HLA-DQA1*0505 sharing and killer immunoglobulin-like receptors in sub fertile couples: report from the 15th International Histocompatibility Workshop.

This aim of the study was to investigate whether human leukocyte antigen (HLA)-DQA1*0505 sharing or the maternal killer immunoglobulin-like receptor (KIR) repertoire is associated with recurrent spontaneous abortion (RSA) or repeated implantation failure (RIF). The study included 224 couples with RSA, 61 couples with RIF, 182 fertile couples, and 10 couples with successful in vitro fertilization and embryo transfer (IVF)/ET at first cycle. HLA-DQA1*0505 typing using polymerase chain reaction-sequence-specific oligonucleotide (PCR-SSO) was performed in 185 RSA (117 with alloimmune abnormalities and 68 of autoimmune etiology), 61 RIF and 182 control couples, and KIR genotyping using polymerase chain reaction-sequence-specific primer (PCR-SSP) in 167 RSA and 55 RIF cases as well as 46 RSA and 10 IVF controls. No differences in DQA1*0505 sharing were found between patients and controls. In RSA and RIF women, the ratio of inhibitory to activating KIRs was slightly lower (1.53 and 1.85 vs 2.03 in controls). The analysis of maternal inhKIR and fetal HLA-C molecule pairs showed that the 'less inhibiting' combination KIR2DL3-C1 was found in higher percentage in subfertile (mainly RIF) than in fertile couples. In contrast, the percentage of cases possessing the 'strong inhibiting' combination KIR2DL1-C2 was lower in the RSA and RIF groups in comparison with that in the control groups (17.36% vs 23.91 and 16.36% vs 40%, respectively). In women with >or= 6 implantation failures, the KIR2DL1-C2 combination was not found in any of them (P = 0.0014), and the KIR2DL3-C1 combination was not found in the control IVF group. The results oppose the suggestion that increased HLA-DQA1*0505 sharing predispose to RSA or RIF. The KIR2DL3-C1 combination (or lack of the KIR2DL1-C2 one) is associated with implantation failure.

14th International HLA and Immunogenetics Workshop: report from the reproductive immunology component.

The aim of the study was to investigate whether human leukocyte antigen (HLA) allele sharing between partners or the maternal killer immunoglobulin-like receptor (KIR) repertoire is associated with recurrent spontaneous abortion (RSA) and repeated implantation failure after in vitro fertilization (IVF)/embryo transfer. From a total population of 158 RSA couples, 40 couples with repeated implantation failures (IVF) and 81 control couples, reported by five different laboratories, analysis was performed for (a) HLA sharing in 50 RSA, 31 IVF and 31 control couples, (b) DQA1*0505 sharing/homozygosity among partners in 108 RSA, 40 IVF and 36 control couples, and (c) the women's KIR repertoire in 46 RSA, 26 IVF and 36 control wives. RSA couples were divided into alloimmune aborter (RSAallo) and autoimmune aborter (RSAauto). The results oppose to the suggestion that increased HLA sharing per se or a limited maternal KIR repertoire predisposes to RSA or IVF failure. However, the observation of a slightly higher percentage of DQA1*0505 sharing in the RSAauto and the IVF group needs further investigation. The ratio of inhibitory to activating KIR (actKIR) was slightly lower in RSAallo and IVF women (1.9 vs 2.6 in controls), while in a high percentage of these women, the standard receptors of the KIR A haplotype were combined with actKIR/s of the haplotype B (66.6% and 45.4% vs 20% and 15.3% in RSAauto and control groups). This may suggest a possible involvement of actKIRs in embryo implantation and the maintenance of pregnancy and also requires further investigation.

The significance of the women's repertoire of natural killer cell receptors in the maintenance of pregnancy.

