Elevated D8/17 expression on B lymphocytes, a marker of rheumatic fever, measured with flow cytometry in tic disorder patients.

OBJECTIVE: Elevated D8/17 expression on B lymphocytes is a known susceptibility marker of rheumatic fever. Previous studies have reported higher than usual D8/17 expression on B lymphocytes of patients with tic disorders. The purpose of this study was to assess D8/17 expression on B lymphocytes of tic disorder patients by using an objective method in which no operator variability was involved. METHOD: D8/17 expression on B lymphocytes was assessed with flow cytometry by using an immunoglobulin M (IgM) monoclonal D8/17-specific antibody in an unselected group of Dutch patients with tic disorders (N=33) and healthy volunteers (N=20). Binding of this monoclonal antibody was compared with binding of an irrelevant IgM monoclonal antibody, and the shift in mean fluorescence intensity of the D8/17-specific antibody compared to that of the irrelevant IgM monoclonal antibody was used as a measure of D8/17 overexpression. For the patients, Yale Global Tic Severity Scale scores were used to assess disease severity. RESULTS: D8/17 overexpression in the patient group (mean=16.8 arbitrary units, SD=30.5) was significantly higher than in the comparison group (mean=3.2, SD=3.0). A significant minority of the patients (N=13, 39.4%), however, had levels of D8/17 overexpression within the range of that of the healthy comparison subjects. Flow cytometric analysis did not indicate a separate subpopulation of D8/17-positive B cells. CONCLUSIONS: These data confirm the utility of D8/17 B cell overexpression as a peripheral blood marker in patients with tic disorders and are compatible with a streptococcus-related pathogenesis for at least a subgroup of patients with tic disorders.

The 'metabolic burst' in polymorphonuclear leukocytes from patients with quiescent psoriasis.

We report an investigation of peripheral blood polymorphonuclear leukocytes (PMN) from untreated patients with mild, quiescent psoriasis. Four aspects of the 'metabolic burst' were measured to illustrate phagocytosis-related events. These were: myeloperoxidase activity, hydrogen peroxide release, superoxide production and luminol-amplified chemiluminescence. Our study does not support the concept of an intrinsic abnormality of the PMN in psoriasis, but provides additional evidence for disease activity-dependent changes in phagocytic behaviour. Possible interactions with certain humoral factors, the so-called opsonins, are discussed.