Incidence of tuberculosis in HIV-infected patients in Spain: the impact of treatment for LTBI.

SETTING: Twenty hospitals in Spain. OBJECTIVE: To describe the incidence of active tuberculosis (TB) and factors related to TB development after treatment for latent tuberculous infection (TLTBI) in human immunodeficiency virus-1 (HIV-1) infected patients in the highly active antiretroviral therapy era. DESIGN: In a multicentre cohort of HIV-1-infected patients, we calculated TB incidence by tuberculin skin test (TST) results and TLTBI, and factors associated with a positive TST and the development of TB after TLTBI. RESULTS: Of 7902 patients, 6.5% had a history of TB at enrolment: 168 patients developed TB during 10,889 person-years (py) of follow-up, corresponding to an incidence rate of 1.54 cases per 100 py (95%CI 1.33-1.80). TB incidence in TST-positive patients who did not receive TLTBI was three times higher (6 cases/100 py) than in those who did (1.75 cases/100 py). In patients who received TLTBI, risk of development of TB was higher among cases aged <35 years (HR 6.14, 95%CI 1.12-33.73) and in those with a nadir CD4(+) cell count of <200 cells/µl (HR 5.64, 95%CI 1.34-23.70). CONCLUSIONS: TLTBI is effective in preventing the development of TB in HIV-infected patients, particularly in those who were TST-positive.

Do thyroid cancer patients with basal undetectable Tg measured by current immunoassays require rhTSH testing?

OBJECTIVE: To evaluate the predictive value of disease free status of basal thyroglobulin (Tg) in differentiated thyroid carcinoma (DTC). DESIGN: Basal and recombinant human TSH (rhTSH) stimulated Tg measured with a commercial immunoassay (Liaison DiaSorin, Italial), neck ultrasonography (US) and fine needle aspiration cytology if required were performed in DTC patients followed prospectively for 6.8 years in a university hospital. 92 consecutive DTC patients were included. 74 patients with basal and stimulated Tg <1.0 ng/ml and Tg antibodies and US negative were considered as disease-free and persistent/recurrent disease was detected in 18 patients. In 25/74 disease-free patients rhTSH test was repeated within one year. RESULTS: 63/92 patients had undetectable basal Tg (<0.5 ng/ml), with rhTSH-Tg <0.5 ng/ml in 52, in 6 rhTSH-Tg between 0.5 and 1 ng/ml, in 2 between 1-2 ng/ml (disease-free after 3 years of follow-up) and >2.0 ng/ml (mean 4.1±2.4 ng/ml) in another 3, with US lymphatic metastasis confirmed histologically. Disease-free state was predicted with a sensitivity (S) of 66.7% and specificity (Sp) of 75.7% for basal Tg-0.5 ng/ml, and S 100% and Sp 85.1% for stimulated Tg-0.92. rhTSH test and US were repeated within one year in 25 disease-free patients with Tg<1.0 ng/ml. No further elevation below 1 ng/ml was observed. CONCLUSIONS: Low risk patients with undetectable basal Tg measured with current commercially available immunoassays should be followed with at least one rhTSH stimulated Tg and neck US because of the insufficient predictive value for recurrence/persistent disease of basal Tg.