Susan Hoch

Frequency of anti-DNA antibody producing cells from normals and patients with systemic lupus erythematosus

The frequency of anti-DNA antibody producing cells from normals and patients with systemic lupus erythematosus (SLE) was determined. Peripheral blood lymphocytes (PBL) from normals and patients with SLE were cultured for 8 and 15 days with and without transformation by Epstein-Barr virus (EBV). Culture supernatants were examined for the presence of anti-DNA antibody using an enzyme-linked immunosorbent assay. We found that PBL from patients with SLE spontaneously produce anti-DNA antibodies whereas PBL from normals do not. After EBV transformation, anti-DNA antibody producing cells were detected in both cultures from patients with SLE as well as from normals. These data suggest that the high levels of anti-DNA antibody observed in patients with SLE represent activation of B cells committed to anti-DNA antibody production and that such cells are present but are not activated in normal individuals.

The timing of menarche in juvenile rheumatoid arthritis

A study of the age of menarche in juvenile rheumatoid arthritis (JRA) patients was undertaken to determine what factors affect the timing of menarche. There was a significant difference between the mean age of menarche for the 68 JRA patients and 46 controls (p = 0.015). No clear etiology for this difference was elucidated. Polyarticular-onset JRA patients had the oldest age of menarche, but this finding was of marginal statistical significance (p less than 0.05,pcorr less than 0.25). The multivariate model that included onset type, steroid use, and duration of disease weakly predicted age of menarche in the JRA group. This model suggests that, exclusive of height and weight parameters, duration of disease was the most important predictor of menarche in JRA.

Characterization of the Polymerase Activity Associated with Cultured Peripheral Blood Mononuclear Cells from Patients with Kawasaki Disease

ABSTRACT: The particulate fractions of culture supernatants from peripheral blood mononuclear cells from 39 patients with Kawasaki disease (KD) were examined for the presence of particle-associated reverse transcriptase activity. The peak polymerase activity was significantly higher in cultures from KD patients compared to controls (mean = 6.4 versus 3.6 pmol of dTMP incorporated, p = 0.001). PBMC cultured between the 3rd and 9th wk after onset of fever were most likely to be associated with reverse transcriptase activity. Peak polymerase activity was positively associated with older age (r = 0.41, p = 0.01) and greater magnitude of the serum IgA response at 7-14 d after onset of fever (r = 0.45, p = 0.01) and IgM response at 6-9 wk after onset of fever (r = 0.46, p = 0.01). The appearance of enzyme activity was not associated with a decrease in viability of the cultured cells. A purified enzyme preparation showed radiolabel incorporation only with an RNA template with DNA primer. These data suggest that circulating mononuclear cells from KD patients may harbor a polymerase-associated agent and that these cells can be most readily detected in the early convalescent phase of KD from older patients who mount a marked humoral immune response.

Monocyte bone degradation: in vitro analysis of monocyte activity in patients with juvenile rheumatoid arthritis.

We examined the ability of the mononuclear phagocyte in vitro to degrade 45Ca-labeled bone particles to determine whether this assay allowed us to monitor disease activity in patients with juvenile rheumatoid arthritis. The monocytes from patients with juvenile rheumatoid arthritis receiving no anti-erosive therapy (n = 10) degraded significantly more bone than did cells obtained from normal controls (n = 10, P less than 0.001) or patients with juvenile rheumatoid arthritis receiving either gold thioglucose (n = 4, P less than 0.001) or D-penicillamine (n = 6, P less than 0.005). In two patients monitored for either 8 or 11 months, results of monocyte assays were found to parallel the clinical course. We conclude that in vitro monocyte bone degradation assays may provide a means of assessing joint activity in patients with juvenile rheumatoid arthritis. Further, this study and others indicate that mononuclear phagocytes are capable of causing erosive changes.

Improved method for cloning human B-cell lines

Abstract Difficulties in the successful cloning of B-cell lines have prevented widespread establishment of specific antibody-forming human B-cell lines. We have improved on standard methods of cloning by culturing human lymphoid cells suspended in agarose with nonproliferating human fetal lung fibroblasts. Using this method, cloning efficiencies up to 20% were observed, from as few as 50 plated lymphoid cells. These results are significantly better than the efficiencies of up to 1% using 5 to 10 × 10 3 cells with traditional soft agar methods. The number of colonies observed increased in proportion to the number of fibroblasts plated with the lymphoid cells. A threshold number of fibroblasts was found. Microscopically, close association between lymphoid cells and fibroblasts was seen. A growth-enhancing factor appears to be produced by fibroblasts suspended in agarose. This cloning method is applicable to both well-established and newly established lymphoid cell lines and should be useful for growing and cloning B cells.