Comparison of the HL-A phenotypes of lymphocytes and kidney cells determined by the fluorochromasia cytotoxicity assay.

Correlation of leukocyte typing with homograft survival suggests that HL-A typing of white blood cells reflects the histocompatibility factors of the kidney, yet some apparently well-matched kidneys are rejected. The latter results may, in part, reflect inadequacies of typing techniques, incomplete expression of HL-A factors on white blood cells as compared with the cells of the rejected organ, or isoantigens not shared with leukocytes. In this study the kidney cells and lymphocytes (from blood or nodes) of 14 individuals were typed for HL-A factors 1, 2, 3, 5, 7, 8, 9, and 12, and factors 4a and 4b by fluorochromasia cytotoxicity. Biopsied kidney cells were prepared with 0.25% trypsin and typed fresh, after varying periods in monolayer culture or after storage in liquid nitrogen, in all cases resulting in cells which were pleomorphic but uniform in reactivity. Reproducibility of lymphocyte typing was 99%, and of kidney cell typing, 93%. The 4a factor was detected on the lymphocytes but not the kidney cells of four individuals. HL-A7 and HL-A8, in contrast, were detected on kidney cells and not lymphocytes of four and three individuals, respectively. Results were consistent within the groups of individual sera used to detect each factor. The HL-A factors detected on both kidney cells and lymphocytes never resulted in more than two alleles at each genetic sublocus. Several examples of post-rejection sera have reacted with donor kidney cells but not with lymphocytes. Kidney cells may thus be useful in compatibility tests to aid in selection of donors for a retransplant. The ability to store donor kidneys by perfusion provides time to employ kidney cells for typing and in compatibility tests, and the use of a standard cytotoxic assay makes their routine use practical. Typing kidney cells as well as lymphocytes thus offers an approach to more complete and accurate HL-A phenotyping.

Heterosexual transmission of human immunodeficiency virus type 1 from transfusion recipients to their sex partners.

Using lookback procedures and other methods, we identified and then prospectively followed human immunodeficiency virus type 1 (HIV-1)-infected transfusion recipients and their sex partners to determine AIDS incidence and risks of heterosexual transmission of HIV-1. At enrollment, 7 of 32 (21.9%) female partners of male recipients were themselves infected with HIV-1, as compared with none of 14 male partners of female recipients (p = 0.08). No additional episodes of transmission were observed. The prevalence of advanced immunodeficiency at enrollment was similar in male and female recipients. Male recipients with advanced immunodeficiency (CD4+ lymphocyte count < or = 0.20 x 10(9)/L or a history of clinical AIDS) at enrollment were more likely to have infected their female partners (odds ratio = 7.9; p = 0.03) than men with neither condition. Similarly, AIDS-free survival, as estimated by the product-limit method, was lower among male transmitters than among male nontransmitters (p = 0.01). Transmission was not associated with frequency of unprotected vaginal intercourse. Our data suggest that HIV-1-infected men who develop immunodeficiency rapidly are more likely to infect their sex partners and that the greater efficiency of male-to-female HIV-1 transmission is not explained by a greater number of sexual contacts or more advanced immunodeficiency in index subjects.

Renal allograft failure and cold red blood cell autoagglutinins.

Ten patients in a retrospective review of 250 kidney transplant recipients had RBC-cold agglutinins reactive at 22 C. Fourteen transplants were performed in those 10 patients. Five of nine cold renal allografts failed to function. Two of these recipients later had successful transplants when the kidneys were warmed before reestablishment of blood flow. Three other patients with cold RBC autoagglutinins had immediate renal function when the transplanted kidneys were warmed. In a prospective study of 126 patients, 59% had cold RBC agglutinins at 4 C and 11% were alos reactive at 22 C. Red blood cell-cold autoagglutinins appear to be a preventable cause of acute renal allograft failure. The titer and thermal amplitude of these antibodies are probably of major importance and should always be determined before organ transplantation.

A simple enzyme-immunoassay (EIA) test for factor VIII-related antigen (VIIIAGN).

An enzyme immunoassay (EIA) system has been developed to measure factor VIII-related antigen (VIIIAGN). This assay gives similar results to the commonly used Laurell electroimmunodiffusion (EID) assay for VIIIAGN as shown by comparison of both techniques with samples from healthy controls, patients with hemophilia A, and patients with von Willebrand's disease. The assay also has a greater precision than the EID technique as demonstrated by multiple assays of aliquots of a single sample. The use of this EIA test for VIIIAGN is simple and employs inexpensive reagents and equipment. The use of expensive antisera is minimized. EIA for VIIIAGN has the advantage of increased sensitivity compared to Laurell EIA.

Bovine plasma as a reference standard for the factor VIII assay.

