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Biomedical subjects

G Biberfeld

Publications and source records attributed to G Biberfeld.

At least 181 records · Page 10Linked to original sources

T-cell helper activity and B-cell function of synovial and blood lymphocytes from patients with rheumatoid arthritis or other forms of chronic arthritis.

The helper effect of T cells on B-cell immunoglobulin (Ig) responses induced by pokeweed mitogen (PWM) or purified protein derivative of tuberculin (PPD) was studied in lymphocytes from synovial fluid (SF) and blood of nine patients with rheumatoid arthritis (RA) and eight patients with other forms of chronic arthritis. In PWM cultures the helper effect of SF T cells on Ig responses (IgG, IgM, IgA) of autologous and allogeneic blood B cells was lower than that of blood T cells (P less than 0.01). This decrease was more pronounced in patients with RA than in patients with non-RA. In PPD cultures no significant difference was found between the helper effect of SF T cells and blood T cells on the Ig responses of allogeneic blood B cells or on the IgG response of autologous blood B cells, whereas the helper effect of SF T cells on the IgM and IgA responses of autologous blood B cells was decreased. The Ig responses to PWM or PPD in cocultures of autologous blood B and T cells were not significantly different between patients and healthy controls. The PWM- and PPD-induced Ig responses of SF B cells were lower than those of blood B cells when cocultured with autologous blood T cells. SF B cells produced IgG but usually little IgM and IgA. Thus there was a dysfunction of SF B cells and of SF T cells in a PWM-driven system, but a fairly good helper function of SF T cells in a PPD-driven system.

Adult↗

Immunoregulatory function of T8 and T4 cells from synovial fluid and blood of patients with rheumatoid arthritis or other forms of chronic arthritis.

The suppressor effect of synovial fluid (SF) T8 cells and blood T8 cells on the pokeweed mitogen (PWM)-induced T4 cell-dependent immunoglobulin production of autologous blood B cells was studied in nine patients with chronic rheumatic diseases (six patients with rheumatoid arthritis (RA), one patient with juvenile RA, and two patients with other forms of chronic arthritis). The suppressor effect of SF T8 cells was of the same magnitude as that of equal numbers of blood T8 cells from patients and healthy controls. However, the relative number of T8 cells was higher among SF T cells than among blood T cells in several cases. Good synovial T8 cell suppression was also demonstrated in coculture experiments where SF T4 cells and B cells were used. In PPD (purified protein derivative of tuberculin)-stimulated cultures the suppressor effect of SF T8 cells as well as of blood T8 cells from patients and controls was lower than it was in PWM-stimulated cultures. In most patients SF T4 cells showed a much better PWM-induced helper function than did non-fractionated SF T cells. Thus the poor PWM induced helper effect of non fractionated synovial T cells was in some cases mainly due to the suppressor effect of T8 cells, whereas in some cases there was also a deficient helper function of synovial T4 cells.

Adult↗

Transmission of HIV infection to heterosexual partners but not to household contacts of seropositive haemophiliacs.

The prevalence of HIV antibodies in 44 heterosexual female partners and 56 nonsexual family household contacts of 61 HIV seropositive haemophiliacs (41 adults and 20 children or adolescents) was determined to evaluate the risk of transmission of HIV infection. HIV antibodies were determined by enzyme-linked immunosorbent assay and positive reactions were confirmed by Western blotting. HIV antibodies were demonstrated in 4/40 (10%) regular heterosexual partners of 40 seropositive patients with haemophilia A. Four temporary heterosexual partners of one additional seropositive haemophiliac were seronegative. 56 nonsexual household contacts including 30 parents, 13 siblings and 13 children of 29 seropositive haemophiliacs were all negative for HIV antibodies. Thus transmission of HIV occurred from seropositive haemophiliacs to their heterosexual partners but not to nonsexual household contacts.

Acquired Immunodeficiency Syndrome↗

T8 cell suppression of antigen- and mitogen-induced T4 cell dependent immunoglobulin production.

