Ninety children with definite juvenile dermatomyositis (JDMS), who had been HLA typed, were tested for the presence of tissue or organ‐specific antibodies. Sixty had active disease at the time of study. The mean disease duration was 4 years, and 30 had soft tissue calcifications. The following autoantibodies were sought: thyroid, gastric parietal cells, smooth muscle, striated muscle, microsomes, mitochondria, DNA, extractable nuclear antigen, Sm, PM‐1, antinuclear antibody (ANA), and rheumatoid factor. Only the ANA and PM‐1 were more frequent in patients than in controls (P < 0.0002 and P < 0.001, respectively). Higher levels of immune complexes (P < 0.01) were found in sera from patients with JDMS than in sera from controls and were correlated with the presence of ANA in patients (P < 0.01). Soft tissue calcification was not associated with any autoantibody or HLA antigen, but with disease duration and activity (P < 0.001 and P < 0.05, respectively). There was no association between the occurrence of any autoantibody and the presence of HLA‐B8 or DR3 among the white patients with JDMS. The frequency of autoantibodies in 43 full siblings of children with JDMS was not increased. We conclude that children with JDMS, with or without HLA‐B8/DR3, do not show evidence of a generalized nonspecific antibody response to tissue antigens. The significance of the increased antibody to nuclear antigens ANA and PM‐1 remains to be determined.

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Defectsdin th: AP o J complement a r e thought t o pjay a r o l e in t h e s u s c e p t i b i l i t y of newborns (NB) t o infection. The CL assay was used t o measure the a b i l i t y of varying quantities of 20 cord sera t o opsonize zymosan (Z). Concentrations of AP componentswere correlated with CL and outcome. Luminol enhanced CL was performed using adult polymorphonuclear leukocytes t o r e a c t with the opsonized Z. The cord sera was found t o contain 30-70% of normal concentrations of C3, f a c t o r B , properdin, BlH, and C3bINA. Mean opsonization a s measured by CI. was decreased f o r cord sera when compared t o controls; however, some NB sera demonstrated normal a b i l i t y t o opsonize Z. Opsonic a c t i v i t y varied s i g n i f icantly only with the B1H concentration of the serum. BlH, along with C3bINA, i s known t o regulate the a c t i v i t y of C3 and factor B i n the AP so t h a t the r a t i o of C3+factor B/BlH+CJbINA in non-NB's i s approximately 1.0. In the cord sera of 200 uninfected NB's, however, t h i s r a t i o was 1 . 3 (p < 0.001) suggesting an a l t e r e d regulatory mechanism f o r the normal NB. Eight of 9 NB' s who experienced systemic infection i n the f i r s t few days of l i f e had a r a t i o of AP components equivalent t o the non-NB's. These data demonstrate t h a t f a i l u r e t o develop a typical neonatal regulatory pattern may play a r o l e in defective opsonic a c t i v i t y and t h a t CL may be used t o study t h i s a c t i v i t y in NB sera. The a b i l i t y of NB s e r a t o opsonize Z , however, does not predict sus- Speoific antibody responses in v i t r o can be induced in t h e peripheral blood mononuclear c e l l s (PBMC) of >go% of normal individuals by stimulation with type A influenza viruses. Cumulative antibody synthesis is measured in 12 day culture supernatants by ELISA methodology. Antibody production requires t h e cooperative interaction of B-cells. T-cells, and monocytes. Antibody is expressed in u n i t s (U), 1 U being the amount of antibody present i n a 1/105 d i l u t i o n of a pooled reference serum (approximately 2.2 ng of IgG antibody). PBMC from only 1 of 5 A-T p a t i e n t s made measurable antibody; t h i s one patient made 0.7 U/ml. This is oonsiderably l e s s than t h a t produced by PBMC from 6 parents of A-T p a t i e n t s (13.6 2 7.7, mean 2 SEM) or 14 normal controls (19.1 + 5.5). Further studies were undertaken t o examine t h e mechanism -o f non-responsiveness i n 2 patients. The f i r s t p a t i e n t ' s PBMC produced antibody when co-cultured with purified, irradiated, allogeneio T-cells and t h e second p a t i e n t ' s purified & c e l l s produoed antibody when stimulated with Epstein-Barr virus. Thus both p a t i e n t s had B-cells which could be stimulated t o produce speoific antibody. Functional monocytes were a l s o demonstrated i n t h e second patient since h i s i r r a d i a t e d , adherent c e l l s recons t i t u t e d antibody production by c u l t u r e s of monooyte-depleted PBMC ...