Prostaglandins and cyclic nucleotides in the Chédiak-Higashi syndrome and experimental systemic lupus erythematosus

Inhibition by various antiarthritic agents of murine splenic B cell colony formation

There is accumulated evidence suggesting that a polyclonal B cell activation is a primary etiologic defect of autoimmune diseases in both mice and humans. Based on this previous finding, the influence of various antiarthritic agents on lipopolysaccharide-induced B cell colony formation in mouse spleen cells was studied. When added to cell culture, aurothioglucose, chloroquine, and prostaglandin E1 had a suppressive effect on B cell colony formation at clinically relevant concentrations. A 50% suppression was obtained at 10(-7) to 10(-8) M for aurothioglucose, 10(-7) M for chloroquine, and 10(-7) to 10(-8) M for prostaglandin E1, respectively. All of the immunosuppressive drugs and glucocorticoids examined decreased the number of colonies with a variety of intensity. Nonsteroidal antiinflammatory drugs have only a slight inhibitory effect at high concentrations. Both penicillamine and levamisole had no effect on B cell colony formation. This experimental system might be useful in searching for new and unique drugs and in evaluating the mode of action of drugs used against autoimmune diseases.

Atypical lymphadenopathies of the head and neck

Atypical lymphadenopathies fail to achieve the morphologic criteria of a malignant neoplasm, but exceed the usual concepts of follicular, lymphoid, or sinus histiocytic hyperplasias. Rich cellular proliferations usually composed of prominent histiocytes, or immunoblasts, or both with or without a vascular scaffolding obscure the nodal architecture. Toxoplasmosis, infectious mononucleosis, zoster, and vaccination-induced lymphadenopathies are caused by infectious agents, dermatopathic lymphadenitis is associated with cutaneous disease, anticonvulsant pseudolymphoma occurs in individuals hypersensitive to anticonvulsants (usually phenytoin), and Chediak-Higashi syndrome is an inherited abnormality of lysosomal microtubule function; the causes of sinus histiocytosis with massive lymphadenopathy, giant lymph node hyperplasia, angioimmunoblastic lymphadenopathy, mucocutaneous lymph node syndrome, and this histiocytoses remain unknown. The clinical course of these abnormalities varies from self-limited acute diseases (viral lymphadenopathies, toxoplasmosis, dermatopathic lymphadenitis, and usually anticonvulsive lymphadenopathy) to protracted, but benign abnormalities (sinus histiocytes with massive lymphadenopathy, giant lymph node hyperplasia, and multifocal eosinophilic granuloma). The diagnosis of angioimmunoblastic lymphadenopathy, Chediak-Higashi syndrome, and mucocutaneous lymph node syndrome necessitates a guarded prognosis, for death or the advent of a malignant lymphoma may interrupt their clinical course. Acute disseminated histiocytosis, even though the proliferated cell lacks the cytologic criteria of malignancy, should be regarded and treated as a malignant neoplasm.

Differential regulation of the formation of prostaglandins and related substances from arachidonic acid and from dihomogammalinolenic acid. II. Effects of vitamin C

Vitamin C over the concentration range 10 to 100 microgram/ml (5.7-57 x 10-5 M) caused a dose dependent and highly significant enhancement of conversion of 14C-dihomogammalinolenic acid (DGLA) to prostaglandin (PG) E1 and to thromboxane (Tx) B1 by human platelets. Vitamin C had no effect on conversion of 14C-arachidonic acid to PGE2 and TxB2. The concentration range is relevant to physiology: in some cells which concentrate the vitamin, such as polymorphonbuclear leucocytes and the adrenal cortex, vitamin C concentrations may be substantially higher than 100 microgram/ml. Vitamin C can therefore selectively enhance the formation of cyclo-oxygenase generated products from DGLA without changing formation of those from AA. This effect can account for a number of the known actions of vitamin C including its effect on the immune system. The implications of this finding are discussed.