Biomedical subjects
Publications and source records attributed to P Platz.
Thirteen patients with severe aplastic anemia (AA) were HLA-DP typed using primed lymphocyte typing (PLT). The frequency of HLA-DPw3 was significantly increased to 69% in AA as compared to 22% in 160 controls (p less than 0.001; corrected p less than 0.01, RR = 8.0).
Thirteen recipients of HLA-haploidentical, DR compatible bone marrow (BM) and the corresponding BM donors were HLA-DP typed using primed lymphocyte typing (PLT). Severe acute GVHD (greater than or equal to grade 2) developed within 3 months after BM-transplantation in all of eight recipients of DP incompatible BM, but in none of five recipients of DP-compatible BM. This difference was highly significant (p less than 0.001, Fisher's exact test). Moreover, severe acute GVHD was significantly increased in recipients of haploidentical, DR compatible, but DP incompatible BM as compared to severe acute GVHD in 88 recipients of HLA-identical BM (p less than 0.0001). In contrast, there was no difference in acute GVHD between recipients of haploidentical, DR and DP compatible BM and recipients of HLA-identical BM. The data presented here provide strong evidence for the first time that HLA-DP antigens play a role as transplantation antigens.
Stored peripheral blood or bone marrow mononuclear cells from 22 pediatric patients with verified acute lymphoblastic leukemia (ALL) previously classified as non-T, non-B ALL were re-investigated by flow cytometric analysis by means of a panel of B cell-specific and -associated monoclonal antibodies (moabs) using a new analytical method described by Platz et al, the so-called Delta Channel Value method. All 22 patients were immunologically re-characterized as pre-B ALL. The reproducibility between the first (acute) and subsequent re-analysis was almost complete. 20 of the tumor cell populations could be assigned to the B cell differentiation scheme recently proposed by Nadler et al. This scheme operates with four stages of pre-B cell differentiation and each stage is defined by the expression of one to four of the following markers: HLA-DR, CD19, CD10 and CD20. Two additional markers, CD24 and CD22, were investigated in our study and allowed further subdivision of the four subgroups proposed by Nadler et al. The composition of a panel of moabs for routine classification of pre-B ALL is proposed.
The presence of activated T cells as judged from the reaction with monoclonal antibodies (MoAb) against (a) a late stage T cell activation antigen (VLA-1), (b) the interleukin 2 (IL2) receptor (CD25), and (c) four different HLA class II molecules (HLA-DR, DRw52, DQ, and DP) was studied in 15 patients with active juvenile chronic arthritis (JCA), 10 patients with JCA in remission, and 11 age matched, healthy controls. In addition, the distribution of T 'helper/inducer' (CD4+), T 'suppressor/inducer' (CD4+, Leu8+), T 'suppressor/cytotoxic' (CD8+), and 'natural killer' (NK) cells (CD16+) was studied. Twenty patients and six controls were investigated for the capability to stimulate alloreactivated primed lymphocytes. The prevalence of VLA-1 positive, large cells was significantly increased to 5% (median value) in active JCA as compared with JCA in remission (2%, p less than 0.05) and controls (1%, p less than 0.05), whereas no significant difference between JCA in remission and controls was observed. Except for two patients with active JCA, less than 1% IL2 receptor bearing cells were found in patients with JCA and controls. No significant difference in the prevalence and expression of the various HLA class II antigens was observed between the groups. Similarly, no significant differences in stimulatory capability in secondary mixed lymphocyte culture (MLC) were seen. The distribution of T helper/inducer (CD4+), T suppressor/cytotoxic (CD8+), and NK cells was similar in active JCA, JCA in remission, and controls. The prevalence of T suppressor/inducer (CD4+,Leu8+) cells was higher in remission JCA (17%) than in active JCA (11%) and controls (10%). This increase, however, did not reach statistical significance. In conclusion, late stage but not early stage T cell activation antigens were increased in patients with active JCA as compared with patients with JCA in remission and control, whereas some patients in remission had an increased prevalence of T suppressor/inducer cells.
We studied the effects of exogenous T cell growth factor (TCGF) (= interleukin-2) and indomethacine on the lymphocyte transformation response in vitro to allogeneic cells, mitogens, and antigens in AIDS patients, those with AIDS-related complex (ARC), and in healthy controls. While low amounts of TCGF reduced the response of peripheral blood mononuclear cells (PBMC) to allogeneic cells in both healthy controls and AIDS patients, large amounts of TCGF augmented the response in both groups, although the response of the patients' cells were still subnormal. By depleting the PBMC for either CD4-positive or CD8-positive cells, the effect of TCGF on suboptimally mitogen-stimulated PBMC from controls was shown to be due to an increased response in both the CD4-positive and the CD8-positive cells. In contrast, with patient cells, TCGF only increased the response of the CD4-positive cells, while that of the CD8-positive cells was largely unchanged. Thus, the lack of normalization of the mitogen response of patient cells upon addition of TCGF may be largely due to unresponsiveness of CD8-positive cells to TCGF. This observation further supports the idea that CD8-positive cells are abnormal. To investigate the role of the inhibitor of TCGF production, PGE2, in AIDS, indomethacine was added to cultures of mitogen-stimulated PBMC from controls and patients. No differences were found between the three groups: the responses to PHA were slightly increased and those to Con A were unchanged.
