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Abstract: Objective: To identify HLA-DRB1 alleles contributing to susceptibility to multiple sclerosis (MS) in a Colombian population and to estimate the common effect size of HLA class II on MS susceptibility in Latin American populations through a meta-analysis. Methods: A total of 65 Colombian patients with MS and 184 matched controls were included. HLA-DRB1 typing was done using the sequence-specific oligonucleotide probe method. A bivariate and a multivariate logistic regression analyses were done. Case-control studies performed in Latin America were searched up to January 2009 through a systematic review of the literature. Effect summary odds ratios (ORs) and 95% confidence intervals (CIs) were obtained by means of the random effect model. Results: A total of 464 cases and 2581 controls from 7 studies and the results of the present study in Colombians were analyzed. HLA-DRB1⁎15 (OR: 2.3; 95% CI: 1.68–3.07; p <0.001) and HLA-DQB1⁎06 (OR: 2.2; 95% CI: 1.54–3.07; p <0.001) groups as well as DRB1⁎1501 (OR: 2.6; 95% CI: 1.67–4.02; p <0.001), DRB1⁎1503 (OR: 2.2; 95% CI: 1.39–3.62; p =0.001) and DQB1⁎0602 (OR: 2.5; 95% CI: 1.66–3.71; p <0.001) alleles were found to be risk factors for MS. The myelin basic protein immunodominant sequence 221VHFFKNIVT229 was predicted to strongly and simultaneously bind to HLA-DRB1⁎1501 and ⁎1503. Conclusion: The current study highlights the effect size of HLA class II in MS in Latin America and confirms similar allelic risk factors across diverse populations. Receptor-ligand interactions in the HLA-antigenic peptide complex could have potential predictive and therapeutical implications. [Copyright &y& Elsevier]

Rationale: Nocardia species are not commonly referred as primary infectious entities but rather as opportunistic pathogens. Infectious cases of Nocardia spp. in immunocompetent individuals are rare., Patient Concerns: An immunocompetent 58-year-old patient presented with recurrent headaches., Diagnosis: A brain abscess was found and surgically drained. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and heat shock protein 65/16S-23S rRNA gene intergenic spacer genotyping from the sample revealed the etiological agent as Nocardia beijingensis., Interventions: Meropenem/amikacin/Trimethoprim-sulfamethoxazole were administered., Outcomes: The infection persisted leading to the patient's death., Lessons: Here we present the first case of N. beijingensis infection of the central nervous system in an immunocompetent patient from Latin America. Further inquiry is needed to establish whether this species is more virulent than other Nocardia isolates.