P. Platz

HLA-D and -DR antigens in genetic analysis of insulin dependent diabetes mellitus

SummaryThree groups of patients with insulin-dependent diabetes mellitus, ascertained by different procedures, were investigated for HLA-A, B, C and D antigens (n=164), and a subset (n=93) for HLA-DR. Both HLA-D/DR3 and D/DR4 were strongly positively associated and D/DR2 was negatively associated with insulin-dependent diabetes. HLA-DR4 was found to be a better marker for insulin-dependent diabetes than Dw4. The HLA-B associations (B8, B15 and B18) were clearly secondary to the increases of HLA-D/DR3 and D/DR 4. The HLA associations did not differ between familial and isolated cases indicating that these two groups may well have a common genetic background. Based on analysis of HLA-haplotype sharing in affected sibling pairs, a simple dominant model of inheritance could be ruled out, and a simple recessive model was found unlikely. The relative risks for the HLA-Dw3,4 and HLA-DR3,4 phenotype were 21.2 and 44.4 respectively and exceeded those of both the HLA-Dw3 and HLA-DR3 (5.6 and 4.3) as well as the HLA-Dw4 and DR4 (10.1 and 10.5) phenotypes. This argues against an intermediate genetic model but further studies are needed to clarify whether there is more than one susceptibility gene for insulin-dependent diabetes mellitus within the HLA-system.

Reconstitution in Severe Combined Immunodeficiency by Transplantation of Marrow from an Unrelated Donor

A patient with severe combined immunodeficiency received seven transplants of bone marrow from an HLA-B-compatible and HLA-D-compatible unrelated donor in an attempt to provide immunologic reconstitution. The first four transplants achieved restricted engraftment with evidence of rudimentary immunologic function. A fifth transplant, given after low-dose cyclophosphamide, produced reconstituion of cell-mediated immunity. Marrow aplasia developed after recontamination with a nonpathogenic microflora. Transplantation of marrow previously stored in liquid nitrogen was ineffective. A subsequent transplant, administered after high-dose cyclophosphamide, achieved durable engraftment, with complete hematopoietic and immunologic reconstitution. Seventeen months after transplantation, full functional engraftment persists. Graft-versus-host disease has been chronic and moderately severe, but limited to the skin and oral mucosa. Transplantation of marrow from unrelated histocompatible donors may provide a useful treatment for patients with severe combined immunodeficiency or aplastic anemia who lack a matched sibling or related donor.

RECIPIENT LYMPHOCYTE SENSITIVITY TO METHYLPREDNISOLONE AFFECTS CADAVER KIDNEY GRAFT SURVIVAL

In 42 recipients of mixed-lymphocyte-culture (MLC) incompatible cadaver kidneys and conventional immunosuppressive treatment (azathioprine and steroids) the concentrations of methylprednisolone suppressing the in-vitro response of pretransplant lymphocytes to phytohaemagglutinin by 50% (ED50) were determined. 1-year graft survival was significantly higher in 21 recipients with methylprednisolone ED50 values below the median than in 21 patients with higher than median ED50s (86% v 29%; p less than 0.0002). Thus, the steroid sensitivity of recipients strongly influences the survival of MLC-mismatched kidneys. In 42 transplant recipients treated with cyclosporin and steroids, the effect of steroid sensitivity was also apparent (1-year graft survival 76% and 57% for recipients with low and high ED50, respectively), though not significant. Determination of the sensitivity to steroids may be valuable in determining which recipients can be given HLA-DR-mismatched kidneys and may serve as a guideline for determining the dose of steroids to be used.

Studies of the HLA System and Insulin-dependent Diabetes Mellitus

The relationship between the HLA system and insulin-dependent diabetes mellitus (IDDM) is reviewed. Data compiled by the HLA and Disease Registry reveal that HLA-B8 and/or Dw3 are associated with IDDM in all populations studied so far, but further population studies in non-Caucasian populations should be performed. In Caucasians, HLA-Dw2 renders protection against IDDM while HLA-Dw3 and Dw4 are associated with susceptibility to IDDM. The exact mode of inheritance of susceptibility to IDDM remains to be established. Involvement of at least two genes is likely. Heterogeneity of IDDM is highly possible and should be a matter of major interest in diabetes research.

NcoI restriction fragment length polymorphism (RFLP) of the tumour necrosis factor (TNF alpha) region in primary biliary cirrhosis and in healthy Danes

The restriction fragment length polymorphism of the human tumour necrosis factor (TNFα) region was investigated by means of 20 different restriction enzymes and a human TNFα cDNA probe. Only one of the enzymes, NcoI, revealed a polymorphic pattern consisting of fragments of 10.5 and 5.5 kb, which behaved as alleles. In a panel of 108 random, healthy, unrelated Danes, the phenotype frequencies of the 10.5 and 5.5 kb bands were 0.94 and 0.53 and the gene frequencies were 0.71 and 0.29, respectively. The test for Hardy‐Weinberg equilibrium showed no significant deviation from the expected values. The 5.5 kb band was strongly positively associated with HLA‐DR3, HLA‐B8, and HLA‐A1. In 22 patients with primary biliary cirrhosis a significantly (corrected P= 0.024) decreased frequency of the 10.5 kb fragment was found. Additional studies are in progress to substantiate this association.

