Mediators of inflammation correlate with microalbuminuria in patients with non-Hodgkin's lymphoma.

Recent studies have demonstrated a high frequency of minor glomerular leakage of albumin in cancer patients. Pathogenic mechanisms of increased urinary albumin excretion (UAE) in malignancies remain to be clarified. We have attempted to identify whether microalbuminuria in lymphoma patients is associated with inflammatory mediators and the acute-phase response. UAE, urinary excretion of beta2-microglobulin and IgG, and serum levels of interleukin 6 (IL-6), tumour necrosis factor alpha (TNF-alpha) and C-reactive protein (CRP) were determined in 113 patients with newly diagnosed non-Hodgkin's lymphoma. We demonstrated a high frequency of microalbuminuria (>or= 20 microg/min) and UAE correlated strongly with serum levels of CRP, IL-6 and TNF-alpha. UAE, CRP, IL-6 and TNF-alpha were significantly higher in patients with advanced disease stage, B symptoms and in high-risk patients according to the International Prognostic Index. Urinary excretion of beta2-microglobulin was unaffected in patients with increased UAE. However, UAE was significantly correlated with urinary excretion of IgG, suggesting an altered size selectivity of the glomerular filtration barrier. This is the first study that shows a direct correlation between microalbuminuria and proinflammatory cytokines in malignancies, indicating a pathogenic relationship between inflammation and glomerular leakage of albumin. Future efforts should focus on the pathophysiological cause-effect mechanisms and larger studies are needed to confirm the clinical significance of UAE.