HIV testing in US tuberculosis care settings: a survey of current practice and perceived barriers.

CONTEXT: Extent of and challenges to implementation of the Centers for Disease Control and Prevention (CDC) 2006 recommendation for routine HIV testing have not been reviewed specifically within tuberculosis (TB) care settings. OBJECTIVE: To determine current adherence to the CDC's HIV testing recommendations in TB care settings and identify barriers. DESIGN: An online survey was designed and distributed via Survey Monkey. SETTING: The 2011 National TB Conference attendees, National TB Nurse Controllers, and the CDC's TB-educate mailing list were invited to participate via e-mail. PARTICIPANTS: A total of 153 respondents from US states: 30 physicians, 91 nurses, 19 public health practitioners, and 13 other. MAIN OUTCOME MEASURES: Perceived importance of HIV testing, current HIV testing practices, perceived barriers to HIV testing, and understanding of state HIV testing laws. RESULTS: One hundred forty-one of 153 (92.2%) reported that patients with TB disease were "always" or "almost always" HIV tested; 65 of 153 (42.5%) reported the same for patients with latent TB infection (LTBI). Among those not routinely testing LTBI patients, "patient refusal of test" (53/88; 60.2%), "cost" (41/88; 46.6%), and "prevalence too low to justify" (33/88; 37.5%) were the most commonly identified barriers to opt-out testing. Forty-seven of 59 providers (79.7%) who reported that their state required written consent for HIV testing had incorrect knowledge regarding HIV testing legislation. CONCLUSIONS: Rates of HIV testing are high for patients with TB disease, but fewer than half of providers' care settings routinely test LTBI patients. Knowledge of HIV status is required to appropriately interpret TST results and make decisions regarding treatment in TB infection, since HIV coinfection increases risk of progression to active TB. Lack of HIV testing in LTBI patients represents a missed opportunity to prevent TB disease and its resultant morbidity and mortality. In addition, incorrect knowledge regarding testing legislation was a common problem among our TB providers. Further work is necessary to improve HIV testing rates in patients who have not yet progressed to active TB disease.

Proline-rich region of non-muscle myosin light chain kinase modulates kinase activity and endothelial cytoskeletal dynamics.

Disruption of the pulmonary endothelial barrier and subsequent vascular leak is a hallmark of acute lung injury. Dynamic rearrangements in the endothelial cell (EC) peripheral membrane and underlying cytoskeleton are critical determinants of barrier function. The cytoskeletal effector protein non-muscle myosin light chain kinase (nmMLCK) and the actin-binding regulatory protein cortactin are important regulators of the endothelial barrier. In the present study we functionally characterize a proline-rich region of nmMLCK previously identified as the possible site of interaction between nmMLCK and cortactin. A mutant nmMLCK construct deficient in proline residues at the putative sites of cortactin binding (amino acids 973, 976, 1019, 1022) was generated. Co-immunoprecipitation studies in human lung EC transfected with wild-type or mutant nmMLCK demonstrated similar levels of cortactin interaction at baseline and after stimulation with the barrier-enhancing agonist, sphingosine 1-phosphate (S1P). In contrast, binding studies utilizing recombinant nmMLCK fragments containing the wild-type or proline-deficient sequence demonstrated a two-fold increase in cortactin binding (p<0.01) to the mutant construct. Immunofluorescent microscopy revealed an increased stress fiber density in ECs expressing GFP-labeled mutant nmMLCK at baseline (p=0.02) and after thrombin (p=0.01) or S1P (p=0.02) when compared to wild-type. Mutant nmMLCK demonstrated an increase in kinase activity in response to thrombin (p<0.01). Kymographic analysis demonstrated an increased EC membrane retraction distance and velocity (p<0.01) in response to the barrier disrupting agent thrombin in cells expressing the mutant vs. the wild-type nmMLCK construct. These results provide evidence that critical prolines within nmMLCK (amino acids 973, 976, 1019, 1022) regulate cytoskeletal and membrane events associated with pulmonary endothelial barrier function.