Definition of one unit of factor VIII procoagulant activity may be imprecise, for a number of reasons. Levels in individual normal plasmas differ sufficiently that small pools do not have equivalent activities. Large pools cannot be prepared without loss of activity because of the lability of factor VIII. Human factor VIII may not be stable at --20 C. Lyophilized standards may vary in activity because of difficulties in dissolving the materials. The authors have prepared standards that are stable at --20 C for years using beef plasma diluted in outdated human blood bank plasma. The level of activity of this working standard is verified by repeated assays of lyophilized national standards and of small pools of normal donor plasma. The standard is equally applicable to one- or two-stage assays for factor VIII.

Problems in paternity testing. Subtypes of AB.

Paternity test results demonstrated that a child of type A1 has a mother who types as an A2B; the putative father is type O. According to the recent AMA-ABA joint report, these results prove nonpaternity. All other erythrocytic and HLA typing indicated a high probability that the putative father was the biologic father. Since the expression of the A1 gene may be weakened on the erythrocytes of a type AB person, the possibility that the mother carried an A1 gene was considered. Review of published data reveals that in black persons there appears to be an excess of type A2B and a deficiency of type A1B compared with the numbers expected from gene frequencies. It is possible that as many as one of five black persons with A1 and B genes has an A2B phenotype.

Re-evaluation of plasmas from patients previously diagnosed as having von Willebrand's disease with the factor VIII-related antigen and ristocetin cofactor assay.

Diagnosis of deficiencies of coagulation factor VIII can be difficult to establish in some cases. The use of the factor VIII-related antigen and the use of the ristocetin cofactor assays have increased the reliability of diagnosis of factor VIII deficiency in patients with hemophilia A or von Willebrand's disease, and in carriers of hemophilia A. The authors re-evaluated samples, from frozen storage, of blood from patients previously diagnosed as having von Willebrand's disease. This diagnosis was based on clinical history, family history, bleeding time, factor VIII procoagulant activity, and response to ristocetin in platelet-aggregation studies. Eleven cases were studied by the review of previously obtained data and the addition of the factor VIII-related antigen and ristocetin-cofactor assays. In two of eleven cases, the diagnosis was changed to possible hemophilia A carrier state.

The influence of presensitization on graft survival rate.

Graft survival rate was evaluated in 61 recipients with greater than 50 percent frequency of performed antibodies to selected panel cells. This includes recipients of primary cadaver grafts, secondary cadaver grafts, and living related grafts. Graft survival rate also was evaluated in 199 recipients with pretransplant antibodies reacting with 10 to 50 percent of panel cells and in nonsensitized patients. The results show that good graft survival can be obtained in many hyperimmunized patients, particularly in recipients of primary renal allografts (66 percent cadaver graft survival rate at 2 years). However, sensitization following rejection of an allograft appears to confer a less favorable prognosis. The nature of recipient presensitization and the precise specificity of each reactivity cannot always be explained. This is exemplified in three patients in whom broadly reactive lymphocytotoxic antibodies were not directed against HL-A antigens. Since the number of sensitized patients who await renal transplantation is increasing, there should be no hesitation in proceeding with transplantation, particularly with primary grafts. Emphasis, however, must be placed on frequent prospective recipient serum sampling so that transient high levels of cytotoxins do not escape detection and therefore can be easily selected out for cross-matching against potential donors.

Graft survival with high levels of cytotoxic antibodies.

In this study, pretransplant transfusions significantly improved the survival of first cadaver kidney transplants. Large numbers of transfusions had the same influence on graft survival as small number of transfusions. Graft survival was not influenced by pretransplant antibody levels, and the beneficial effect of transfusions was also independent of highest pretransplant antibody levels. The positive relationship between transfusions and cytotoxic antibodies was shown to be highly significant. B-warm and T-warm antibodies were both increased by transfusions and tended to occur together. B-cold antibodies occurred independent of transfusions, B-warm and T-warm antibodies. The results of this study suggest, but do not confirm, that B-cold antibodies benefit graft survival, while T-warm antibodies adversely influence graft survival. Transfusions and B-cold antibodies appear to influence graft survival by different mechanisms.

HLA typing and primary cadaver graft survival.

Analysis of 463 consecutive primary cadaver renal transplants showed no influence of HLA match grade on renal allograft survival. Additional categorization according to HLA match grade and degree of presensitization again showed no correlation between match grade and graft survival. Mismatches and matches of specific antigens, cross-reacting groups of antigens, and effect of matching at both locus A and B were also evaluated. There was no significant effect on graft survival except when mismatches against donor A2 and cross-reacting group A2, A28 occurred. A trend toward better graft survival was suggested in recipients matched for A9 and cross-reacting group A9, Aw 23, Aw 24. Although HLA match grade did not influence ultimate graft survival, HLA typing remains important, especially to avoid mismatch against donor A2 antigen. In addition, subsequent detection of new specificities, particularly in other than the A and B loci, may provide significance in the future.