Large numbers of decidual natural killer (dNK) cells are in direct contact with the invading trophoblast and are considered to be important for pregnancy, since they can produce cytokines and other mediators involved in the control of trophoblast invasion, trophoblast differentiation, decidual artery remodeling and placental augmentation. The dNK cells are also the main candidate cells to attack trophoblast in cases of alloimmune abortions, where the fetus is 'rejected' by the pregnant woman. The function of NK cells is regulated by a balance between activating and inhibitory signals provided by their heterocladic receptor repertoire upon recognition of specific ligands, most of which are HLA molecules (HLA-C, HLA-G, HLA-E) expressed on invading trophoblast. It is a challenge to investigate abortions in regard to the receptors that dNK cells bear and the MHC molecules that the trophoblast expresses. Our studies in couples with recurrent spontaneous abortion as well as in random cases of abortion revealed that aborting women usually have a limited repertoire of inhibitory receptors of the KIR family (inhKIR), and that many of them lack inhKIRs specific for the fetal HLA-Cw antigens. We suggest that some spontaneous abortions are caused because of a limited maternal inhKIR repertoire and a lack of maternal inhKIR-fetal HLA-C epitope matching. Among the different interactions of NK receptors with their specific counterparts on trophoblast, the inhKIR-HLA-C interactions appear to be those mainly involved in the function of an NK cell-mediated allorecognition system in pregnancy.

Lack of the appropriate natural killer cell inhibitory receptors in women with spontaneous abortion.

Previous studies have revealed that women with unexplained recurrent spontaneous abortions have a limited repertoire of inhibitory KI receptors (inhKIRs) and that the inhKIRs they possess do not have specificity for the human leukocyte antigen (HLA)-Cw molecules that would be expressed on trophoblast. We sought to confirm these findings by direct definition of maternal inhKIR and trophoblastic HLA-Cw allotypes on the placental material of spontaneously missed pregnancies. The study included 30 women undergoing vacuum uterine curettage for first-trimester missed pregnancy (group A; n = 15) or for elective termination of normal pregnancy (group C, n = 15). DNA extracted from isolated decidual and trophoblastic cells was used for molecular detection of maternal inhKIRs (2DL1, 2DL2, 2DL3) and fetal HLA-Cw alleles, respectively. The results revealed that in the group of women who experienced abortion, 60% did not have the full repertoire of three inhKIRs (group A vs group C; p = 0.006); that in five of 15 patients (none in the controls), no epitope matching existed between maternal inhKIRs and trophoblastic HLA-Cw alleles (group A vs group C; p = 0.01); and that more cases were found with limited epitope matching (less than three inhKIRs with specificity for fetal HLA-Cw alleles). The results provide additional evidence that in some cases of spontaneous abortions, the women lack the appropriate inhKIRs to interact with the HLA-Cw molecules on trophoblasts and to deliver signals to inhibit natural killer cell activation and protect the embryo.

Role of a KIR/HLA-C allorecognition system in pregnancy.

Decidual natural killer (NK) cells are thought to play a significant role in the allorecognition mechanisms during pregnancy. Through their activating and inhibitory receptors they may recognize selectively class I HLA alleles expressed on invading trophoblast and provide self-signals to control NK responses, thus regulating the maternal immune response at the fetomatenal interface. Killer immunoglobulin-like receptors (KIR) constitute one of the families of class I MHC receptors which are expressed on NK cells. Their repertoire includes both activating and inhibitory receptors, most of which recognize specific epitopes on HLA-C molecules and can either activate NK cell responses or abort activating signals and inhibit NK cell functions. Since KIRs are expressed on decidual NK cells and the HLA-C molecules that they recognize are also expressed on invading trophoblast, KIR receptors may play a regulatory role in pregnancy by interacting with their trophoblastic HLA-C counterparts and providing trophoblast damage evading signals (KIR/HLA-C allorecognition system). Our hypothesis that the KIR/HLA-C system might be ineffective in some unsuccessful pregnancies, has been investigated in women with unexplained spontaneous abortions. Our results suggest that a limited maternal repertoire of inhibiting KIRs (inhKIRs) and/or lack of maternal inhKIR-fetal HLA-C epitope matching may predispose to miscarriage.

