Detection of interleukin-2 is not useful for distinguishing between latent and active tuberculosis in clinical practice: a prospective cohort study.

OBJECTIVE: Previous reports have identified interleukin-2 (IL-2), quantified in the supernatants of QuantiFERON®-TB Gold In-tube (QFT) after 72 h of incubation, as a potential biomarker for distinguishing between latent and active tuberculosis (TB). However, its validity has not been tested in an appropriate clinical cohort. METHODS: A multicentre study of 161 consecutive adult patients undergoing evaluation for active TB at eight TB Units in Spain. Interferon-γ (IFN-γ) and IL-2 were assessed in the supernatant of QFT after 16-24 h and 72 h of incubation. The accuracy of IL-2 for indicating latent TB infection (LTBI) was assessed by receiving operating characteristic curves. . RESULTS: Twenty-eight participants were not infected, 43 had LTBI, 69 had TB, and 21 were not classifiable. Median (interquartile range) IL-2 concentrations after 72 h of incubation were 0.0 pg/mL (0.0-0.0) in uninfected individuals, 261.0 pg/mL (81.0-853.0) in LTBI individuals, 166.5 pg/mL (33.5-551.5) in patients with extrapulmonary TB, 95.0 pg/mL (26.0-283.0) in patients with smear-negative pulmonary TB, and 38.5 pg/mL (7.5-178.0) in patients with smear-positive pulmonary TB (p <0.0001). The area under the curve of the receiving operating characteristic curve (95% CI) of IL-2 after 72 h of incubation for the diagnosis of LTBI was 0.63 (0.53-0.74) when all TB cases were considered as a single group, ranging from 0.59 (0.47-0.71) to 0.72 (0.58-0.85) when only extrapulmonary and smear-positive pulmonary TB cases respectively were considered. CONCLUSIONS: Quantification of IL-2 in the supernatant of QFT after a prolonged incubation is not useful to distinguish between LTBI and active disease in clinical practice.

[Pyogenic liver abscess: changes in etiology, diagnosis and treatment over 18 years]. / Absceso hepático piógeno: cambios en la etiología, diagnóstico y tratamiento a lo largo de 18 años.

BACKGROUND: There are no detailed studies in our country on the impact of modern imaging techniques on diagnosis, treatment and prognosis of pyogenic liver abscesses. MATERIAL AND METHODS: All patients with the diagnosis of PLA from 1981 to 1998 were included in the study. The study was divided in two periods: 1981 to 1989 and 1990 to 1998. RESULTS: Compared with the first time period, the following was observed from 1990 to 1998: the mean age was higher (52 versus 65 years, p = 0.006), infections with identified source increased (33% versus 74%, p = 0.003), diagnosis was earlier (13 versus 3 days, p = 0.0002), modern imaging techniques were used more frequently (17% versus 96%, p = 0.002), the proportion of recovered microorganisms increased (53% versus 88%, p = 0.002), as well as use of percutaneous drainage (0% versus 37%, p = 0.002) and the prognosis was better (mortality rate 40% versus 10%, p = 0.01). CONCLUSIONS: Relevant changes were observed among patients in our hospital in the nineties regarding epidemiology, management and prognosis of PLAs. Part of these changes are due to a higher use of new imaging techniques.

[Bacteremia in the elderly. Clinical features and prognostic factors]. / Bacteriemia en ancianos. Aspectos clínicos y factores pronósticos.

BACKGROUND: The analysis of the most relevant characteristics and prognostic factors in elderly patients with bacteremia. PATIENTS AND METHODS: For the period 1989-1993 a prospective study of all significant bacteremias in adult patients admitted to a General Hospital was performed. Patients were visited until their death or during at least 50 days. The most relevant findings in elderly patients (over 65 years old) are described. Overall survival probabilities were obtained by Kaplan-Merner analysis. Cox proportional models were used to examine hazards of dying. RESULTS: Of the 1,128 bacteremias studied, 603 (53.9%) were in elderly patients. In this group, the increasing age was related with higher frequency of urinary (p = 0.02) and biliary (p = 0.001) sources of infection and lower frequency of underlying neoplasia (p = 0.06), immunosuppression (p = 0.0000) and development of septic shock (p = 0.02). These differences are higher in patients over 85. Among older patients the survival probability in the day 21 after diagnosis was 0.71 (95% CI 0.66-0.74), significantly lower to the probability in younger patients (p = 0.0001). In the elderly patients, the worse prognestic was associated to shock (RR = 8; 95% CI 5.8-11), indeterminated source of infection (RR = 3.6; 95% CI 2.2-5.8), underlying neoplasia (RR = 1.7; 95% CI 1.3-2.4), neutropania (RR = 1.5; 95% CI 1.1-2.1) nosocomial acquisition (RR = 1.3; 95% CI 1.0-3.1) and inappropriate treatment (RR = 1.2; 95% CI 1.0-3.2), but age was not an independent contributor. CONCLUSIONS: We found differences between the clinical characteristics and the prognosis of bactermia in elderly and younger patients. Among elder patients, those over 85 years old constitute a particular group with well defined characteristics.