CSF oligoclonal band frequency in a Cuban cohort of patients with multiple sclerosis. comparison with Latin American countries and association with latitude

Abstract

Background: The diagnostic sensitivity of CSF specific oligoclonal bands (OCBs) in multiple sclerosis (MS), using state of the art methods, has been clearly established to be over 95% in patients with a predominantly Caucasian background. This is not the case for other geographical regions, where reports of OCB prevalence can be much lower, and a relationship between OCB frequency and latitude has been suggested.

Objective: The aim of the present study was to assess the frequency of OCBs in a cohort of MS patients evaluated at the Institute of Neurology and Neurosurgery (Havana, Cuba), and to review the scientific literature in order to investigate the possible relationship between OCB status and latitude in the region of Latin America.

Methods: Fifty-three patients (47 with definite MS and 6 with clinically isolated syndrome - CIS) were included. Isoelectric focusing (IEF) with IgG immunoblotting for OCB analyses, was performed placing paired CSF and serum samples in the same analytical run. PubMed, Scielo and Google Scholar were searched for papers containing information concerning CSF OCB status (employing isoelectric focusing with IgG immunoblotting) in patients with definite MS in Latin America and the Caribbean.

Results: In Cuban patients with definite MS, an OCB prevalence of 87% was observed, while the frequency in CIS patients was lower (67%). The prevailing pattern was that of OCBs restricted to the CSF (type 2), which was observed in 71% of definite MS patients and in all CIS patients with intrathecal IgG synthesis. OCB prevalence was slightly lower, but very close to that reported in Caucasian populations. Comparison with other Latin American countries revealed a significant correlation between OCB prevalence and latitude.

Conclusions: A prevalence of CSF restricted OCBs of 87% was observed in definite MS patients, a frequency which was slightly lower, but similar to that reported in Caucasian populations. The analysis of OCB frequency in Latin American countries revealed a possible relationship between OCB prevalence and latitude, but this must be further investigated in more countries and larger samples of patients.

Keywords: Cuba; Intrathecal IgG synthesis; Latin America; Latitude; Multiple sclerosis; Oligoclonal bands.