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.
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The lymphocyte transformation responses to mitogens (phytohaemagglutinin (PHA), concanavalin A (Con A), and pokeweed mitogen (PWM)), allogeneic cells, and the antigen-purified protein derivative (PPD) were studied in six acquired immunodeficiency syndrome (AIDS) patients and in six healthy controls, each of whom was HLA-DR- and mixed lymphocyte culture (MLC)-identical with one of the AIDS patients. No evidence of suppression was observed when irradiated or non-irradiated AIDS peripheral blood mononuclear cells (PBMC) were added to cultures of HLA-DR-identical PMBC from healthy controls stimulated with the strong mitogens PHA and Con A or with allogeneic cells, but suppression may be involved in the decreased responses in cultures stimulated with PWM or PPD. Addition of supernatants from macrocultures of AIDS cells did not suppress responses of control PBMC. Thus, suppression by any lymphocyte subset or soluble factor alone cannot explain the generally severely depressed transformation responses in AIDS. Addition of heavily irradiated HLA-DR-identical PBMC from healthy controls or supernatants from these cultures led to increased responses in cultures of mitogen-stimulated AIDS PBMC and in some cultures of antigen or allogeneic cell-stimulated AIDS PBMC, which were of the same magnitude as seen after the addition of commercially obtained T-cell growth factor (TCGF). This indicates that AIDS cells are deficient in producing TCGF. Heavily irradiated AIDS PBMC were capable of restoring the transformation responses to mitogens and antigens of purified HLA-DR-identical normal T cells, indicating that AIDS cells have a normal antigen-presenting capacity and interleukin (IL-1) production. However, AIDS PBMC had a very poor capacity to stimulate normal PBMC in MLC. Together, our experiments suggest that the immune deficiency in AIDS cells may be partially due to a decreased capability of T lymphocytes to produce TCGF and that a decreased number and/or function of dendritic cells may also be involved.
Lymphocytes from highly selected donors were primed for 10 days and subsequently bulk-expanded in IL 2 (TCGF) containing cultures. Two well-discriminatory PLT (CDP = Copenhagen DP) reagents against each of the DPw1-w6 specificities and one against each of the two "new" specificities, CDP4s and CDPHEI, were selected for further studies. Three combinations made in two recombinant families and four of ten HLA-A, B, and DR compatible combinations discriminated well in contrast to seven of 46 DR compatible, but HLA-A or B incompatible combinations. All reagents gave highly reproducible results, and high correlations (r-values between 0.73-1.00) for DP assignments were obtained with CDP and GNN reagents. No triplets were found for the DPw1-w6 and CDP HEI specificities. The "new" specificity CDP HEI defined in an HLA-DR/GLO recombinant family gave a coefficient of correlation with GNN 8 of 0.91. Another "new" specificity, CDP4s constitutes a subgroup ("split") of DPw4. The gene frequencies of DPw1-w6 estimated in 102 unrelated randomly selected Danes agreed with those reported for other Caucasoid populations. The gene frequencies CDP HEI and CDP4s were 0.03 and 0.08, respectively. The associations between DR3-DPw1, DR2-DPw4, and DRw6-DPw2 were confirmed. It is concluded that DP-typing with bulk-expanded reagents is a reliable and so far the only technique which can reveal the polymorphism of the DP gene products.
A total of 317 unrelated Danish patients with insulin-dependent diabetes mellitus (IDDM) have been HLA-DR typed and the antigen and phenotype frequencies compared with those in 1177 unrelated Danish controls. The strong positive associations with DR3 and 4 and the strong negative one with DR2 were confirmed, and the remaining antigens showed a hierarchy from weakly positive to strongly negative associations: DRw9, w8, 1, 5, w6, 7. The study population included various special groups of patients selected in order to study heterogeneity: very early (less than 5 years) and very late (greater than 40 years) onset IDDM, pregnancy-induced IDDM, IDDM nephropathy, and long-term (greater than 40 years) survivors without complications. When comparing these groups, the following minor differences were seen: the DR3,4 phenotype is significantly (p = .02) more frequent in IDDM with onset before age 20 (35%) than in other cases (24%), and in familial IDDM (48%) than in other cases (28%); the frequency of the DR4 antigen was significantly (p = .008) more frequent in long-term survivors (86%) than in other patients (69%), while it was significantly (p = .02) less frequent in IDDM nephropathy (63%) than in long-term survivors. However, apart from the age-at-onset heterogeneity, which was suspected a priori, these differences may be due to chance, and the main conclusion of this study is that the HLA-DR associations in IDDM are indeed extraordinarily homogeneous irrespective of the clinical characteristics at onset and course of the disease.
