Highly Polymorphic Domains of the Human Serum Amyloid A (SAA) Gene GSAA1

The DNA of the human serum amyloid A (SAA) gene GSAA1 contains several repetitive regions within its introns. We have studied length variations at one such region in the 2nd intron by selective amplification using the polymerase chain reaction (PCR) and defined oligonucleotide primers. The lengths of the repetitive regions frequently differ between individual chromosomes and can be transmitted as Mendelian markers, making them useful for genetic linkage analysis.     

Heart rate reactivity and heart period variability throughout the first year after heart transplantation

Heart rate reactivity to mental stress is substantially blunted early after heart transplantation, suggesting that the loss of neural modulation limits the cardiovascular response to mental stress. We tested whether reactivity to mental stress recovers during the first year after heart transplantation. Hemodynamic and respiratory responses to mental arithmetic challenge were studied in 20 heart transplant recipients 3, 6, and 12 months after surgery. A normal comparison group was studied at equivalent intervals. Heart rate reactivity to mental arithmetic was significantly reduced in the cardiac transplant group compared to the normal subjects. This effect persisted up to 1 year after transplantation. Heart period variability in the heart transplant recipients was minimal in all three-test sessions. The findings suggest that no functional reinnervation or other compensatory adaptation occurs up to 1 year after heart transplantation.     

Studies of Antibody to Herpes Simplex Virus Fcγ-Binding Protein gE in Patients with Rheumatoid Arthritis, Juvenile Rheumatoid Arthritis and Normal Controls

IgG antibody to gE, the Fc gamma-binding herpes simplex 1 (HSV-1) viral glycoprotein, was studied in 49 rheumatoid arthritis (RA) patients and 43 normal controls. Antibody to gD, another important HSV-1 antigen, was assayed in parallel. No difference between RA patients and normal controls was found in levels of anti-gE antibody measured by reactivity of IgG F(ab')2 fragments reacting with gE coated to ELISA plates. No difference in anti-gD antibody was recorded between normals and patients with RA. Levels of IgG anti-IgE antibody did not correlate with quantitative elevations of serum rheumatoid factor (RF) in RA patients. When IgG anti-gE and anti-gD were assayed in 20 patients with juvenile rheumatoid arthritis and 22 children controls, no significant differences were noted. However, when individual RFs from patients with RA were tested for reactivity against a panel of affinity-isolated F(ab')2 antibodies to gE, some evidence for individual autospecificity was obtained. Four of 20 monoclonal IgM RFs produced from RA patients' B cells showed marked elevations of reactivity with some RA patients' F(ab')2 antibodies to gE. All four of the monoclonal RFs showing this specificity were derived from RA synovial tissue B cells. These findings may provide support for the concept that some RFs in patients with RA show individual specificity for internal image determinants of IgG antibodies to viral Fc gamma-binding proteins.     

IgG human monoclonal anti-DNA autoantibodies from patients with systemic lupus erythematosus

We describe the production of six mouse-human heterohybridomas secreting human IgG anti-dsDNA antibodies derived from patients with systemic lupus erythematosus (SLE). Peripheral blood cells used for fusion experiments were from patients who were shown to have high numbers of anti-DNA secreting B cells in the peripheral blood. All monoclonal antibodies bind to dsDNA in ELISA systems, five are reactive with Crithidia lucilae kinetoplasts and three precipitate dsDNA in the Farr assay. Inhibition studies revealed a remarkable specificity for certain polynucleotide structures. To our knowledge these are the first hybridomas described in the human system that secrete anti-dsDNA antibodies of the IgG class.     