T-cell subset alterations and lymphocyte responsiveness to mitogens and antigen during severe primary infection with HIV: a case series of seven consecutive HIV seroconverters.

Seven consecutive patients who presented with a severe acute mononucleosis-like illness associated with HIV seroconversion were evaluated by T-cell subset enumerations and measurements of lymphocyte transformation responses to mitogens and antigen during both their primary illness and a 1-year follow-up period. We observed a characteristic pattern of response to primary HIV infection; initial lymphopenia was followed by CD8 lymphocytosis and inversion of the CD4:CD8 ratio. During follow-up, the CD8 count gradually returned to normal, whereas the CD4:CD8 ratio remained inverted because of a relatively low number of CD4 lymphocytes. Primary infection was followed by prolonged and severe cellular hyporesponsiveness to both mitogens and antigen. At the last follow-up, responses to pokeweed mitogen were still severely impaired, with a median 19% (range 7-50%) of that observed in healthy controls. We conclude that severe primary HIV infection may be followed by sustained lymphocyte hyporesponsiveness, a sustained low percentage of CD4 lymphocytes and sustained inversion of the CD4:CD8 ratio.

HLA, Autoimmunity and Insulin-Dependent Diabetes Mellitus

The etiology and pathogenesis of juvenile diabetes mellitus (JDM), i. e., in sulin-dependent diabetes in nonobese individuals, are still poorly understood.

HLA and heterogeneity of multiple sclerosis

Age at onset, debut symptoms, optic nerve signs, and severity of symptoms were evaluated from the medical records of 135 patients with MS. HLA-D/DR2 was significantly more frequent in rapidly progressive MS, and D/DR2 seemed to confer both susceptibility to the disease and to more rapid progression. However, D/DR3 seemed to protect against rapid progression.

Immunological studies in acquired immunodeficiency syndrome. Functional studies of lymphocyte subpopulations.

The lymphocyte transformation response in vitro to mitogens (phytohaemagglutinin, concanavalin A, and pokeweed mitogon) and antigens (purified protein derivative and tetanus) was studied in three patients with acquired immunodeficiency syndrome (AIDS), three patients with pre‐AIDS. and six healthy controls before and after depletion of T4‐ or T8‐positive cells. In controls, TS‐depleted lymphocytes responded as well as peripheral blood mononuclear cells (PBMC) when monocytes were added, whereas T4‐depleted cells gave about 50% of this response to mitogens and no response at all to antigens. No evidence of suppression was seen when various mixtures of T4‐ and T8‐depleted cells were made. In particular, there was a virlually linear relationship between the percentage of T8‐depleted cells and the response to antigens. The PBMC of all AIDS and pre‐AIDS patients had very low or absent responses to mitogens and antigens, and except in one case, this response did not increase after depletion of T8‐positive cells (and addition of monocytes), indicating that these patient cells also lack suppressor activity in this assay. However, a significantly increased response to mitogens was seen when the TS‐depleteu suspensions were adjusted to contain 20,(HK) T4‐positive cells per well, but the response was still significantly lower than that of similar suspensions from controls. Thus, not only are the poor responses of PBMC from AIDS and pre‐AIDS patients due to a low concentration of T4‐positivc cells, but the responsiveness of these cells also seems deficient. Furthermore. TS‐positive patient cells also have an impaired responsiveness. Our experiments do not exclude the possibility that the low response is due to a T8‐negative suppressor cell, but it seems more likely that both the T4‐ and the T8‐positive cells are deficient and/or that there is a deficiency in accessory cells. These possibilities are currently under study.

Investigation of immunosuppressive properties of inactivated human immunodeficiency virus and possible neutralization of this effect by some patient sera

Retroviral infections are accompanied by immunosuppression in a variety of species. For feline leukemia virus, the immunosuppression has been ascribed to the transmembrane envelope protein, p15E, which suppresses the proliferative responses of cat, mouse, and human lymphocytes. A similar suppressive effect has been shown for a lysate of human immunodeficiency virus (HIV), strain HTLV-IIIB. Here we determined that detergent-disrupted HTLV-IIIB lystate exerted a strong suppressive effect on PHA-stimulated lymphocytes. Preparations of whole virions, a lysate of a local HIV isolate grown on MP-6 cells, and a commercially obtained UV and psoralene-inactivated lysate were examined and demonstrated to have a similar suppressive effect. The HIV lysate was not directly cytotoxic to lymphocytes and did not contain tumor necrosis factor or lymphotoxin. The HIV lysate specifically suppressed the proliferation of a range of hemopoietic cell lines from man and mouse including three EBV transformed CD4- and IL-2 receptor-negative B-cell lines. The lysate also suppressed the formation of human bone marrow colonies, whereas the lysate had only a slight or no effect on fibroblasts. The suppression of lymphocyte proliferation was not abrogated by addition of IL-2 or IL-1 and the HIV lysate inhibited the expression of IL-2 receptors on suboptimal PHA-stimulated mononuclear cells. The suppressive factor(s) has not been characterized in molecular terms, but suppressive activity was recovered in fractions with a molecular weight of about 67,000 and in both the glycoprotein fraction and in the glycoprotein-depleted fraction of the HIV lysate. Sera from one-third of a small series (N = 13) of individuals with antibodies to HIV seem to be able to neutralize the suppressive properties of HIV lysate in cultures.