The suppressor effect of T8 cells on antigen-induced, as compared to pokeweed mitogen-induced, T4 cell dependent immunoglobulin (Ig) production by B cells of healthy subjects was studied. The antigens used were purified protein derivative of tuberculin (PPD) and tetanus toxoid (TT). The suppressor effect of T8 cells on IgG, IgM and IgA responses in co-cultures of T4 cells and B cells was significantly stronger in the pokeweed mitogen driven system than in PPD- and TT-driven cultures under the same experimental conditions.

Adult↗

HTLV-III expression in infected lymph nodes and relevance to pathogenesis of lymphadenopathy.

In situ hybridization with a 35S-labeled probe of cryosections from 14 lymph nodes of HTLV-III/LAV-seropositive individuals with lymphadenopathy showed the presence of rare cells containing HTLV-III RNA at levels consistent with virus replication. Positive cells were observed at a frequency of only 1-10 per section. In all lymph nodes studied, including those showing follicular hyperplasia or involution, most of the cells expressing viral RNA were present in the follicular areas. Only a minority of such cells were found outside the follicles. The nature of the follicular, virus-replicating cells was not evident from the processed cryosections. After prolonged autoradiography, another pattern of hybridization was observed, suggesting low levels of viral RNA diffusely distributed throughout most, but not all, follicles. This may represent extracellular virus and/or virus-antibody complexes, but was not consistent with intracellular viral RNA or phagocytosed virus particles. Comparison of hybridization levels in relation to histology suggested a decrease in both the number of HTLV-III replicating cells as well as in the diffusely distributed viral RNA with progression of follicular involution. Our observations indicate that in HTLV-III-infected subjects, lymph node follicles are an important site of virus replication and trapping, suggesting a decisive role of the virus in the characteristic reactive and cytopathogenic changes of HTLV-III-associated lymphadenopathy.

AIDS-Related Complex↗

Autoantibodies to the basal cells of squamous epithelium react with thymic epithelial cells.

Sera from carriers of hepatitis B surface antigen (17 out of 21), which reacted in immunofluorescence with the basal cell layer (BCL) of squamous epithelium, were also shown to react with a thymic stellate epithelial cell (SEC) characterized by long, dendritic-like cytoplasmic processes. Absorption of the autoantibodies against BCL of squamous epithelium (BCL-Ab) with a thymic homogenate abolished the reactivity with BCL and SEC, demonstrating that the same antigenic determinant was recognized in both cells. In the human thymus, SEC were present both in the cortex and in the medulla. In the outer cortex SEC delineated the septal spaces. SEC were also stained by anti-HLA-DR (Ia) but not by antiactin monoclonal antibodies. The morphology and distribution of SEC were similar to those of the previously described thymic epithelial cells containing alpha-1 thymosin (K. Hirokawa, J. E. McClure, and A. L. Goldstein, Thymus 4, 19, 1982). BCL-Ab were also found to react with five human epithelial thymomas. BCL-Ab seemed to be useful for further characterization of the thymic epithelial cells and for the immunodiagnosis of thymoma.

Actins↗

Antibodies to human T lymphotropic virus type III demonstrated by a dot immunobinding assay.

A dot immunobinding (DIB) technique was applied to the demonstration of antibodies to human T-lymphotropic virus type III (HTLV-III). By this technique IgG antibodies to HTLV-III were demonstrated in six of six Swedish patients with acquired immune deficiency syndrome and in 37 of 39 (95%) Swedish homosexual men with persistent generalized lymphadenopathy but in none of 50 Swedish healthy blood donors. Findings obtained by this method showed complete concordance with those obtained by an enzyme-linked immunosorbent assay. All sera positive by DIB were also positive by Western blotting. The DIB assay is simple and well suited for screening of sera for HTLV-III antibodies.

Acquired Immunodeficiency Syndrome↗

Immunohistopathology of lymph nodes in HTLV-III infected homosexuals with persistent adenopathy or AIDS.

