HIV matters when diagnosing TB in young children: an ancillary analysis in children enrolled in the INPUT stepped wedge cluster randomized study.

BACKGROUND: Children under age five years, particularly those living with HIV (CLHIV), are at risk for rapid progression of tuberculosis (TB). We aimed to describe TB clinical presentations, diagnostic pathways and treatment outcomes in CLHIV compared to children without HIV in Cameroon and Kenya. METHODS: This sub-analysis of a cluster-randomized trial evaluating the integration of pediatric TB services from May 2019 to March 2021 enrolled children age < 5 years with TB. We estimated the HIV infection rate with 95% confidence interval (CI). We compared TB clinical presentations, diagnostic pathways and treatment outcomes in CLHIV and children without HIV. Finally, we investigated whether HIV infection was associated with a shorter time to TB diagnosis (≤ 3 months from symptoms onset) after adjusting for covariates. Univariable and multivariable logistic regression analysis were performed with adjusted odds ratios (AORs) presented as measures of the association of covariates with HIV status and with shorter time to TB diagnosis. RESULTS: We enrolled 157 children with TB (mean age was 1.5 years) and 22/157 (14.0% [9.0-20.4%]) were co-infected with HIV. CLHIV were more likely to initially present with acute malnutrition (AOR 3.16 [1.14-8.71], p = 0.027). Most TB diagnoses (140/157, 89%) were made clinically with pulmonary TB being the most common presentation; however, there was weak evidence of more frequent bacteriologic confirmation of TB in CLHIV, 18% vs. 9% (p = 0.067), due to the contribution of lateral-flow urine lipoarabinomannan to the diagnosis. HIV positivity (AOR: 6.10 [1.32-28.17], p = 0.021) was independently associated with a shorter time to TB diagnosis as well as fatigue (AOR: 6.58 [2.28-18.96], p = 0.0005), and existence of a household contact diagnosed with TB (AOR: 5.60 [1.58-19.83], p = 0.0075), whereas older age (AOR: 0.35 [0.15-0.85], p = 0.020 for age 2-5 years), night sweats (AOR: 0.24 [0.10-0.60], p = 0.0022) and acute malnutrition (AOR: 0.36 [0.14-0.92], p = 0.034) were associated with a delayed diagnosis. The case fatality rate was 9% (2/22) in CLHIV and 4% (6/135) in children without HIV, p = 0.31. CONCLUSIONS: These results altogether advocate for better integration of TB services into all pediatric entry points with a special focus on nutrition services, and illustrate the importance of non-sputum-based TB diagnostics especially in CLHIV. TRIAL REGISTRATION: NCT03862261, first registration 05/03/2019.

[Buruli ulcers: an advocacy agenda to improve its control]. / Ulcère de Buruli : construction d'un agenda de plaidoyer pour améliorer la lutte.

Doctors Without Borders (Médecins Sans Frontières) has developed an advocacy agenda in Cameroon to better meet its patients' needs and to simplify control of Buruli ulcers. This agenda is based on 4 priorities: diagnostic (development of a clinical score), chemotherapeutic (to envision drug administration at home, without daily hospital visits), dressings, and HIV coinfection. These priority objectives should make it possible to reduce the duration of hospitalization and limit the need for surgery.

p53 displacement from centrosomes and p53-mediated G1 arrest following transient inhibition of the mitotic spindle.

Growing evidence indicates a central role for p53 in mediating cell cycle arrest in response to mitotic spindle defects so as to prevent rereplication in cells in which the mitotic division has failed. Here we report that a transient inhibition of spindle assembly induced by nocodazole, a tubulin-depolymerizing drug, triggers a stable activation of p53, which can transduce a cell cycle inhibitory signal even when the spindle-damaging agent is removed and the spindle is allowed to reassemble. Cells transiently exposed to nocodazole continue to express high levels of p53 and p21 in the cell cycle that follows the transient exposure to nocodazole and become arrested in G(1), regardless of whether they carry a diploid or polyploid genome after mitotic exit. We also show that p53 normally associates with centrosomes in mitotic cells, whereas nocodazole disrupts this association. Together these results suggest that the induction of spindle damage, albeit transient, interferes with the subcellular localization of p53 at specific mitotic locations, which in turn dictates cell cycle arrest in the offspring of such defective mitoses.

Regulated Ran-binding protein 1 activity is required for organization and function of the mitotic spindle in mammalian cells in vivo.

Ran-binding protein (RanBP) 1 is a major regulator of the Ran GTPase and is encoded by a regulatory target gene of E2F factors. The Ran GTPase network controls several cellular processes, including nucleocytoplasmic transport and cell cycle progression, and has recently also been shown to regulate microtubule nucleation and spindle assembly in Xenopus oocyte extracts. Here we report that RanBP1 protein levels are cell cycle regulated in mammalian cells, increase from S phase to M phase, peak in metaphase, and abruptly decline in late telophase. Overexpression of RanBP1 throughout the cell cycle yields abnormal mitoses characterized by severe defects in spindle polarization. In addition, microinjection of anti-RanBP1 antibody in mitotic cells induces mitotic delay and abnormal nuclear division, reflecting an abnormal stabilization of the mitotic spindle. Thus, regulated RanBP1 activity is required for proper execution of mitosis in somatic cells.

p53-independent apoptosis and p53-dependent block of DNA rereplication following mitotic spindle inhibition in human cells.

We have studied the response of human transformed cells to mitotic spindle inhibition. Two paired cell lines, K562 and its parvovirus-resistant KS derivative clone, respectively nonexpressing and expressing p53, were continuously exposed to nocodazole. Apoptotic cells were observed in both lines, indicating that mitotic spindle impairment induced p53-independent apoptosis. After a transient mitotic delay, both cell lines exited mitosis, as revealed by flow-cytometric determination of MPM2 antigen and cyclin B1 expression, coupled to cytogenetic analysis of sister centromere separation. Both cell lines exited mitosis without chromatid segregation. K562 p53-deficient cells further resumed DNA synthesis, giving rise to cells with a DNA content above 4C, and reentered a polyploid cycle. In contrast, KS cells underwent a subsequent G1 arrest in the tetraploid state. Thus, G1 arrest in tetraploid cells requires p53 function in the rereplication checkpoint which prevents the G1/S transition following aberrant mitosis; in contrast, p53 expression is dispensable for triggering the apoptotic response in the absence of mitotic spindle.