Bw52 in patients with malignancies. Heterozygosity at the B locus was significantly increased in patients with cancer of the breast. The Aw24, B17 haplotype was also associated with breast cancer.

The evolution of an immune system

A model for the molecular evolution of an imune system is presented. It suggests how a system of cell surface-fixed antigen receptors, called FR, to be thought of as "primitive" but still functional antibodies, could evolve into the "modern" labile T cell and antibody system, the receptors for which may be called CER (clonal expansion receptors). Perhaps the most significant insight to be gained from the theory concerns the conclusion that the immune system of an embryo may be primed by the interaction between two types of cells with complementary surface specificities. In the first type of cell the interacting molecule is an FR molecule coded by a gene of the Major Histocompatibility Complex (MHC) which has undergone a somatic mutation; in the second type it is a CER molecule also coded by a gene which has undergone a recent somatic mutation. It is believed that this insight eliminates some of the problems experienced in understanding generation of diversity, and renders unnecessary some of the more complex hypotheses about immune networks. The mechanism of action of immune response genes is easily explained by the theory.

Increased HLA-B heterozygosity with age

427 healthy individuals ranging in age from 16 to 101 years were tested for HLA-A and -B antigens. No significant differences were found for any particular antigen according to the age of the individual. However, a significant trend of increasing frequency with age was found for individuals possessing two detectable HLA-B antigens. An apparent trend of increasing frequencies for individuals possessing four HLA-A and -B antigens was not significant. These results concur with those of some previously published studies.

HLA antigens and IgG allotypes on the Island of Barra (Outer Hebrides)

The distribution of HLA antigens and IgG allotypes in a group of nearly 200 adults on the Island of Barra, shows some unusual features. The sample tested included only people age 65 and over. Marked differences in the frequency of some HLA antigens were noted, compared to those previously determined for the northern island of Lewis and Harris, with increase in the frequency of HLA-A5 and B7. The latter antigen was present in over 40% of the group, compared with a frequency of 27% in the Northern islands. The high frequencies of HLA-A2, the Aw19 group and B12 previously noted in Scottish populations were also present. The IgG allotype, Gm (f;b4) was markedly increased, being present in 67% of the group, in comparison with frequencies of 40--45% in previous Scottish studies. These results either suggest a sampling phenomenon, or may be an indicator of selective forces related to immunological mechanisms or the age distribution of the population studied.

HLA-antigen frequencies in patients with a Plummer-Vinson stricture

Factors of individual susceptibility seem to be involved in the occurrence of Plummer-Vinson stricture, which is a permanent stricture of the cervical esophagus associated with long continued iron deficiency. Fifty female patients with Plummer-Vinson stricture were HLA typed and the antigen frequencies were compared with those of 75 female blood donors from the same geographic area and of the same race. A comparison was also made with the HLA antigen frequencies of a group of 200 blood donors (75 female and 125 male). There were no statistically significant differences in the HLA antigen distributions of the three groups.

An examination of HLA frequencies in three age groups

The question as to whether the distribution of HLA antigens differs between old and young persons has been studied only in a few population groups. There are observations showing an increase of heterozygosity of the HLA system (Bender et al. 1973, Gerkins et al. 1974) which indicate an advantage of heterozygosity for survival, but other studies fail to confirm this finding )Albert et al. 1974, Mucurová et al. 1975, Bender et al. 1976). Since the present authors, in a study of HLA gene frequencies on five small Danish islands (Hansen et al. 1974) had found a tendency to a changed frequency of certain HLA types among the oldest persons, it was decided to examine this question by typing larger numbers of persons of different age groups.

HLA antigens in different age groups

HLA typing was performed for 17 antigens on cells from 189 unrelated, normal white Caucasians. No significant differences (p greater than 0.05) in distributions of different markers were found among the age groups. There does not seem to be a relation between heterozygosity at HLA-A and HLA-B loci and survival until old age.

HLA and cancer in South African Negroes

Five hundred patients with cancer were tested for 32 HLA antigens and the antigen frequencies compared with those of 500 control subjects matched for race, sex and age. Although the overall frequencies showed no significant differences, detailed analysis with regard to site of cancer, age and the number of antigens detected at each locus revealed significant differences. Phenotype tables and haplotype frequencies have been included.

Immunologic considerations in renovascular hypertension

For decades certain diseases, such as glomerulonephritis, polyarteritis nodosa, scleroderma and serum sickness, have been linked with autoimmune pathogenesis. During recent years a host of additional diseases traditionally thought to have some genetic predisposition but with obscure etiology have been suspected of being autoimmune in nature. Rheumatoid arthritis, diabetes, myasthenia gravis and thyroiditis are diseases of widely divergent organ systems, yet may well have common pathways of pathology via immune complexing mechanisms. Herein we present evidence supporting the concept that renal artery stenosis (occurring primarily in association with the middle aortic syndrome or after renal transplantation) is of immune etiology. Although the specific antigenic agent is still to be defined there is growing acceptance of the theory that medium and large vessels are subject to autoimmune vasculitis in many aspects similar to the autoimmune affections of small vessels. Several cases are presented. Some of these suggest an immune reaction by the natural history but without evidence of immunochemical reactants in the involved vessels, presumably because active disease was arrested at the time of study. In other cases immunofluorescent preparations demonstrate reactants in the walls of the vessels to document the hypothesis more convincingly.

No indication of postnatal selection at the HL-A loci

When the HL--A allele frequency and the distribution of 2, 3 and 4 different antigens, respectively, in children and old people were compared no differences could be observed between the two groups. The data thus disprove a simple model by which HL--A heterozygosity should enhance surveillance.

The relationship between nasopharyngeal carcinoma and the HL-A system among Tunisians

Previous reports have demonstrated an association between the HL-A system and risk for nasopharyngeal carcinoma among the Chinese in Singapore. The present paper describes an investigation of HL-A profiles among NPC cases and non-NPC controls from Tunisia, to determine whether a similar association occurs in a different ethnic group. A total of 109 NPC cases and 84 controls were typed. At the second HL-A locus the results were similar to those found in Singapore, but the effect was less marked and did not reach high statistical significance. At the first HL-A locus, no association between A2 and NPC was found, in contrast to the Singapore results.