Basal and IFN-gamma-induced DR expression on peripheral blood monocytes from multiple sclerosis patients. Preliminary data

185 TONSILLECTOMY AND BACTERIAL SERUM ANTIBODIES IN MULTIPLE SCLEROSIS PATIENTS: A CASE-CONTROL STUDY G r o n n i n g M, Nyland II, Ilillert J, Albrektsen G. Department of Neurology, University of Bergen, Norway. A population based case--contxolstudy of multiple sclerosis in I-Iordaland, Western Norway, included 155 patients with clinical onset during the years 1976-86 and 200 controls. "lV,e MS patients had lower serum anti-streptolysin titers (p<0.0001), but similar serum antibody titers to staphylococci and toxoplasmo6is. The serum concentration of IgG was higher in MS patients (p-0.002), while the IgA and lgM concentrations were lower (p-0.006 and p-0.007~ :CSl:eetively). The serum concentrations of complement factors C3, C4 and C3INI-I were lower in the MS patients (p<0.0001, p<0.0001 and p-0.003, respectively) No differences were observed between the relapsing-remittent and the chronic progressive cases, although immunogenetic differences existed, the haplotypc DRWI7,DQw2 was fivefold more common in the relapsing-remittent patients. In this population we have earlier found that tonsillectomy, especially in the age-group 0-6 years, was associated with increased risk of MS. When adjusted for age at tonsillectomy, the differe, lces between cases and controls in IgA, IgM and C3INH serum concenU'ations, were no longer significant. Accordingly, age at tonsillectomy may explain some of the immune abnormalities seen m our MS popu!ation.

BASAL AND IFN-GAMMA-INDUCED DR EXPRESSION ON PERIPHERAL BLOOD MONOCYTES FROM MULTIPLE SCLEROSIS PATIElqTS. PRELIMINARY D A T A M.Eoli, A.Salmaggi, E.Ciusani, L.La Mantia, C.Milanese Istituto Nenrologico ~C.Besta" Via Celoria 11-20133 Milan Italy Monocytes play a pivotal role in the immune response as antigen-presenting cells (APCs). The amount of surface DR antigen, as well as its increased expression after IFN -gamma stimulation, are critical factors in the immune reactions, and the study of these parameters may provide insight into pathogenetic mechanisms in autoimmune diseases, such as experimental allergic encephalomyelitis and, possibly, multiple sclerosis (MS). Baxevanis (1989) has reported a decreased amount of DR on peripheral blood (PB) monocytes from MS patients with active disease in comparison with unactive patients and controls. Armstrong (1990) has obtained data at variance with Baxevanis. We have therefore studied by flow cytometry both baseline and IFN-gamma-induced (after 18 and 24 hours) DR expression, as assessed by Median channel fluorescence values, on PB monocytes (isolated by Percoli ~Iradient and stimulated in culture with recombinant IFNgamma) from 6 healthy controls and 7 patients with clinically active MS. Our preliminary data do not show any difference between patients and controls in basal DR expression. In agreement with Armstrong's results, DR expression increase took place both in IF-treated and in non-IFN-treated monocytes after 18 and 24 hours in culture. However, this increase was more marked in IFN-gamma-treated monocytes. MS monocytes showed a more prolonged expression of DR after IFN-gamma stimulation in comparison with controls. The data are discussed in view of the possible pathogenetic significance.