Diagnostic performance and impact of routinely implemented Xpert® MTB/RIF assay in a setting of high incidence of drug-resistant TB in Odessa Oblast, Ukraine.

OBJECTIVES AND METHODS: The Xpert® MTB/RIF assay (Cepheid, Sunnyvale, CA, USA) has been in routine use in Odessa Oblast, a region with the highest tuberculosis (TB) incidence in Ukraine, since 2013. We assessed the performance of the assay in routine settings and evaluated its effect on treatment outcomes. RESULTS: The sensitivity of Xpert for TB detection was 93.7% (1165/1243) and 69.5% (448/645) for smear-positive and smear-negative sputum specimens, respectively, and its sensitivity for rifampicin resistance was 93.4% (1212/1298). Median time to TB detection using the Xpert assay was 0 days. Treatment initiation within 1 week increased the proportion of successful outcomes (60.1% versus 25.9%, RR = 1.86, 95%CI = 1.46-2.42), but the introduction of Xpert MTB/RIF has not led to a significant improvement in treatment outcomes (57.2% versus 46.2%; RR = 0.93, 95%CI = 0.77-1.12). CONCLUSION: Performance characteristics of the Xpert assay demonstrated during its routine implementation in an area of high TB and drug-resistant TB incidence in Ukraine were in line with those demonstrated in similar settings elsewhere. Rollout of rapid molecular testing may lead to better treatment results provided that it is implemented in conjunction with other programmatic improvements.

IMMUNOPHENOTYPICAL CHARACTERISTICS OF CELLULAR COMPOSITION IN BREAST MILK.

The morphology and immunophenotype of female colostrum adherent cells with the help of CD3, CD31, CD34, CD45, CD68, vimentin, and osteocalcin antibodies panel was studied in short-term (6­7 days) culture in vitro. Approximately equal (1 : 1) ratio of fibroblast-like and rounded cells was observed in 20 % of cultural flasks. The cells with regular shape mixed with single fibroblasts were noted in 80 % of cultural flasks. The diameter of spreaded cells varied within 10­100 mm. All cells adhered to plastics did not express CD3 and interacted slightly (sl) with antibodies to CD31, CD34, and CD45. At the same time, adherent cells with intensive CD68, vimentin and osteocalcin staining have been revealed. Literature data allows to interpret CD68+CD3­CD31slCD34slCD45sl immunophenotype of significant part of mother colostrum adherent cells as belonging to monocyte-macrophage lineage. Marked expression of stromal antigens (vimentin, osteocalcin) in 40­45 % adherent cells in cultural medium without osteogenic supplements (beta-glycerophosphate, ascorbic acid, dexamethasone) proposes an existence of osteoblasts fraction differentiated in colostrum from mesenchymal stem cells under an action of breast milk humoral factors.