Authors' reply: Serum Albumin for Tuberculosis in HIV Infected Patients Eligible for Antiretroviral Therapy.

We thank Professor Wiwanitkit for highlighting important aspects of hypoalbuminemia in HIV infected patients.1 Hypoalbuminaemia can be the result of inadequate protein intake, malabsorption, reduced production in the liver, increased catabolic state or increased excretion of proteins through the kidneys. In patients with chronic diseases such as cancer, tuberculosis or end stage renal disease, hypoalbuminemia can be explained by a reduced protein intake due to anorexia and by an increased catabolic state due to inflammation. However, recent evidence shows that hypoalbuminemia is more likely to be a marker of inflammation than a marker of malnutrition, and nutritional supplementation is unlikely to raise serum albumin levels.2 HIV infection produces chronic inflammation. Hence, HIV could be a cause of hypoalbuminemia and one could expect a correlation between serum albumin concentrations and CD4 cell counts. However, Sudfeld et al did not observe an association between serum albumin levels and changes in the CD4 cell counts, and the CD4 cell counts did not affect the value of serum albumin for predicting mortality.3 It is possible that hypoalbuminemia could be a marker of inflammation in HIV infected patients and could be used as a predictor of mortality independent of the CD4 cell count.4 Whether the inflammation is produced by HIV itself or by co-infections such as tuberculosis is a matter that deserves further research. The objective of our study was not to explain the causes of hypoalbuminemia in HIV infected patients, but to explore the usefulness of hypoalbuminemia as a predictor of tuberculosis.5 The vast majority of HIV infected patients with tuberculosis are living in lowand middle-income countries, where the smear microscopy of sputum is most of the time the only available highly specific diagnostic test.6 In our setting, three-quarters of patients diagnosed with tuberculosis had smear negative sputum.7 Even in settings where the Xpert RIF/MTB assay is available, empirical treatment is the rule.8,9 Our study suggested that serum albumin could be useful for clinicians working in resource-poor settings when facing smear-negative HIV infected patients with clinical suspicion of tuberculosis. Patients with hypoalbuminemia will be more likely to have tuberculosis. Patients with higher albumin concentrations are less likely to have tuberculosis and, Received: 4 Dec. 2013, Revised: 10 Dec. 2013, Accepted: 14 Dec. 2013, ePublished: 16 Dec. 2013