Application of the McDonald 2010 criteria for the diagnosis of multiple sclerosis in an Argentinean cohort of patients with clinically isolated syndromes

Background:

The International Panel on Diagnosis of Multiple Sclerosis has proposed new magnetic resonance imaging (MRI) criteria for the diagnosis of multiple sclerosis (MS) in patients with clinically isolated syndrome (CIS). We aimed to evaluate these new criteria in a cohort of patients from Buenos Aires, Argentina.

Methods:

Patients with CIS, in whom MRI was performed within three months of onset of symptoms, were included between January 2005–June 2010. Poser or McDonald 2005 criteria were used as gold standard diagnostic criteria for MS. MRI was assessed by a blind evaluator identifying recently diagnostic MS criteria. New criteria sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were determined.

Results:

Altogether 101 patients were included. Of these, 86 patients converted to MS (McDonald 2005/Poser) during the follow-up. The mean follow-up time was 7.3±3.2 years (range 1.8–11 years). Sensitivity was 84%, specificity 80%, PPV 96%, NPV 46% and accuracy 82%. The sub-analysis applied only to non-European descendants (mestizos, natives and zambos) showed a high level of accuracy for these new diagnostic criteria in this local ethnic/genetic population (sensitivity 77%, specificity 72%, PPV 94%, NPV 38%).

Conclusions:

This study assessing McDonald 2010 criteria in a Latin-American population may contribute to its international validation.

[LACTRIMS consensus document for the pharmacological treatment of the multiple sclerosis and its clinical variants]

INTRODUCTION. Multiple sclerosis (MS) it is not considered any more a rare disease in Latin America. Most of the Latin American countries have reported moderate or lower prevalence data. However only very few countries have developed therapeutic guidelines. LACTRIMS prepared this consensus document with specific recommendations for the treatment of the disease. DEVELOPMENT. Experts on treatment and clinical research on MS were invited by LACTRIMS in order to generate a initial document to be discussed in Quito, Ecuador. Several groups were organized in relation of the different clinical variants. These groups were coordinated by experts leaders and prepared a preliminary document that was discussed in Quito during July 8th and 9th, 2011. Finally the final version was submitted to the members and delegates of LACTRIMS in most of the Latin American countries who were able to make modifications and suggest changes to the final manuscript. CONCLUSIONS. Based on the different evidence levels and the AGREE criteria, the clinical variants were reviewed and recommendations were made for the use of drugs and different modifying disease therapeutic agents.

The epidemiology of multiple sclerosis in Latin America and the Caribbean: a systematic review

The incidence and prevalence of multiple sclerosis (MS) varies geographically as shown through extensive epidemiological studies performed mainly in developed countries. Nonetheless, scant data is available in Latin America and the Caribbean (LAC). The objective of this review is to assess epidemiological data of MS in LAC. We conducted a systematic review of published articles and gray literature from January 1995 to May 2011. Twenty-two studies met the inclusion criteria after full-text review. Incidence data were found in only three studies and ranged from 0.3 to 1.9 annual cases per 100,000 person-years. Prevalence was reported in 10 studies and ranged from 0.83 to 21.5 cases per 100,000 inhabitants. The most prevalent subtype of MS was the relapsing–remitting form (48% to 91% of the series). No data about mortality were found. This study showed low frequency for MS in LAC compared with North American and European countries. The role of environmental and genetic factors should be well studied, providing new insights about its etiology.

Oligoclonal bands in multiple sclerosis patients: worse prognosis?

INTRODUCTION

Cerebrospinal fluid (CSF) oligoclonal bands (OB) imply intrathecal immunoglobulin synthesis and B-cell immune process. There is scarce evidence of OB having a role in disease prognosis. The objective of the present study was to determine OB's prognostic value regarding disease progression.

METHODS

Between January 1994 and January 2007, relapsing-remitting MS (RRMS) patients in which OB were determined were included. Demographic, clinical aspects and presence of OB were analyzed. We compared OB+ versus OB- patients regarding progression to expanded disability status scale (EDSS) of 6·0 and to secondary progressive MS (SPMS). Cox proportional hazard models were used to compare the outcome between groups. P values <0·05 were considered significant.