Donor work-up and transport of bone marrow--recommendations and requirements for a standardized practice throughout the world from the Donor Registries and Quality Assurance Working Groups of the World Marrow Donor Association (WMDA).

In October 1995 the World Marrow Donor Association (WMDA) was restructured in order to facilitate its primary function of establishing guidelines in relation to international bone marrow and blood stem cell transplants -- transplants in which the donor is in one country and the patient is in another country. Five new working groups were established -- Donor Registries, Ethics, Quality Assurance, Finances, and Stem Cells. This paper, prepared by members of the Donor Registries Working Group, in consultation with the Quality Assurance Working Group, provides recommendations for the 'donor work-up'. This term covers events that start when the definitive donor has been identified, includes the harvesting (collection) and transportation of the stem cell product and ends when the product reaches the transplant centre. The paper includes examples of the documentation intended to ensure compliance with the recommendations at all key points in the sequence.

HLA-associated non-responsiveness to hepatitis B vaccine.

HLA-A,B,DR antigens of two groups, one of normal individuals (N- = 31) and another of CRF (Chronic Renal Failure) patients (K- = 37), who did not develop anti-HBs protective antibodies after Hepatitis B (HB) vaccination, were compared, respectively, to the HLA antigens of two corresponding control groups (N+ = 52, K+ = 49), who responded to the vaccine. A statistically significant difference (Pc less than 0.02) in the frequency of HLA-DR3 was observed between responders and non-responders. An increased frequency of HLA-A1 and HLA-B8 in N- as well as of HLA-A1 and HLA-B35 in K- was also noticed, but this was not of statistical significance. As these antigens have been associated to both HBs antigenemia as well as chronic active hepatitis, we suggest that these genes or other genes in linkage to those may suppress the response to HBV vaccination while, in parallel, they may predispose to an autoimmune course of Hepatitis.

HLA-A,-B, and -DR antigens in relation to gold and D-penicillamine toxicity in Greek patients with RA.

Ninety-five rheumatoid arthritis patients treated with aurothiomalate and/or D-penicillamine have been studied for possible associations between HLA-A, -B, -DR antigens and various toxic reactions to the above drugs. HLA-DR3 and -DRw6 had a higher frequency in patients with toxic reactions (all types) than in patients without toxic reactions (28.5 per cent vs 13.0 per cent and 26.5 per cent vs 4.3 per cent, chi 2 = 2.6 and 7.2, respectively). HLA-B8 was found at a higher frequency in patients with proteinuria and other types of renal involvement (20.0 per cent vs 7.4 per cent in controls), whereas skin manifestations were mainly associated with the presence of HLA-DRw6. The lowest frequency of side-effects was seen in patients with HLA-DR1 and DR2 (10.2 per cent vs 28.3 per cent and 28.5 per cent vs 54.3 per cent, chi 2 = 3.9 and 5.5, respectively). In addition, seropositive patients possessing HLA-DR1, showed toxic reactions less frequently.

Human lymphocyte antigens A, B, and C in Greek patients with psoriasis: relation to age and clinical expression of the disease.

The frequencies of human lymphocyte antigens (HLAs) A, B, and Cw6 were studied in a group of 212 Greek patients with psoriasis and 202 control subjects. An increased frequency of B13, B16, and Cw6 antigens and a low frequency of B14 were noted in the group of all patients. However, there were striking differences in HLA phenotypes according to the age at onset of the disease. Early onset (less than 25 years of age) was associated with a high frequency of A1, B17, B37, and Cw6 antigens, whereas patients with late onset (greater than 25 years of age) had a significantly lower incidence of A1, B17, and Cw6, which did not differ from that of the control subjects. Patients with onset of the disease greater than 60 years of age had, in addition, an increased frequency of B16. Psoriatic erythroderma was characterized by an increase of Aw19 and a higher frequency of B13 than in the total group of patients with psoriasis. In patients with a familial incidence of the disease, there was no significant association with any particular HLA.