Anales de la Facultad de Ciencias Médicas (Asunción)
Print version ISSN 1816-8949
PICAGUA ARAUJO, E and INSTITUTO DE INVESTIGACIONES EN CIENCIAS DE LA SALUD - UNA et al. Seric level of Beta 2-microglobulin in patients with active pulmonary tuberculosis. An. Fac. Cienc. Méd. (Asunción) [online]. 2009, vol.42, n.2, pp. 31-36. ISSN 1816-8949.
ABSTRACT Introduction: Pulmonary tuberculosis is a chronic inflammatory disease and it is endemic in Paraguay. High levels of ß2-microglobulin are used as prognostic markers in pathologies such as chronic lymphocytic leukemia, lymphomas, multiple myeloma, osteoarthritis, kidney diseases and AIDS but its usefulness in tuberculosis (TBC) needs further evaluation. Objectives: To evaluate whether serum level of ß2-m could allow determining the activity level of the infection acting as a marker of the evolution and therapeutic follow-up of pulmonary tuberculosis. Methodology: The first part of this work was a descriptive study with consecutive sampling, and the second part was a prospective cohort study. The serum levels of ß2-m were determined by ELISA in 22 patients with active pulmonary TBC before starting treatment and 6 months after treatment. The serum levels were also determined in 22 apparently healthy individuals as controls. Results: A statistically significant decrease was observed in the serum levels of ß2-m of the 22 patients after six months of treatment when they were compared with the levels before treatment (2.2 ± 1.0 vs 4.3 ± 2.7 µg/mL, p< 0.0001). However, the decreased ß2-m levels in the 22 patients did not reach the levels of the 22 normal control subjects (0.9 ± 0.2 µg/mL, p< 0.0000001). In 23 % (n=5) of the TBC patients, the levels decreased below the cut-off point six months after treatment. Conclusions: All patients with TBC showed increased levels of ß2-m before treatment and decreased levels after treatment without reaching the control values. A follow-up of at least one year post-treatment would allow evaluating whether the serum levels of ß2-m could be used as a marker of infection activity and indirectly as a marker of treatment efficacy.
Keywords : Mycobacterium tuberculosis; Beta 2-microglobulin; marker of infection activity.