HLA antigen frequencies in end-stage idiopathic and ischaemic cardiomyopathy.

We investigated the distribution of HLA antigens among 413 patients with ischaemic heart disease or dilated cardiomyopathy referred for cardiac transplantation to determine if possession of certain HLA antigens predisposed to end-stage heart failure. Of the patients studied, 234 had ischaemic heart disease (218 males), mean age 49 years (SD 7.1) and 179 patients had dilated cardiomyopathy (150 males), mean age 39 years (12.8). The control group comprised 2041 kidney donors reported to the United Kingdom Transplant Service between July and August 1985. We found a significant excess of HLA DR1 (odds ratio 1.64, 95% CI 1.16-2.33, attributable risk 5.0%) and DR5 antigens (odds ratio 1.47, 95% CI 0.99-2.18, attributable risk) among patients with dilated cardiomyopathy but not of HLA DR4 as previously reported. We found a lower frequency than expected of HLA B21 (10.44 expected, none observed) among patients with ischaemic heart disease but no other significant differences. This study provides some support for the concept of the risk of developing end-stage heart failure due to dilated cardiomyopathy being associated with possession of HLA DR1 and DR5, but no such evidence in ischaemic heart disease. Larger multi-centre studies are required to confirm the validity of these findings.

Difficulties in the ascertainment of C9 deficiency: lessons to be drawn from a compound heterozygote C9-deficient subject.

A group of patients with long-surviving mismatched kidney allografts were investigated for complement function using haemolytic assays in agarose gels. One patient was found to have no alternative pathway activity but a low normal classical pathway. Surprisingly, investigation revealed that the patient's complement was normal for all components except C9, which was functionally absent. The patient was shown to be heterozygous for DNA markers in the C6, C7 and C9 region of chromosome 5 and therefore appears to be a compound heterozygote for two uncharacterized C9 deficiency genes. Serological analysis by ELISA revealed that he has trace concentrations of a non-functional C9 molecule. Western blot analysis was not sufficiently sensitive to permit detection of this molecule. We hypothesize that the patient is heterozygous for a complete deficiency of C9 and for a gene directing hyposynthesis of a defective C9. We also suggest that C9 deficiency may be more common among Caucasians than has been reported.

Complement C6 and C7 DNA polymorphisms analysed by PCR in seven ethnic groups and characterisation of the C6 MspI RFLP.

Five polymorphisms in the C6 and C7 genes have been investigated in seven ethnic groups. The allele frequencies are broadly similar in most groups except C7 M/N which is monomorphic in our group of Africans, and C6 MspI and C7 S367T where the allele frequencies in African and Cape Coloured subjects are very different from the other ethnic groups. There is very little allelic association except between C6 A/B and C6 MspI. Seventeen of the 32 possible haplotypes have been observed, suggesting that much recombination has taken place. We describe a new method for the investigation of the MspI RFLP located in intron 3 of C6 (approximately 3 kbp 3' from exon 3 and 1.5 kbp 5' from exon 4) and its molecular basis, together with an improved method for the isolation of DNA from stored serum.

Complement component C7. Assessment of in vivo synthesis after liver transplantation reveals that hepatocytes do not synthesize the majority of human C7.

C7 M/N typing, the determination of the allotypes of the recently described C7 M/N protein polymorphism, was conducted on serum samples from donors and recipients of 100 liver transplantations to determine whether the liver is the predominant site of in vivo synthesis of human complement protein C7. Twenty-one cases were informative as the recipient was transplanted with the liver obtained from a donor with a different C7 M/N allotype. The determination of the C7 levels and phenotypes of up to 10 post-transplantation (p.t.) samples revealed that there was at most only a 50% contribution of the transplanted liver toward the C7 M/N allotype at 2 to 3 wk p.t.; that influence decreased with time and was approximately 10% in the samples obtained later than 6 wk after transplantation. C7 is thus the only terminal complement component not predominantly synthesized by hepatocytes, which is compatible with the observation that C7 is not an acute phase reactant. The transient contribution of the donor phenotype appears to be attributable to cells of the mononuclear phagocyte lineage, Kupffer cells in particular that are replaced by cells of recipient origin. Various cells of that lineage that are known to synthesize C7 in vitro, therefore, contribute more toward the C7 concentration than previously anticipated. Enhanced local C7 synthesis at the site of inflammation might add further to the basic C7 level especially because C7 is often the limiting factor for terminal complement complex generation.

Tissue typing, heart and heart-lung transplantation.

The effects of HLA matching and the presence of pre-existing anti-HLA antibodies, together with cross-match results, on heart and heart-lung transplants are discussed. Prospective HLA matching of donor and recipient is not usually performed for heart and heart-lung transplants. In a multi-centre study statistically significant improved survival with the better-matched heart grafts was found. In a small series of heart grafts it was also found that the improvement with HLA matching was confined to male recipients who were not blood group O. Heart graft recipients with wide panel reactive antibody had worse graft survival one year after transplant than the unsensitized. In several studies patients with a positive cross-match had a significantly lower survival rate than those with a negative cross-match. It is suggested that, minimally, pre-transplant screening and prospective cross-matching of highly sensitised patients is necessary.

Transfusion-associated graft-versus-host disease in patients with Hodgkin's disease and T cell lymphoma.