Lymph node biopsies from 43 male homosexuals with persistent generalized lymphadenopathy and from ten acquired immunodeficiency syndrome patients, all with serum antibodies to human T-cell leukemia virus III, were studied with regard to histopathology, immunohistology, and T-cell subsets in cell suspensions. All acquired immunodeficiency syndrome biopsies except one with Kaposi's sarcoma had the same histopathological pattern of follicular depletion, whereas the persistent generalized lymphadenopathy nodes showed a spectrum of changes characterized as follicular hyperplasia, involution with follicular fragmentation, or involution with follicular atrophy. Immunohistology showed a temporal and structural relation between follicular involution, disappearance of follicular dendritic reticulum cells, and follicular invasion by T-cells. These observations suggest elimination of dendritic reticulum cells as part of a pathogenic mechanism in follicular involution. Angiogenesis measured by staining of endothelial cells with antibodies to Factor VIII was increased in many biopsies in stages of involution and depletion. Our observations indicate the occurrence of marked changes not only in T-cells but also in the B-cell compartment of patients with persistent generalized lymphadenopathy or acquired immunodeficiency syndrome. The possibility of staging lymph nodes of these patients by combined histopathology and immunohistology is indicated. This might improve the evaluation of prognosis in these patients. A possible importance of angiogenesis for the tumorigenesis of Kaposi's sarcoma is suggested.

Acquired Immunodeficiency Syndrome↗

HTLV-III infection in homosexuals and hemophiliacs in Sweden.

Two hundred and three homosexual (HS) men and 114 hemophiliacs in Sweden were examined for serum antibodies to human T-lymphotropic virus type III (HTLV-III) and for alterations of T-lymphocyte subsets. Sera were screened for HTLV-III antibodies by an enzyme-linked immunosorbent assay and/or a dot immunobinding assay, and positive reactions were confirmed by Western blotting. HTLV-III antibodies were demonstrated in 13 of 13 (100%) HS men with acquired immune deficiency syndrome, in 63 of 67 (94%) HS men with persistent generalized lymphadenopathy, in 17 of 45 (38%) symptomatic HS men, and in 6 of 78 (8%) asymptomatic HS men but in none of 108 male blood donors. Seropositive HS men had significantly lower T4/T8 (helper/suppressor) cell ratios and T4 cell numbers than had seronegative HS men. Seronegative HS men had decreased T-cell ratios compared to controls but not decreased T4 cell numbers. Among hemophilia A patients, HTLV III antibodies were demonstrated in 40 of 48 (83%) cases treated with American factor VIII concentrate and in 17 of 29 (59%) cases treated with both American and Swedish concentrates but in none of 13 cases treated exclusively with Swedish factor VIII. Twenty-one hemophilia B patients treated with Swedish factor IX concentrates were all seronegative, whereas one of 3 hemophilia B cases treated with imported factor IX was seropositive. T4/T8 cell ratios were significantly lower in seropositive as compared to seronegative hemophilia A patients.

Acquired Immunodeficiency Syndrome↗

Reactivity of sera from patients with liver disease with glutaraldehyde-treated erythrocytes: role for false positive results in hemagglutination tests.

The use of glutaraldehyde as a coupling reagent in the passive hemagglutination test (HA) has gained wide application, especially for the coating of red blood cells (RBC) with glutaraldehyde-polymerized human serum albumin (pHSA), for studies of the albumin receptor on hepatitis B surface antigen (HBsAg) or for the detection of anti-albumin antibodies (AAA). Here we report a previously unrecognized reactivity with glutaraldehyde-treated RBC mainly with sera from patients with liver disease. The highest incidences of this reaction were found in patients with acute viral hepatitis A and B, namely 44 of 50 (88%) and 31 of 50 (62%) respectively. In 234 HBsAg carriers the frequency was low (3%). This reactivity was also observed in 19 of 50 sera from patients with chronic liver disease documented by biopsy, but not in sera from 68 healthy subjects. By immunofluorescence on glutaraldehyde-treated RBC it was shown that the corresponding antibodies belonged mainly to the IgM class. In all HBsAg-negative patients studied the HA titer against glutaraldehyde-treated RBC was in agreement with the titer against RBC coated with pHSA or pBSA (polymerized bovine serum albumin). Absorption with pHSA abolished the reaction with glutaraldehyde-treated RBC in 7 of 8 sera, suggesting a common reactivity between glutaraldehyde-polymerized HSA and glutaraldehyde-treated RBC. Apart from the possible clinical importance of these antibodies, their existence is a possible source of false positive results when glutaraldehyde is used as a coupling reagent for immunological assays, in particular with sera from patients with liver diseases.

Actins↗