Altered systemic levels of acute phase proteins in tuberculous lymphadenitis and modulation after treatment

BACKGROUND: Pulmonary tuberculosis (PTB) is characterized by elevated levels of acute phase proteins (APPs), but their association with tuberculous lymphadenitis (TBL) is poorly studied. METHODS: We examined the systemic levels of APPs (alpha-2-macroglobulin [⍺-2MG], serum amyloid A [SAA], C-reactive protein [CRP] and haptoglobin [Hp]) in TBL, PTB, latent tuberculosis (LTB) and healthy controls (HC) at baseline and in TBL after the completion of anti-tuberculosis treatment (ATT). We have also examined the association of these proteins with lymph node (LN) size, culture grade and multiple versus single LN involvement. RESULTS: TBL individuals exhibited increased systemic levels of ⍺-2MG, SAA, CRP and Hp in comparison to HCs and increased CRP levels in comparison to LTB individuals. TBL individuals also exhibited decreased systemic levels of Hp compared to PTB individuals. APPs were not significantly associated with LN size, LN involvement and culture grade, indicating a lack of association with disease severity. Following ATT, post-treatment levels of ⍺-2MG, CRP and Hp were significantly diminished compared to pre-treatment levels. CONCLUSION: TBL disease is characterized by altered levels of APPs at baseline and modulated following treatment, indicating the presence of systemic inflammation.