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Biomedical subjects

K K Mittal

Publications and source records attributed to K K Mittal.

At least 73 records · Page 4Linked to original sources

The merrit alloantigenic system of human B lymphocytes: evidence for thirteen possible factors including one six-member segregant series.

An analysis of the typing results of a 70-member chronic lymphatic leukemia B cell panel revealed evidence for 13 possible groups of the Merrit alloantigenic system. Six of these appeared possibly allelic and may represent a segregant series. The CLL panel was also fully typed for HLA and some degree of linkage dysequilibrium between Merrit and HLA seemed apparent from the data. Merrit antibodies can be absorbed out with selected surface membrane immunoglobulin (SMIG)-positive normal lymphocytes and less so or not at all with E rosette-forming T cells or Fc-positive SMIG-negative lymphocytes.

Absorption↗

Matching of histocompatibility (HL-A) antigens for platelet transfusion.

The average in vivo platelet survival was measured by both per cent recoveries (%R) and half-lives (t 1/2) of 51Cr-labeled platelets in 69 transfusions given to 43 thrombacytopenic patients. The results demonstrated that (1) increase in the number of HL-A incompatibilities in the platelet donor was significantly associated with decreased %R and t 1/2 of the infused platelets; (2) survival of transfused platelets from HL-A-matched single donors was consistently superior to those pooled from several grossly mismatched donors; and (3) survival of platelets infused when patients had circulating lymphocytotoxic antibodies was consistently lower than when patients did not have such antibodies, regardless of whether it was the first, second, or third such infusion.

ABO Blood-Group System↗

Donor HL-A incompatibility and lymphocytotoxic antibody response in human renal allotransplantation.

When 81 recipients of primary renal allografts were examined for the influence of donor HL-A incompatibilities (DIC) on the survival of allografts, an association was found between greater DIC and not only an increased loss of allografts in the 1st year, but also a decreased survival of transplants in the subsequent years. However, three allografts with no DIC were rejected, whereas nine others with three to four imcompatibilities have functioned well for 1-5 years. A surprisingly high proportion (52%) of 81 renal allograft recipients produced lymphocytotoxic antibodies which lack HL-A specificity but apparently detect a polymorphic antigenic system on normal human lymphocytes. Only three patients who rejected the allografts made detectable circulating antibodies specific to DIC. However, when patients received grafts with fewer DIC, there was a greater number of no antibody or low frequency antibody producers, whereas with a greater number of DIC there was an increased occurrence of high frequency antibody producers. These results suggest that HL-A as well as non-HL-A systems may play a significant role in the success of allotransplantation. Although the presence of non-HL-A antibodies was not always associated with allograft loss, further characterization of these antibodies may reveal a new genetic system(s).

Antibody Specificity↗

The HL-A and ABO antigens in trophoblastic disease.

No statistically significant deviations in phenotype frequencies of the 25 HL-A antigens or the ABO antigens were seen when 111 Caucasian patients with trophoblastic disease were compared with 1,259 healthy Caucasian controls. However, an increasein the incidence of HL-A11 was found in 39 patients who currently had the disease, but not in 72 who had recovered from the disease. Further, an increase in the frequency of W18 was observed among 18 patients who currently had 'invasive' disease (choriocarcinoma or invasive mole), but not in 44 who had recovered from such disease. If valid for larger patient population, these increases may suggest association of HL-A11 and W18 with the 'morbidity' of the trophoblastic disease. No increase in histocompatibility was seen in 45 patient-couples over 67 control-couples in terms of decrease in the number of male spouse's HL-A incompatibilities, and no significant difference was seen in the distribution of pregnancies in the two groups. No significant difference was observed in the incidence of different male-female combinations of ABO blood groups between 95 patient-couples and an equal number of control-couples. Lymphocytotoxic antibodies were found in 64 patients (158 sera) or 36% of the 178 patients (413 sera) examined. HL-A specific antibodies were found in 30 or 17% patients (39 sera). Of these 30, 24 patients had molar pregnancies and six had choriocarcinoma. Whether these antibodies have a role in the destruction of neoplastic tissue remains to be determined.

ABO Blood-Group System↗

Cross-reactivity of monospecific anti-HL-A antisera.

32 'monospecific' anti-HL-A alloantisera were absorbed in separate tests with platelets from a maximum of 56 different persons and examined for residual cytotoxicity against target lymphocytes from one or two unrelated persons having the homologous (or test) antigen. Of the 799 combinations in which platelts had the test antigen, 715 (90%) were specifically inhibited; of the 720 combinations in which platelets had the cross-reactive antigen(s) (but not the test antigen), 417 (58%) were specifically cross-inhibited; and of the 1,839 combinations in which platelets had neither the homologous nor a discernable cross-reactive antigen, 133 (7%) were cross-inhibited 'nonspecifically'. Earlier findings of cross-reactivity were confirmed, and results suggested that HL-A1, HL-A10 and W30 on platelets may cross-inhibit anti-HL-A2 antibodies; HL-A7 and W21 may cross-inhibit anti-HL-A5 and anti-W5 antibodies; W16 may cross-inhibit anti-HL-A5 antibodies; and W22 may cross-inhibit anti-HL-A13 antibodies.

Antibody Specificity↗

Human histocompatibility (HL-A) antigens in semen and their role in reproduction.

Seminal plasma from 7 of 10 normal persons was found to inhibit anti-HL-A2, 3, 7, 8, and 12 antisera specifically. Inhibition by seminal plasma appeared quantitatively less than that by whole serum and even less than that by platelets from the same individuals. No decrease in the number of offspring was found due to increased numbers of HL-A incompatibilities of the male spouse in 67 normal couples. No clear decrease in the number of pregnancies was observed in normal women with lymphocytotoxic antibodies. A similar study with infertile persons may yet reveal a role for HL-A antigens in human reproduction.

ABO Blood-Group System↗

Single donor, HL-A matched platelet transfusions for thrombocytopenic patients undergoing surgery.

Thrombocytopenic patients, who displayed hemostatic disorders and had been previously sensitized by repeated blood transfusions and/or pregnancies, were supported for surgical procedures by platelet transfusions obtained from a single ABO and HL-A matched donor by the use of continuous collection centrifugation. Because of the low incidence of HL-A identical donors, compatibility was assessed by known serological cross-reactivity of the HL-A determinants. In three cases repeated platelet transfusions had excellent in vivo survival, and sensitization could not be detected by a battery of immunological assays. In one case there was immune sensitization and refractoriness to repeated platelet transfusion, as documented by accelerated in vivo destruction of donor and third-party platelets bearing the disparate factor HL-A8. Although serologic tests for lymphocytotoxic and leukoagglutinating antibodies were negative, the patient displayed cellular immunity in leukocyte aggregation and cell-mediated plateletolysis tests. The single donor, continuous collection technique appears to have the technical advantage of rapid, efficient collection and the immunological benefit of a restricted spectrum of allosensitization.

ABO Blood-Group System↗