Thirty-six unrelated Danish patients with pauciarticular Juvenile Chronic Arthritis (PJCA) and 120 controls were typed for HLA-DPw1-w6 and the local specificity CDPHEI with bulk-expanded Primed Lymphocyte Typing (PLT) cells. The frequency of HLA-DPw2 was 52.8% in PJCA patients and 16.7% in controls (relative risk, RR = 4.5; P less than 0.001). The antigens HLA-Dw5 and/or Dw8 were present in 50% of the patients and in 21.3% of the controls (RR = 4.2; p less than 10(-3)). DPw2 was not associated (in linkage disequilibrium) with Dw5/w8 in patients or in controls, and the DP and D associations with PJCA were independent of each other. However, the combined presence of DPw2 and Dw5 and/or Dw8 gave a significantly higher risk of PJCA than each antigen alone indicating interaction of DP and DR gene products. PJCA is the first disease definitely found to be associated with a DP antigen.
A pregnancy-induced alloantibody has allowed definition of a class II HLA antigen, AE, which has a frequency of about 10% in Danes, is completely included in DR4, and highly significantly (p = 10(-9)) associated with the cellularly defined Dw14 determinant which is completely included in AE. AE is absent on Dw4 and Dw13 cells, but was also found on one Dw15 HTC and in two of four Dw10-positive cells. It is in positive linkage disequilibrium with B40 but not with B15 or B44. It is hypothesized that the AE specificity is due to the co-occurrence of an arginine in position 71 and an alanine in position 86 of the first domain of the DR beta 1 chain. However, it cannot be excluded that this antigen belongs to another class II series.
We studied the influence of HLA class I and class II antigens on the suppression of the MLR induced by primed lymphocytes (PLs) alloactivated in vitro. The suppression of 14 different PLs of 83 MLRs was analyzed. The PLs were primed against (i) HLA-DP (SB) (ii) HLA-DR/DQ or (iii) both HLA-DP and DR/DQ. The suppression was analyzed with special reference to the sharing of HLA-antigens between (i) the stimulator in the MLR and (ii) the stimulator generating the PL. HLA-DP and HLA-DR/DQ antigens were equally capable of generating suppressor cells. When these cells were added to MLRs, the specific stimulators induced the strongest suppression (74%), while allogeic cells sharing class II antigens induced a slightly weaker suppression (66%). The suppression related to HLA-DP (60%) was almost identical to that related to HLA-DR/DQ (59%). The HLA-A, B, C related suppression was of the same magnitude (58%). The unspecific suppression (40%), i.e. no relation to known HLA-antigens, was significantly lower than the class II related suppression, but not significantly lower than the class I related suppression. The suppression of the MLR did not seem to be caused by cytotoxic cells, consumption of lymphokines, nor changes in the kinetics of the MLR. Thus, HLA-DP antigens can-like DR/DQ antigens - induce PLs with the ability to suppress the MLR in an HLA-class II (DP or DR/DQ) related, and possibly a class I related, as well as an unspecific fashion.
HLA typing of an HLA-B/GLO recombinant family using bulk-expanded DP(SB) alloreactive T-cells (GNN1 to 6) as well as conventional HLA-ABC, D, DR, and DQ typing showed that a paternal recombination had taken place between HLA-DR and DQ on the one hand and HLA-DP(SB) on the other. The recombinant child was DPw4,6-heterozygous and differed in terms of class II determinants only for DPw6 from two otherwise HLA identical siblings, who were probably DPw4/4-homozygous. These siblings did not stimulate the recombinant in MLC whereas they responded to his cells indicating that DPw6 can stimulate in primary MLC. Moreover, it was possible to generate and bulk-expand DPw6-reactive lymphocytes (PLs) between MT and MA as responders and BN as stimulator. The correlation coefficient (r) between the reaction of these PLs and the GNN6 (anti-DPw6) reagents was 1.0 when tested against a panel of 71 individuals. This is the first report demonstrating that the DPw6 gene, like the DPw1-w5 genes, is located between DR/DQ and GLO. The frequency of the DPw6 antigen in 41 unrelated, randomly selected Danes was 7%. HLA-DP typing of the BN family revealed that the DPw6 positive but not DPw6 negative family members gave intermediate responses with one (GNN2B) but not with another (GNN2A) anti-DPw2-reagent. Studies of 63 healthy individuals (unrelated to the BN family) revealed seven similar discrepancies between GNN2A and GNN2B. Strikingly, all four DPw6 positive stimulators gave rise to such discrepancies indicating that the GNN2B reagent is cross-reactive and recognize a common part of the DPw2 and DPw6 molecules. No cases of GNN2A+/GNN2B- stimulators were found.
