PDE6B and tuberculosis: Thus, objectives of this pilot study in HIV-infected individuals from a tropical setting were: i) to evaluate whether this selected RD1 peptide assay may help in providing evidence of diagnosis of active TB in an endemic country; ii) to evaluate changes in the response to RD1 peptides during therapy; iii) to use the approach suggested by Rangaka et al. [24], as an additional tool for the identification of active TB; iv) to compare the results obtained with RD1 peptide assay with the response to RD1 intact proteins, an other in-house RD1 assay largely used in the literature [23-26].