Characterization of monocyte-derived dendritic cells in recent-onset diabetes mellitus type 1

Dendritic cells (DC) may play an important role in the immunopathogenesis of type 1 diabetes mellitus (DM-1). In this study, we have analyzed phenotypical changes during cytokine-driven maturation from CD14+ monocytes to mature DC and DC-dependent T-cell stimulation in recent-onset pediatric DM-1 patients and healthy controls. DC maturation was monitored by flow cytometric analyses for the expression of surface markers (HLA-DR, CD1a, CD40, CD80, CD86, CD83, CD14, CD32, mannose-receptor, and CD11c). Flow cytometric analysis of isolated peripheral blood monocytes did not reveal apparent differences between patients and controls. During DC maturation no obvious differences in the expression patterns of surface markers over time or evidence for maturation impairments in DM-1 patients could be appreciated. Solely, a marginal, but significant, transient down-regulation of CD1a on Day 3 (mean MDFI 3.82 vs 7.25; P = 0.021), which was accompanied by an increase of IL-6, could be observed. The comparison of mature DCs (Day 10) between patients and controls indicated no significant differences, except for CD83 (mean MDFI 1.7 vs 1.5; P = 0.042) and CD80 (mean MDFI 15.92 vs 12.73; P = 0.042). Moreover, no difference in T-cell stimulatory capacity was seen. In conclusion, our analysis of a cohort of recent-onset DM-1 patients and controls does not support a role for disease-related alterations in cytokine-driven maturation of monocyte-derived DC.     

Human anti-mouse antibody response induced by anti-CD4 monoclonal antibody therapy in patients with rheumatoid arthritis

The development of human anti-mouse monoclonal antibodies (HAMAs) was investigated in 10 patients with rheumatoid arthritis (RA) who had undergone an experimental therapeutic trial with an anti-CD4 monoclonal antibody. In this patient group, the antibody 16H5 of the IgG1 isotype had been administered in a median total dosage of 140 mg per treatment cycle. Four patients took part in a second treatment regimen 6-8 weeks later. After the first treatment cycle, detectable HAMAs developed in 5 out of 10 patients. In 4 individuals undergoing a second course of therapy, increases of HAMAs were evident only in the 3 patients with previous HAMA responses. HAMAs were primarily of the IgG isotype, while the presence of rheumatoid factors usually interfered with the detectability of IgM HAMAs. However, using isolated F(ab)2 fragments of the monoclonal reagent used for therapy, HAMAs of the IgM isotype were also detectable. HAMAs of the IgG isotype did not exceed levels of 2.0 mg/liter after a single treatment cycle and 2.2 mg/liter after a repeated cycle. No IgE responses were detectable. Absorption experiments indicated that approximately 25% of the HAMA activity was directed against specific determinants of the 16H5 monoclonal antibody, presumably including anti-idiotypic reactivities. These data demonstrate that HAMAs developed only in a proportion of RA patients treated with the anti-CD4 monoclonal antibody 16H5. However, the amounts were rather low compared to other monoclonal reagents used in cancer patients and were therefore allowed for repeated applications without an apparent loss of efficacy.     

The Binding of Different Lectins on Peripheral Blood Mononuclear Cells from Patients with Chronic Inflammatory and Malignant Diseases

Peripheral blood mononuclear cells from patients with multiple myeloma, gastrointestinal tumors, and inflammatory bowel disease were analyzed for binding of various lectins. The results demonstrated that in most of the patients with multiple myeloma a significantly increased percentage of cells positive for Lotus tetragonolobus agglutinin (LTA), peanut agglutinin (PNA), soybean agglutinin (SBA), and wheat germ agglutinin (WGA), and a decreased number of Agaricus bisporus agglutinin (ABA) positive cells were present as compared to a normal control group. This could not be shown in malignant or inflammatory disorders of the gastrointestinal tract where only some patients exhibited an increased PNA and LTA binding, respectively. Patients with the systemic malignant disease differed from patients with solid localized tumors by a significantly altered number of ABA, LTA and SBA-positive peripheral blood mononuclear cells. Double fluorescence studies using monoclonal antibodies and lectins revealed that most of the cells expressing receptors for ABA had also receptors for OKT3, whereas most of the cells with receptors for LTA, PNA SBA, and WGA were found to be positive for OKM.