Search PubMed⌕ Search

Biomedical subjects

A Svejgaard

Publications and source records attributed to A Svejgaard.

At least 199 records · Page 11Linked to original sources
PubMed1986

Recipient lymphocyte sensitivity to methylprednisolone affects cadaver kidney graft survival.

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.

Cadaver↗
PubMed1986

A standard microcytotoxicity technique for quantitative analysis of lymphocyte subsets. A comparison with indirect immunofluorescence, evaluated by microscopy or flow cytometry.

A standard complement-dependent microcytotoxicity (CDC) technique was used for quantitative analysis of T-lymphocyte subsets in human peripheral blood and the results compared to those obtained by indirect immunofluorescence microscopy and flow cytometry. The monoclonal antibodies OKT3, OKT4 and OKT8 were used in the CDC method for detection of total-T cells, T-helper and T-suppressor cells respectively. The CDC technique provided reproducible results (CV, 3-7%) correlating well with both immunofluorescence techniques. This observation was valid both for healthy persons (n = 21) and for patients (n = 10) with immunological disorders. The correct antibody dilution, correction for background and the use of eosin staining are considered critical for the usefulness of this technique. The method has several advantages: it is widely used for histocompatibility testing, only simple equipment is necessary, and the amount of monoclonal antibody required per test is small.

Antibodies, Monoclonal↗
PubMed1986

Influence of previous gold treatment and other patient variables on outcome of treatment with disease modifying anti-rheumatic drugs (DMARD) in patients with rheumatoid arthritis.

Based on a 2-year controlled double-blind trial of levamisole, penicillamine, and azathioprine (L, P, and A), a computer aided search for predictive factors of outcome was instituted. Already at month 4 several indicators of synovitis activity were able to discriminate between patients staying in the trial for 24 months and patients whose treatment was discontinued before that time. Patients who had previously received gold therapy responded less favourably to L, P, and A than those who had not received gold. This reduction of response was more pronounced in gold resistant patients than in patients whose gold treatment had been discontinued for other reasons. The only phase protein (of several) with a predictive value was haptoglobin. If, after 4 months of treatment, haptoglobin did not normalize, this finding indicated a lack of response to treatment or a deterioration of synovitis activity during the following 4 months. The response to treatment was not influenced by HLA-types, sex, age, or clinical synovitis, disease duration, functional or anatomical aberrations at the start of treatment. The shape of the response curve as reflected by means of monthly measurements of serum-albumin and ESR was not related to disease duration, HLA-types, or previous gold treatment.

Arthritis, Rheumatoid↗
PubMed1986

Post-transfusion purpura (PTP) due to anti-Zwb (-PlA2): the significance of IgG3 antibodies in PTP.

The first two patients with post-transfusion purpura (PTP) due to platelet antibodies against the Zwb antigen are reported. The anti-Zwb specificity could be demonstrated only with an enzyme-linked immunosorbent assay (ELISA) but not with the immunofluorescence or the complement fixation test due to coexistent potent multispecific HLA antibodies. One of the patients had never received blood transfusion until 24 d before the development of thrombocytopenic purpura. In both patients, anti-Zwb of IgG1 and IgG3 subclasses defined by monoclonal antibodies were present during the thrombocytopenic period but the antibodies of IgG3 subclass disappeared concomitantly with clinical improvement. The association between the IgG3 subclass of anti-Zw antibodies and the destruction of autologous platelets in Zw-immunized individuals was investigated further. All of four PTP patients had anti-Zw antibodies of the IgG1 and IgG3 subclasses during the thrombocytopenic period while all of 20 mothers of children affected with alloimmune neonatal thrombocytopenia (AINT) had anti-Zwa of only the IgG1 and not IgG3 subclass at the time of delivery of thrombocytopenic children (P less than 10(-4). Thus, the destruction of autologous platelets in PTP is associated with the presence of anti-Zw of the IgG3 subclass which may be of importance in the pathogenesis of PTP.

Aged↗
PubMed1986

Immunological studies in the acquired immunodeficiency syndrome. II. Active suppression or intrinsic defect--investigated by mixing AIDS cells with HLA-DR identical normal cells.

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.

Acquired Immunodeficiency Syndrome↗
PubMed1986

The HLA-DP polymorphism in Denmark investigated by local and international PLT reagents. Definition of two "new" DP antigens.

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.

Cells, Cultured↗
PubMed1986

HLA associations in insulin-dependent diabetes: search for heterogeneity in different groups of patients from a homogeneous population.

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.

Age Factors↗
PubMed1986

Increased frequency of HLA-DPw2 in pauciarticular onset juvenile chronic arthritis.

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.

Arthritis, Juvenile↗
PubMed1986

An alloantibody against a class II antigen subtypic to HLA-DR4 and strongly associated with the cellularly defined Dw14 determinant.

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.

Antibody Specificity↗
PubMed1986

HLA-DP related suppression of mixed lymphocyte reaction with alloactivated lymphocytes.

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.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1986

An HLA-DR/DP recombinant family involving DPw6. Evidence for cross-reactivity between DPw6 and GNN2B.

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.

Alleles↗
PubMed1986

A new homozygous typing cell with HLA-D"H" (DB6) specificity. Evidence that the DN-1 monoclonal antibody 9w925 is specific for the HLA-D"H" determinant.

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.

Adult↗
PubMed1985

The genetic susceptibility to insulin-dependent diabetes mellitus: combined segregation and linkage analysis.

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.

Diabetes Mellitus, Type 1↗
PubMed1985

Immunological studies in acquired immunodeficiency syndrome. Functional studies of lymphocyte subpopulations.

The lymphocyte transformation response in vitro to mitogens (phytohaemagglutinin, concanavalin A, and pokeweed mitogen) and antigens (purified protein derivative and tetanus) was studied in three patients with acquired immunodeficiency syndrome (AIDS), three patients with pre-AIDS, and six healthy controls before and after depletion of T4- or T8-positive cells. In controls, T8-depleted lymphocytes responded as well as peripheral blood mononuclear cells (PBMC) when monocytes were added, whereas T4-depleted cells gave about 50% of this response to mitogens and no response at all to antigens. No evidence of suppression was seen when various mixtures of T4- and T8-depleted cells were made. In particular, there was a virtually linear relationship between the percentage of T8-depleted cells and the response to antigens. The PBMC of all AIDS and pre-AIDS patients had very low or absent responses to mitogens and antigens, and except in one case, this response did not increase after depletion of T8-positive cells (and addition of monocytes), indicating that these patient cells also lack suppressor activity in this assay. However, a significantly increased response to mitogens was seen when the T8-depleted suspensions were adjusted to contain 20,000 T4-positive cells per well, but the response was still significantly lower than that of similar suspensions from controls. Thus, not only are the poor responses of PBMC from AIDS and pre-AIDS patients due to a low concentration of T4-positive cells, but the responsiveness of these cells also seems deficient. Furthermore, T8-positive patient cells also have an impaired responsiveness. Our experiments do not exclude the possibility that the low response is due to a T8-negative suppressor cell, but it seems more likely that both the T4- and the T8-positive cells are deficient and/or that there is a deficiency in accessory cells. These possibilities are currently under study.

Acquired Immunodeficiency Syndrome↗