RESULTS

One hundred and ninety-six patients were included. In 176 patients (90%), the CSF showed type II OB, 20 (10%) patients were OB negative. There were no differences between age, clinical presentation and EDSS at onset or in the immunomodulatory treatment received between OB+ and OB- patients. Sixty-two (31·6%) patients converted to SPMS during the follow-up, 59 (33·5%) were OB+ and 3 (15%) were OB-. EDSS of 6 was recorded in 56 (28·5%) patients during the follow-up; 54 (31%) were OB+ while only 2 (10%) OB- patients reached this outcome (reach SP phase, P = 0·032; HR: 2·2; 95% CI: 1·3-7·5 and EDSS of 6, P = 0·037; HR: 1·9; 95% CI: 1·3-8·5).

CONCLUSION

We observed during the follow-up that OB- patients had a better prognosis and milder disability compared to OB+ patients.

Towards establishing MS prevalence in Latin America and the Caribbean

A very high prevalence of multiple sclerosis (MS) has been reported in some Western European and North American countries. The few surveys of MS epidemiology in South America reveal lower prevalence rates, implying that susceptibility varies between distinct ethnic groups, thus forming an important determinant of the geographic distribution of the disease. The objective of this study is to review MS prevalence estimates in different Latin American and Caribbean countries. We reviewed surveys of regional MS prevalence from 1991 to 2011. Sources included an online database, authors' reports and proceedings or specific lectures from regional conferences. We obtained a total of 30 prevalence surveys from 15 countries, showing low/medium MS prevalence rates. Both the number and the quality of prevalence surveys have greatly improved in this region over recent decades. This is the first collaborative study to map the regional frequency of MS. Establishment of standardized methods and joint epidemiological studies will advance future MS research in Latin America and the Caribbean.

The frequency of CSF oligoclonal banding in multiple sclerosis increases with latitude

BACKGROUND

With the advent of MRI scanning, the value of lumbar puncture to assess oligoclonal band (OCB) status-for the diagnosis of multiple sclerosis (MS) is increasingly uncertain. One major issue is that the reported frequency of cerebrospinal fluid (CSF)-restricted oligoclonal banding for the diagnosis of MS varies considerably in different studies. In addition, the relationship between OCB positivity and disease outcome remains uncertain, as reported studies are generally too small to assess comparative disability outcomes with sufficient power.

METHODS

In order to further investigate variation of OCB positivity in patients with MS, we utilized MSBase, a longitudinal, Web-based collaborative MS outcomes registry following clinical cohorts in several continents and latitudes. We also assessed whether OCB positivity affects long-term disability outcome.

RESULTS

A total of 13,242 patient records were obtained from 37 MS specialist centres in 19 different countries. OCB status was documented in 4481 (34%) patients and 80% of these were OCB positive. The presence of OCB was associated with degree of latitude (p = 0.02). Furthermore, the outcome of patients negative for CSF-specific OCB was significantly better in comparison to the OCB positive patients, as assessed by Expanded Disability Status Scale change (p < 0.001).

CONCLUSIONS

The results of this study indicate that latitude could explain some of the inconsistencies in OCB status reported in different populations. The study confirms that OCB positivity in MS is associated with a worse long-term prognosis.

[Acute transverse myelitis in Buenos Aires, Argentina. A retrospective cohort study of 8 years follow up]

INTRODUCTION

Epidemiological studies on acute transverse myelitis (ATM) in South America are scarce. The aim of our study was to describe demographic, clinical and para-clinical features of patients with ATM in a health care organisation in Buenos Aires. A further objective was to determine the aetiologies of ATM.

METHODS

All patients diagnosed with ATM between June 1, 2002 and June 30, 2010 were retrospectively identified, using the Transverse Myelitis Consortium Working Group criteria.

RESULTS

A total of 40 patients diagnosed with ATM, (24 females, 60%) were included. The mean follow-up was 57 ± 8 months. The principal cause of myelitis found was ATM secondary to demyelinating disease (55%). Idiopathic ATM was diagnosed in 15 (37.5%) cases in the sample. The majority of patients had an extensive cord lesion (50%) detectable with spinal MRI.

CONCLUSION

There are few epidemiological studies concerning ATM in Argentina, and we believe that it is important to be aware of the manner in which this condition manifests itself in this region. We would therefore be able to compare them with studies previously published in other countries.