Amyloid deposition in granuloma of tuberculosis patients: A pilot study

Abstract

The formation of granuloma is one of the characteristic feature of tuberculosis. Besides, rise in the concentration of acute phase response proteins mainly serum amyloid A is the indicator for chronic inflammation associated with tuberculosis. Serum amyloid A drives secondary amyloidosis in tuberculosis and other chronic inflammatory conditions. The linkage between serum amyloid A (SAA) protein and amyloid deposition site is not well understood in tuberculosis and other chronic inflammatory conditions. We hypothesized that granuloma could be a potential site for amyloid deposition because of the presence of serum amyloid A protein and proteases that cleave SAA and trigger amyloid formation. Based on this hypothesis, for the first time we have shown the presence of amyloid deposits in the granuloma of tuberculosis patients using the gold standard, Congo red dye staining.