Two patients, one with Hodgkin's disease and one with peripheral T cell lymphoma, developed transfusion-associated graft-versus-host disease 16 and 8 days after transfusion of red cell and platelet concentrates. Fever and skin rash were followed rapidly by an elevation of liver enzymes and the onset of diarrhoea and pancytopenia. Despite treatment with high-dose methylprednisolone and anti-lymphocyte globulin, commenced within 7 and 2 days of the onset of rash, grade IV GvHD persisted and both patients died with severe pancytopenia. HLA types of peripheral lymphocytes of the patient with Hodgkin's disease were inconsistent with those of her parents and siblings, but HLA typing of her fibroblasts revealed that her true type was consistent with those of her parents and that her circulating lymphocytes were not genetically her own. The HLA types of the patient with T-cell lymphoma were inconsistent with those of her siblings which suggests, but, in the absence of other evidence, does not prove, chimaerism.

Graft-versus-host disease in solid organ transplantation.

Graft-versus-host disease is well recognized in bone marrow transplantation, but has only recently been described in solid organ transplantation. Two such cases in liver graft recipients, proven by the demonstration of donor type HLA antigens in the peripheral blood and marrow on tissue typing, are described in this paper. The literature on this subject is reviewed and the treatment discussed. It is postulated that there is an order of risk of development of graft-versus-host disease depending on the amount of viable lymphoid tissue included with the transplanted organ as follows: small bowel greater than heart-lung greater than liver greater than kidney greater than heart. It seems likely that this condition has been substantially underdiagnosed in the past and that greater awareness of the possibility of graft-versus-host disease in solid organ recipients will lead to the recognition of further cases and allow appropriate treatment to be promptly instituted.

Campath-1M--prophylactic use after kidney transplantation. A randomized controlled clinical trial.

Campath-1M is a rat monoclonal IgM antibody that binds human complement and recognizes virtually all peripheral human mononuclear cells. It is known to be effective in T cell depletion of bone marrow grafts, and encouraging results were obtained in a pilot study in which the antibody was used in prevention and treatment of rejection of kidney, pancreas, and liver allografts. In this randomized controlled clinical trial, Campath-1M has been evaluated as a prophylactic agent following renal allografting. It is shown that patients who received a 10-day course of the antibody immediately postoperatively, in addition to standard therapy with high-dose cyclosporine (17 mg/kg), experienced a significantly lower incidence of early acute cellular rejection than control patients who received cyclosporine alone. There was no evidence of "rebound" rejection following the end of antibody treatment to suggest that rejection had merely been delayed. However, patients who received this additional immunosuppression experienced a significantly higher incidence of serious infections than controls, this negating any benefit from the treatment in terms of graft survival. Thus, a monoclonal antibody of broad specificity directed against lymphocytes may be effective as a prophylactic agent after organ transplantation but its use should be accompanied by a reduction in other immunosuppressive drugs.

Lack of complementation between xeroderma pigmentosum complementation groups D and H.

The construction of permanent hybrid cell lines between xeroderma pigmentosum (XP) cells from different complementation groups allows analysis not only of the degree of repair correction but also of the restoration of biological activity to the UV-irradiated cells. With use of an immortal human cell line (HD2) that expresses excision repair defects typical of XP group D, a series of permanent hybrid cells has been produced with XP cells from groups A to H. Excision repair, as measured by incision analysis and unscheduled DNA synthesis, is restored to normal or near normal levels in crosses involving HD2 and cells from XP groups A, B, C, E, F, G, and I. All these hybrids show complementation for the recovery of normal UV resistance. As expected, hybrids expressing poor incision and hypersensitivity to UV were produced in crosses between HD2 and XPD fibroblasts, but they were also produced without exception when XPH was the partner. In the permanent HD2 x XPD or XPH hybrids, analysis of incision capacity reveals abnormally low activity and therefore that there has been no complementation. The true hybrid nature of HD2 x XPH cells has been confirmed by HL-A and -B tissue typing; moreover, detailed kinetic analysis of incision in these cells shows that the XPH phenotype, rather than the XPD, is expressed, i.e. breaks accumulate at low UV fluence of 1 J/m2. To help confirm these findings, another immortal XPD cell line was used in fusions involving HD2, XPH, or XPI. Cells resistant to ultraviolet were produced only with XPI fibroblasts. These data are discussed in terms of whether XPD and H mutations are likely to be allelic with respect to incision.

Definition of the HLA-Aw43 antigen.

The HLA antigen Aw43 has been observed only in Southern African populations. In order to confirm its identity and clarify its definition, ten cells with this specificity were shipped to laboratories in England, the United States of America and Australia to be tested with the sera from the 10th International Histocompatibility Workshop. The results of tests on nine of these cells which were sufficiently viable indicated that HLA-Aw43 is a distinct serological specificity which could be distinguished from both the A10 cross-reacting group (A25, A26 and Aw34) and A29. The Aw43 specificity segregated in two South African Negro families, and occurred commonly in association with Bw70. The occurrence of HLA-Aw43 in South African Caucasoids, in contrast to its absence in other Caucasoid groups, is probably due to genetic admixture with indigenous South African populations.

Definition of 15 equine leucocyte antigens.

Fifteen equine leucocyte antigens were defined by absorption and titration analysis of alloantisera obtained by natural sensitisation through pregnancy and by planned experimental immunisation. Definitive sera were tested on the cells of 90 unrelated horses and members of eight equine families. The family data suggested that 13 specificities were coded by a single locus (first locus) and one specificity (Eq 14) was coded by a second linked locus. The remaining specificity (Eq 7) was controlled by a third locus unlinked to the first or second loci. Tests on the cells of unrelated horses showed that two first locus specificities (Eq 16 and Eq 17) had a supertypic relationship to other first locus antigens. No individual was found to possess more than two first locus antigens, excluding the supertypic specificities.

Inherited structural variation and linkage relationships of C7.

Three structural forms of C7 have been distinguished by isoelectric focusing. They are the products of three co-dominantly expressed alleles at an autosomal locus. The C7 locus is close to that for C6, but is not close to the HLA complex.