A clinical, serological, and histopathological study of myositis patients with and without anti-RNP antibodies.

Twenty-nine patients with myositis, including 10 with polymyositis (PM), 6 with dermatomyositis (DM), and 13 with myositis associated with a connective tissue disease (CTD), were followed up for a mean observation time of 49 months. The 13 patients with CTD-associated myositis were further separated by the presence or absence of anti-RNP antibodies. The functional disability at diagnosis was pronounced without differences between the groups. The patients with anti-RNP antibodies did not differ from the other patients regarding initial muscle weakness, erythrocyte sedimentation rate, or creatinine phosphokinase values, but the histopathological muscle changes were generally milder. Rapid improvement of muscle strength on moderate doses of corticosteroids was seen in most patients. At the end of study, corticosteroid treatment had been withdrawn from 17 patients because of remission, including 6 of the 7 patients with anti-RNP antibodies. The presence of electromyographic changes compatible with myositis, pronounced muscle weakness before treatment, and a low erythrocyte sedimentation rate seemed to indicate a less favorable outcome unrelated to diagnostic subgroupings. However, the combination was rarely found among the anti-RNP-positive patients.

Characterization of peripheral blood lymphocytes in sarcoidosis.

In the basal state, patients with sarcoidosis have reduced numbers of circulating T lymphocytes and a normal number of circulating B lymphocytes. The lymphocytes show impaired DNA synthesis in response to several mitogens and antigens and impaired K-cell cytotoxicity. Circulating atypical cells of lymphocytic origin are present belonging to both T- and B-cell lineages. After work (with mobilization of lymphocytes) the T-cell deficiency is further accentuated compared with normals. Moreover, after work a deficiency in the number of circulating B cells is also encountered. The atypical cells do not increase. Compared with normals the impaired K-cell cytotoxicity and lower levels of DNA synthesis also persist. It is suggested that the deviations found in sarcoidosis are consequences of a disease process affecting the lymphoid tissues and successively replacing the normal structures. The presence in vivo of DNA-synthesizing circulating lymphocytes may indicate a persistent antigenic stimulation.

Studies on the specificity of the immunohistopathological changes of the salivary glands in Sjögren's syndrome.

Recently focal lip salivary gland lymphocytic infiltrates, identical to those found in Sjögren's syndrome, has been described in myasthenia gravis, bone marrow transplant recipients and various connective tissue diseases, in the latter conditions without relation to the salivary gland function. In the bone marrow transplant recipients, the lymphocytic infiltrates were shown to be potentially reversible. The findings are summarized, the relation between histopathological alterations and organ functions and the diagnostic specificity of focal lymphocytic infiltrates in lip salivary glands are discussed.

Immunological aspects of sarcoidosis.

Circulating immune complexes were found in sera from patients with acute sarcoidosis during the initial phase of the disease. The symptoms of acute sarcoidosis may be explained by the presence of such complexes. The total number of peripheral T cells was lower in most patients with sarcoidosis than in healthy controls. The difference was most marked in cases with long duration of the disease. The composition of peripheral T cells was altered irrespective of the total number of such cells, and a lack of cells responding to PPD and con A was shown. Tis may be related to the impairment of delayed hypersensitivity reactions which may be present in all stages of the disease. The atypical mononuclear cells which have been found in blood from patients with sarcoidosis are lymphocytic cells. Some have B cell properties whereas some seem to have T cell origin. The presence of such cells may indicate a persistent activation of the immune system. Immunological reactivity determined by genes closely linked to the major histocompatibility complex does not seem to be responsible for susceptibility to sarcoidosis.