Diabetes mellitus is associated with an increased risk of unsuccessful treatment outcomes among drug-susceptible tuberculosis patients in Ethiopia: A prospective health facility-based study.

Background: The impact of diabetes mellitus on tuberculosis (TB) treatment outcomes has not been well investigated in most sub-Saharan countries including Ethiopia. The current study aimed to determine the association between diabetes mellitus and unsuccessful TB treatment outcomes among drug-susceptible TB patients treated at selected health facilities in Addis Ababa, Ethiopia. Methods: This health facility-based prospective cohort study was conducted at six randomly selected public health centers in Addis Ababa, from August 2020 until November 2021. Clinically diagnosed adult pulmonary and extra pulmonary TB patients were recruited at the time of treatment initiation. A multivariable logistic regression analysis was used to estimate the association between diabetes and unsuccessful TB treatment outcomes. Results: Among the total 267 enrolled participants, 9.7% of patients with TB were identified to have diabetes comorbidity. Of patients with diabetes and TB, 9 (34.6%) were newly diagnosed based on glucose test results. Despite an overall high TB treatment success rate (94.0%), more than one-fourth (26.9%) of patients with diabetes had a poor TB treatment outcome (26.9%), which was remarkably higher compared to patients without diabetes (3.7%). In multivariable regression, the adjusted odds of poor TB treatment outcome among those with diabetes was 14.8 (95% CI 3.5 - 62.7) times the odds of poor outcome patients without diabetes. Conclusion: Diabetes was significantly associated with increased odds of poor TB treatment outcomes among patients in Addis Ababa, Ethiopia.

Identification of Th0 cells responding to measles virus.

Mechanisms involved in the induction of immunity to measles virus (MV) are not well understood. In the present study, we assessed proliferation, interferon (IFN)-gamma, and interleukin (IL)-4 production of MV-specific T cells after secondary in vitro stimulation of peripheral blood mononuclear cells (PBMCs) from human donors. Such secondary stimulation resulted in responses substantially higher than after primary in vitro exposure. Most study participants produced both IFN-gamma and IL-4 after secondary in vitro stimulation. Patterns of secondary in vitro responses that use genetically disparate antigen-presenting cells were consistent with T-cell recognition restricted to human leukocyte antigen class II molecules. Limiting dilution analyses indicated that precursor frequencies of cytokine secreting and proliferating cells ranged from about 0.001% to 0.1% among fresh PBMCs. Split-well analyses of limiting dilution cultures suggested that virtually all putative T-cell clones produced either IFN-gamma alone or both IFN-gamma and IL-4. Intracytoplasmic flow cytometric analysis of polyclonal MV-specific secondary in vitro responding T cells revealed a similar pattern of cytokine expression. These results suggest that memory T cells responding in vitro to MV generate cells that produce either IFN-gamma alone (and resemble Th1-like cells) or secreted both IFN-gamma and IL-4 (resembling Th0-like cells) in vitro with few cells expressing a Th2-like pattern.

Interleukin-4 induced by measles virus and measles-derived peptides as measured by IL-4 receptor-blocking ELISA.

Interleukin-4 (IL-4) is a signature cytokine for T-helper 2 (Th2) type immune responses in humans. However, data on antigen-specific secretion of IL-4 is limited due to difficulties detecting IL-4. We evaluated an IL-4 receptor-blocking assay for the detection of secreted IL-4 in peripheral blood mononuclear cells (PBMC) stimulated in vitro with measles virus (MV) and MV-derived nucleoprotein (N) and phosphoprotein (P) peptides. We recruited 20 healthy subjects, previously immunized with two doses of measles-mumps-rubella-II (MMR-II) vaccine. We evaluated the cellular and humoral immune status of these study subjects by an in vitro lymphoproliferation assay and an enzyme-linked immunosorbent assay (ELISA), respectively. We analyzed the MV-induced and N and P peptide-induced IL-4 levels in PBMC culture supernatants. Using the IL-4 receptor blocking assay, 50% of the subjects were positive for secreted IL-4 in response to MV stimulation, and 5% and 23.1% of study subjects were positive for secreted IL-4 in response to MV-derived N and P peptides, respectively. In contrast, we did not find any positive secreted IL-4 response to MV using conventional ELISA without IL-4 receptor-blocking antibody in our optimization study. Further, we found very low frequencies of IL-4 secreting cells using an alternate ELISpot technique, accounting for only a 5% positive response to MV and no response to P peptide. We propose that the IL-4 receptor-blocking assay is an easy-to-adapt technique for screening antigen-specific immune responses in large-scale population-based studies.