Endocrine abnormalities in HIV-infected women are associated with peak viral load - the Children and Women: AntiRetrovirals and Markers of Aging (CARMA) Cohort.

OBJECTIVES: To investigate the prevalence of endocrine disturbances in a group of HIV-positive (HIV+) women and to identify factors affecting presence of these disorders. To examine specifically whether cellular ageing, as measured by leukocyte telomere length (LTL), is correlated with the presence of endocrine disturbance. DESIGN: A cross-sectional retrospective substudy of an ongoing prospective cohort study. PATIENTS: Adult HIV+ (≥19 years) women enrolled in the CARMA (Children and Women: AntiRetrovirals and Markers of Aging) cohort study (N = 192). Prevalences of T2DM, glucose intolerance, dyslipidaemia, thyroid disorders, adrenal insufficiency, hypogonadism, primary ovarian insufficiency (POI), demographics, HIV and hepatitis C virus (HCV) infection status, baseline LTL, combined antiRetroviral therapy (cART) and substance exposures were collected. Statistical analysis included univariable followed by multivariable Poisson regression and step-wise reduction to refine the multivariable model. RESULTS: Prevalence of any endocrine abnormality was 58% (dyslipidaemia 43%, glucose intolerance/T2DM 13%, thyroid disorders 15%). In multivariable analysis, age was associated with number and type (any, glucose, lipid) of abnormality, while increasing body mass index (BMI) was associated with number of diagnoses and with glucose metabolism disorders. Interestingly, peak HIV pVL ≥100 000 copies/ml was associated with any abnormality, total number of disorders and presence of a thyroid disorder, while any disorder, glucose abnormalities and dyslipidaemia were negatively associated with alcohol use. LTL was not associated with number or type of endocrine abnormalities in this study. CONCLUSION: Further studies examining the relationship between duration and extent of exposure to HIV viraemia in relation to developing abnormal endocrine function are warranted.

Regulation of B cell linker protein transcription by PU.1 and Spi-B in murine B cell acute lymphoblastic leukemia.

B cell acute lymphoblastic leukemia (B-ALL) is frequently associated with mutations or chromosomal translocations of genes encoding transcription factors. Conditional deletion of genes encoding the E26-transformation-specific transcription factors, PU.1 and Spi-B, in B cells (ΔPB mice) leads to B-ALL in mice at 100% incidence rate and with a median survival of 21 wk. We hypothesized that PU.1 and Spi-B may redundantly activate transcription of genes encoding tumor suppressors in the B cell lineage. Characterization of aging ΔPB mice showed that leukemia cells expressing IL-7R were found in enlarged thymuses. IL-7R-expressing B-ALL cells grew in culture in response to IL-7 and could be maintained as cell lines. Cultured ΔPB cells expressed reduced levels of B cell linker protein (BLNK), a known tumor suppressor gene, compared with controls. The Blnk promoter contained a predicted PU.1 and/or Spi-B binding site that was required for promoter activity and occupied by PU.1 and/or Spi-B as determined by chromatin immunoprecipitation. Restoration of BLNK expression in cultured ΔPB cells opposed IL-7-dependent proliferation and induced early apoptosis. We conclude that the tumor suppressor BLNK is a target of transcriptional activation by PU.1 and Spi-B in the B cell lineage.

Deletion of genes encoding PU.1 and Spi-B in B cells impairs differentiation and induces pre-B cell acute lymphoblastic leukemia.

The E26 transformation-specific (Ets) transcription factor PU.1 is required to generate lymphoid progenitor cells from hematopoietic stem cells, but it is not required to generate B cells from committed B-cell lineage progenitors. We hypothesized that PU.1 function in B-cell differentiation is complemented by the related Ets transcription factor Spi-B. To test this hypothesis, mice were generated lacking both PU.1 and Spi-B in the B-cell lineage. Unlike mice lacking PU.1 or Spi-B, mice deficient in both PU.1 and Spi-B in the B-cell lineage had reduced frequencies of B cells as well as impaired B-cell differentiation. Strikingly, all PU.1 and Spi-B-deficient mice developed pre-B cell acute lymphoblastic leukemia before 30 weeks of age. Pre-B cells accumulated in the thymus resulting in massive thymic enlargement and dyspnea. These findings demonstrate that PU.1 and Spi-B are essential transcriptional regulators of B-cell differentiation as well as novel tumor suppressors in the B-cell lineage.