Chronic graft-versus-host disease (GvHD) in bone marrow allograft recipients is frequently preceded by a cytomegalovirus (CMV) infection. To elucidate whether an immune reaction of transplanted donor cells against CMV was involved in the pathogenesis of chronic GvHD, the effect of donor pretransplant CMV immune status on chronic GvHD incidence was analyzed. In 43 bone marrow recipients at risk, the 2-yr cumulative chronic GvHD probability was 55% when the donor was immune, in contrast to 16.5% when the donor was non-immune (p less than 0.002). No correlation between recipient pretransplant CMV immunity and chronic GvHD was observed. Donor CMV immunity did not correlate with acute GvHD or posttranplant CMV infection and seemed to predispose for chronic GvHD regardless of donor and recipient age. However, the proportion of CMV immune donors increased with increasing donor and recipient age. This may account for the higher incidence of chronic GvHD in older patients. The present study suggests that chronic GvHD may be mediated by a reaction of immune donor cells against CMV infected recipient cells.
A new homozygous typing cell (HTC), SK is described. Mixed leukocyte culture (MLC) showed that SK is homozygous for HLA-D"H" (DB6) defined by the HTC, Herluf, and that the HLA-D typing results obtained by Herluf and SK are highly significantly correlated (Kendall's R = 0.46, p = 2.5 X 10(-5)). Both Herluf and SK are also homozygous for a new class II determinant, DN-1, defined by the monoclonal anti-B-lymphocyte antibody, 9w925, developed by Aizawa. The corresponding DN-1 antigen was present in 2.2% of 136 random, unrelated Danes and in all of six unrelated HLA-D"H" positive but in none of 20 HLA-D"H" negative individuals. Thus, there is an absolute and highly significant (p = 4 X 10(-6)) association between the cellularly defined HLA-D"H" determinant and the serologically defined DN-1 antigen, which strongly suggests that HLA-D"H" can now be detected serologically. DN-1 may be identical to DRw12 which is, however, poorly defined. The HTC-donor SK was immunized by pregnancy, and her serum contains anti-HLA-B7, which can easily be absorbed, and anti-B-lymphocyte antibodies which reacted with cells from 87.7% of 536 unrelated Danes. The reaction pattern of this serum is negatively associated with DR3, w6, and w8. This serum may define a new broad, cross-reacting antigen belonging to the same group as DRw52 and DRw53 or DQw1-w3, but it is clearly different from each of these antigens.
We studied a classical case of late-onset rubella syndrome characterized by multi-organ disease and persistence of live rubella virus in spite of high titres of specific antirubella antibodies and presence of large amounts of circulating immune complexes. When first studied at the age of 5 months there was a low proportion of T8+ lymphocytes. Functional studies revealed decreased activity of K and NK cells as well as alloreactive direct cytotoxic cells (CTL). Removal of cell-bound immunoglobulin and immune complexes tended to improve K and NK cell function in vitro. Plasma exchange transfusions carried out at 9 months of age resulted in clinical improvement. Normalization of cytotoxic effector cell functions and cessation of viremia accompanied recovery from active disease. The results indicate that defective cytotoxic effector cell function is the primary cause for the defective virus elimination in this syndrome.
We report a combined segregation and linkage analysis of a Danish sample of 216 insulin-dependent diabetes mellitus (IDDM) nuclear families: of these 216, twenty multiplex families were haplotyped regarding HLA-DR and -B markers. The analysis was conducted using the computer program COMBIN, which includes a modifier to absorb family resemblance that is additional to the effect of the major locus that is assumed linked to a marker locus, eg, within the HLA region. The initial analysis could clearly reject a dominant major locus but could not discriminate between other models with or without modifier. However, after adding supplementary information on population associations between HLA and IDDM together with the identity-by-descent (IBD) distribution to the analysis, a final model was identified. This invokes an additive major locus, linked to HLA with recombination not significantly different from 0, a disease gene frequency of 0.217, plus a dominant modifier. From this model it can be predicted that about 0.15% of the general population is at 100% risk of IDDM, about 5% is at intermediate risk (approximately 10%), while the remaining population has a risk of 0. The model predicts recurrence risks compatible with empirically estimated values. Particularly strong, positive haplotype associations were found for the DR3,B8, DR3,B18, and DR4,B15 haplotypes, but detailed analyses showed that neither these particular haplotypes nor the DR3 and DR4 haplotypes in general could entirely explain the HLA-associated susceptibility. The DR2 haplotypes showed a strong negative association. The results are discussed in the light of available data on the epidemiology of IDDM in order to provide a framework for further epidemiological studies.