Partial Regulatory T Cell Depletion Prior to Acute Feline Immunodeficiency Virus Infection Does Not Alter Disease Pathogenesis

Feline immunodeficiency virus (FIV) infection in cats follows a disease course similar to HIV-1, including a short acute phase characterized by high viremia, and a prolonged asymptomatic phase characterized by low viremia and generalized immune dysfunction. CD4+CD25hiFoxP3+ immunosuppressive regulatory T (Treg) cells have been implicated as a possible cause of immune dysfunction during FIV and HIV-1 infection, as they are capable of modulating virus-specific and inflammatory immune responses. Additionally, the immunosuppressive capacity of feline Treg cells has been shown to be increased during FIV infection. We have previously shown that transient in vivo Treg cell depletion during asymptomatic FIV infection reveals FIV-specific immune responses suppressed by Treg cells. In this study, we sought to determine the immunological influence of Treg cells during acute FIV infection. We asked whether Treg cell depletion prior to infection with the highly pathogenic molecular clone FIV-C36 in cats could alter FIV pathogenesis. We report here that partial Treg cell depletion prior to FIV infection does not significantly change provirus, viremia, or CD4+ T cell levels in blood and lymphoid tissues during the acute phase of disease. The effects of anti-CD25 mAb treatment are truncated in cats acutely infected with FIV-C36 as compared to chronically infected cats or FIV-naïve cats, as Treg cell levels were heightened in all treatment groups included in the study within two weeks post-FIV infection. Our findings suggest that the influence of Treg cell suppression during FIV pathogenesis is most prominent after Treg cells are activated in the environment of established FIV infection

Prevalence of Musculoskeletal Pain and Statin Use

BACKGROUND: Muscle effects are the most common reported adverse effects of 3-hydroxy-3-methylglutaryl coenzyme A inhibitors (statins). However, in placebocontrolled trials the incidence of muscle pain is most often similar for placebo and active control groups. OBJECTIVE: We sought to evaluate whether statin use was associated with a higher prevalence of musculoskeletal pain in a nationally representative sample. METHODS: Cross-sectional analysis using data from the National Health and Nutrition Examination Survey (NHANES) 1999–2002. Participants were 3,580 adults ≥40 years without arthritis who were interviewed at home and examined in a mobile examination center. Participants were asked about sociodemographic characteristics, health conditions, medication use, and musculoskeletal pain. Height, weight, blood pressure, ankle brachial index, and cholesterol were measured. MEASUREMENTS AND MAIN RESULTS: Prevalence and adjusted odds ratios (OR) of any musculoskeletal pain and musculoskeletal pain in 4 different anatomical regions (neck/upper back, upper extremities, lower back, and lower extremities) by statin use during the last 30 days. Among statin users (n=402), 22.0% (95% CI 18.0–26.7%) reported musculoskeletal pain in at least 1 anatomical region during the last 30 days, compared with 16.7% (95%CI 15.1–18.4%) of those who did not use a statin. Compared to persons who did not use statins, those who used statins had multivariable-adjusted odds ratios (95%CI; p value) of 1.50 (1.07–2.11; p=.01) for any musculoskeletal pain, 1.59 (1.04–2.44, p=.03) for lower back pain, and 1.50 (1.02–2.22, p=.03) for lower extremity pain. CONCLUSION: Musculoskeletal pain is common in adults ≥40 years without arthritis. In this nationally representative sample, statin users were significantly more likely to report musculoskeletal pain