Publications

Turner Syndrome patients have an absent second sex chromosome and a predisposition to autoimmune disease. We hypothesized that the autoimmune susceptibility in Turner Syndrome may be due to an alteration in the expression of the X-linked FOXP3 gene. FOXP3 is important in the development of regulatory T cells, and complete loss of FOXP3 expression has been shown to result in severe autoimmunity. To test this hypothesis, we characterized the regulatory T cells and performed immunophenotyping on the peripheral blood leukocytes of a cohort of Turner Syndrome patients. These patients retained regulatory T cell frequency and function despite an increased prevalence of autoimmunity. Immunophenotyping revealed a decrease in the ratio of CD4 to CD8 lymphocytes. These findings suggest that the autoimmune predisposition in Turner Syndrome is not due to alterations in regulatory T cells but may be associated with a change in the proportion of T cell subsets.

Activation of latent transforming growth factor beta (TGF-beta) by alphavbeta6 integrin is critical in the pathogenesis of lung injury and fibrosis. We have previously demonstrated that the stimulation of protease activated receptor 1 promotes alphavbeta6 integrin-mediated TGF-beta activation via RhoA, which is known to modulate cell contraction. However, whether other G protein-coupled receptors can also induce alphavbeta6 integrin-mediated TGF-beta activation is unknown; in addition, the alphavbeta6 integrin signaling pathway has not yet been fully characterized. In this study, we show that lysophosphatidic acid (LPA) induces alphavbeta6-mediated TGF-beta activation in human epithelial cells via both RhoA and Rho kinase. Furthermore, we demonstrate that LPA-induced alphavbeta6 integrin-mediated TGF-beta activity is mediated via the LPA2 receptor, which signals via G alpha(q). Finally, we show that the expression levels of both the LPA2 receptor and alphavbeta6 integrin are up-regulated and are spatially and temporally associated following bleomycin-induced lung injury. Furthermore, both the LPA2 receptor and alphavbeta6 integrin are up-regulated in the overlying epithelial areas of fibrosis in patients with usual interstitial pneumonia. These studies demonstrate that LPA induces alphavbeta6 integrin-mediated TGF-beta activation in epithelial cells via LPA2, G alpha(q), RhoA, and Rho kinase, and that this pathway might be clinically relevant to the development of lung injury and fibrosis.

BACKGROUND

Risk factors and treatment outcomes under program conditions for isoniazid (INH)-monoresistant tuberculosis have not been well described.

METHODS

Medical charts were retrospectively reviewed for all cases of culture-confirmed, INH-monoresistant tuberculosis ( n = 137) reported to the San Francisco Department of Public Health Tuberculosis Control Section from October 1992 through October 2005, and those cases were compared with a time-matched sample of drug-susceptible tuberculosis cases (n = 274)

RESULTS

In multivariate analysis, only a history of treatment for latent tuberculosis (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.5-6.4; P = .003) or for active tuberculosis (OR, 2.7; 95% CI, 1.4-5.0; P = .002) were significantly associated with INH-monoresistant tuberculosis. Of the 119 patients who completed treatment, 49 (41%) completed a 6-month treatment regimen. Treatment was extended to 7-12 months for 53 (45%) of the patients and to >12 months for 17 (14%). Treatment was most commonly extended because pyrazinamide was not given for the recommended 6-month duration (35 patients [29%]). Despite variation in treatment regimens, the combined end point of treatment failure or relapse was uncommon among patients with INH-monoresistant tuberculosis and was not significantly different for patients with drug-susceptible tuberculosis (1.7% vs. 2.2%; P = .73).

CONCLUSIONS

A history of treatment for latent or active tuberculosis was associated with subsequent INH monoresistance. Treatment outcomes for patients with INH-monoresistant tuberculosis were excellent and were no different from those for patients with drug-susceptible tuberculosis. However, new, short-course regimens are needed because a small proportion of patients completed the 6-month treatment regimen recommended by the American Thoracic Society, Centers for Disease Control and Prevention, and Infectious Diseases Society of America, primarily because of pyrazinamide intolerance.

OBJECTIVE

To compare differences in long-term outcome between adults with childhood-onset (age at diagnosis <18 years) systemic lupus erythematosus (SLE) and with adult-onset SLE.

METHODS

Data were derived from the University of California Lupus Outcomes Study, a longitudinal cohort of 885 adult subjects with SLE (90 childhood-onset [cSLE], 795 adult-onset [aSLE]). Baseline and 1-year followup data were obtained via structured 1-hour telephone interviews conducted between 2002 and 2006. Using self-report data, differences in organ involvement and disease morbidity, current disease status and activity, past and current medication use, and number of physician visits were compared, based on age at diagnosis of SLE.

RESULTS

Average disease duration for the cSLE and aSLE subgroups was 16.5 and 13.4 years, respectively, and mean age at followup was 30.5 and 49.9 years, respectively. When compared with aSLE subjects, cSLE subjects had a higher frequency of SLE-related renal disease, whereas aSLE subjects were more likely to report a history of pulmonary disease. Rates of clotting disorders, seizures, and myocardial infarction were similar between the 2 groups. At followup, cSLE subjects had lower overall disease activity, but were more likely to be taking steroids and other immunosuppressive therapies. The total number of yearly physician visits was similar between the 2 groups, although cSLE subjects had a higher number of nephrology visits.

CONCLUSION

This study demonstrates important differences in the outcomes of patients with cSLE and aSLE, and provides important prognostic information about long-term SLE disease activity and treatment.