No abstract

We identified the cytokines interleukin-1 beta (IL-1 beta), tumor necrosis factor (TNF), and interleukin-6 (IL-6) by specific radioimmunoassays in the CSF of patients with multiple sclerosis (MS) and other neurologic diseases (OND). There was a high incidence of detectable IL-1 beta in patients with active MS compared with inactive MS or OND patients. TNF was also more frequently present in active MS than in OND CSF. By contrast, most MS CSF did not contain detectable IL-6. There was no correlation between the degree of CSF pleocytosis and the level of individual cytokines, suggesting that cytokine accumulations may be derived from CNS, and not CSF, cells. As IL-1 beta and TNF experimentally induce astrogliosis, demyelination, temperature elevation, lassitude, and sleep, and results raise the possibility that these cytokines may contribute to a variety of manifestations in MS and in other disease states.

Inheritance of T cell receptor beta chain (TCR beta) genes was analyzed in families of 40 sibling pairs concordant for the relapsing-remitting form of multiple sclerosis (MS). TCR beta haplotypes were determined by segregation analysis of polymorphic markers within the TCR beta complex. The mean proportion of TCR beta haplotypes identical by descent (IBD) inherited by MS sibling pairs was significantly increased compared with expected values (means test, p less than 0.004), whereas the distribution of haplotype sharing was random when MS patients were compared with their unaffected siblings. Furthermore, one allelic form of a TCR beta variable region gene segment was overrepresented on MS chromosomes compared with those parental chromosomes not transmitted to MS offspring both in the MS sibling pair families and in a second group of families containing only one individual affected with MS. These results demonstrate that a gene within the TCR beta complex or a closely linked locus influences susceptibility to MS.

Several lines of evidence suggest that the anterior pituitary hormone prolactin has a stimulatory roIe on immune function and that pharmacological suppression of prolactin secretion with the dopamine-agonist bromocriptine suppresses both humoral and cellular immunity. Here, we describe the effects of prolactin-suppression on the course of experimental allergic encephalomyelitis in female Lewis rats. Initiation of continuous bromocriptine treatment before immunization reduced both the severity and incidence of clinical signs of acute experimental allergic encephalomyelitis. Experimental allergic encephalomyelitis-immunized rats experienced a threefold rise in basal prolactin levels on day 4 after immunization and maintained elevated prolactin levels on day 10, before the onset of neurological signs of experimental allergic encephalomyelitis. Bromocriptine treatment reduced prolactin levels to those of shamimmunized rats. In viva bromocriptine pretreatment inhibited splenic lymphocyte proliferative responses in vitro to the immunizing antigen and to concanavalin A. Moreover, bromocriptine therapy was protective when initiated 1 week after the initial immunization and w a s also effective in suppression of late disease. These results indicate that (1) prolactin levels are elevated after immunization and before the onset of experimental allergic encephalomyelitis, (2) bromocriptine inhibits both prolactin secretion and the severity of acute experimental allergic encephalomyelitis, and (3) inhibition is also present when treatment is begun after sensitization, suggesting an effect of prolactin on the effector limb of the immune response during experimental allergic encephalomyelitis.Riskind PN, Massacesi L, Doolittle TH, Hauser SL. The role of prolactin in autoimmune demyelination: suppression of experimental allergic encephaiomyelitis by bromocriptine. Ann Neurol 199 1; Prolactin (PRL), the major hormonal stimulus to lactation, is a 24-kd polypeptide hormone that is synthesized and secreted by the anterior pituitary gland. The importance of PRL to normal immune homeostasis was first shown by Nagy and Berczi 111, who found that hypophysectomized rats were severely immunocompromised, with profoundly depressed antibody titers to administered antigen and virtually absent delayed hypersensitivity responses. Surprisingly, in such animals, immunocompetence could be restored by exogenous PRL, and to a lesser extent by growth hormone, but not by other pituitary hormones 121. Later work demonstrated that bromocriptine (BCR), a dopaminergic agonist that selectively inhibits PRL release, mimics the effect of hypophysectomy {33. Treatment with PRL reversed the effect of BCR, indicating that its activity was due to specific inhibition of PRL release.Other studies indicated that excessive PRL levels maj7 stimulate immune responses. PRL treatment of normal mice resulted in a dose-dependent increase in splenic cell responses to mitogens such as concanavalin A (ConA) [4, S}. In rodent splenic lymphocytes, PRL also induced the expres...