Lymphoproliferative disorders in non-AIDS associated Kaposi's sarcoma

The association of the non-AIDS-related, classic fonn of Kaposi's sarcoma (KS) with secondary malignancies, especially Iymphoproliferative disorders, has frequently been noted. However, in endemic: African-type KS, such an association has been reported only rarely. A review of 62 non-AIDS-related cases of KS treated and followed up at Johannesburg General Hospital between 1980 and 1992 revealed 8 patients (13%)'in whom KS was associated with malignant Iymphoproliferative disorders. The prevalence of secondary Iymphoproliferative disorders was not significantly different among patients with classic KS (3/15; 20%) when compared with those who had African KS (4/47; 8%). In both forms of KS subtle disturbances of immunity have been described which may play a role in the pathogenesis of secondary Iymphoproliferative disorders, although the factors responsible and the pathogenetic mechanisms involved in malignant lymphoid transfonnation in these patients have not been fully elucidated

False-positive rifampicin resistance on Xpert® MTB/RIF: case report and clinical implications [Technical note]

The World Health Organization had endorsed Xpert® MTB/RIF (Xpert) as the initial diagnostic for multidrug-resistant tuberculosis (TB) or TB suspects co-infected with the human immunodeficiency virus. We investigated an unexpected case of rifampicin (RMP) resistance on Xpert using repeat Xpert, smear microscopy, MTBDRplus assay, culture, drug susceptibility testing, spoligotyping and rpoB gene sequencing. A false-positive result was most likely, given the wild type rpoB gene sequence and exclusion of both mixed infection and mixture of drug-susceptible and drug-resistant populations. When decentralising Xpert, test performance characteristics need to be understood by health care workers and methods of confirmation of RMP resistance need to be accessible