Autoreactivity to myelin antigens: myelin/oligodendrocyte glycoprotein is a prevalent autoantigen.

Autoreactive T cells specific for myelin antigens are thought to play a role in the pathogenesis of multiple sclerosis (MS). We compared T cell proliferative responses in peripheral blood following challenge in vitro with myelin/oligodendrocyte glycoprotein (recombinant protein, rMOG), myelin basic protein (MBP) and proteolipid apoprotein (PLP) in 50 patients with MS and 40 healthy controls. T cell reactivity against rMOG (defined by a specific stimulation index of 2.5 or greater) was present in 13 (26%) MS patients and 12 (30%) healthy controls and was MHC-restricted, as anti-MHC class II antibodies abolished all proliferative responses. By contrast, reactivity against PLP was present in only one (2%) MS patient and six (15%) controls, and no reactivity against MBP was found in any subject. Thus, by the criteria of the present study, an increased reactivity of circulating T cells to MOG is present to a similar degree in healthy individuals and in patients with MS. This finding raises the possibility that additional factors contribute to the pathogenicity of these autoreactive T cell populations in demyelinating disorders of the central nervous system.

Gangliosides do not elicit experimental autoimmune encephalomyelitis in Lewis rats and SJL mice.

We have studied the ability of gangliosides to induce or ameliorate experimental autoimmune encephalomyelitis (EAE) in Lewis rat and SJL mice. None of the animals immunized with gangliosides with or without methylated bovine serum albumin (MBSA) developed EAE. Gangliosides were also administered simultaneously with PLP, but they did not alter the incidence or severity of EAE. However, high doses of MBSA could ameliorate or prevent EAE in a dose-dependent manner. T-cell responses towards gangliosides and antiganglioside antibodies were also studied. In conclusion, in these experimental models gangliosides have no encephalitogenic activity and do not alter the course of EAE.

Jun expression is found in neurons located in the vicinity of subacute plaques in patients with multiple sclerosis.

The expression of members of the Fos and Jun families is examined by immunohistochemistry in the brains of two patients with multiple sclerosis (MS). Strong c-Jun immunoreactivity is observed in the cytoplasm of neurons located in the vicinity of subacute plaques, but not in neurons of brain compartments not compromised by MS and in the neighborhood of chronic plaques. Strong c-Jun immunoreactivity also contrast with weak c-Jun immunoreactivity of corresponding neurons in control brains. In addition, punctate Jun D immunoreactivity is observed in the neuropil of the same areas that express c-Jun. No immunoreaction is found to c-Fos, Fos-related antigens and Jun B in these areas. The present results suggest that selective Jun neuronal expression in the vicinity of subacute plaques is a consistent reaction to demyelination and axonal damage.

Isolated demyelinating syndromes: comparison of different MR imaging criteria to predict conversion to clinically definite multiple sclerosis.

BACKGROUND AND PURPOSE: Various authors have developed criteria to classify MR imaging findings that suggest the possibility of multiple sclerosis. The purpose of this study was to evaluate and compare the capacity of three sets of MR imaging criteria for predicting the conversion of isolated demyelinating syndromes to clinically definite multiple sclerosis. METHODS: Seventy patients with clinically isolated neurologic symptoms suggestive of multiple sclerosis were prospectively studied with MR imaging. The MR imaging findings were evaluated by two independent neuroradiologists who were blinded to clinical follow-up data. Based on the clinical outcome at follow-up (presence of a second attack that established clinically definite multiple sclerosis), the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the criteria proposed by Paty et al, Fazekas et al, and Barkhof et al were calculated. RESULTS: Clinically definite multiple sclerosis developed in 22 (31%) patients after a mean follow-up time of 28.3 months. The criteria proposed by Paty et al and those proposed by Fazekas et al showed identical results: sensitivity, 86%; specificity, 54%; accuracy, 64%; positive predictive value, 46%; and negative predictive value, 89%. The criteria proposed by Barkhof et al showed the following: sensitivity, 73%; specificity, 73%; accuracy, 73%; positive predictive value, 55%; and negative predictive value, 85%. CONCLUSION: The four dichotomized MR imaging parameters proposed by Barkhof et al are more specific and accurate than the criteria proposed by Paty et al or Fazekas et al for predicting conversion to clinically definite multiple sclerosis.

[Transient cerebral and bone marrow ischemia in patients with atrioseptal aneurysm]. / Isquemia cerebral y medular transitoria en pacientes con aneurisma atrioseptal.

The relationship between atrioseptal aneurysm and ischemic stroke has not been clearly demonstrated. We present three patients with transient cerebrovascular events and one patient with transient medullar ischemia related with the presence of atrioseptal aneurysm. Other causes of cerebrovascular disease have been excluded. Following anticoagulation treatment all the patients remain asymptomatic.

Chronic inflammatory diseases of the nervous system.

In many neurologic diseases, activated leukocytes enter the nervous system and initiate a chronic inflammatory process. Understanding how the cellular and humoral responses are associated with pathogenesis is essential for the formulation of a unifying model of central and peripheral nervous system inflammation. Based on such a model, immunotherapeutic strategies and protocols can be designed.

[Syphilitic meningoradiculitis in a patient with HIV]. / Meningorradiculitis sifilítica en paciente con infección por el virus de la inmunodeficiencia humana.

Meningoradiculitis is a rare presentation of neurosyphilis. In patients infected by human immunodeficiency virus (HIV), the first diagnosis to consider is cytomegaloviral (CMV) infection, as this is the most common cause of meningoradiculitis in these patients. The course of the disease and its response to treatment is highly influenced by immunodepression. We present an HIV+ patient with clinical meningoradiculitis due to syphilis.