Expression of C-reactive protein by renal cell carcinomas and unaffected surrounding renal tissue

Kidney Int. 2005 Nov;68(5):2103-10. doi: 10.1111/j.1523-1755.2005.00666.x.


Background: Elevation of plasma C-reactive protein (CRP) is common in patients with renal cell carcinoma (RCC). Renal tubular epithelial cells are capable of synthesizing CRP. Although production of interleukin (IL)-6 has been described in RCC, CRP expression by carcinoma cells has yet not been investigated.

Methods: In the present study we analyzed CRP plasma levels as well as intratumoral CRP and IL-6 expression of RCC from 40 patients who underwent radical nephrectomy by means of quantitative real-time polymerase chain reaction (PCR) and immunohistochemistry. For each tumor, specimens were obtained from tumor center, tumor margin, and unaffected surrounding renal tissue.

Results: Preoperative plasma CRP levels correlated significantly with tumor stage (P = 0.05) and grade (P < 0.01). CRP mRNA expression was detected in 26 of 33 (79%), 30 of 36 (83%), and 32 of 36 (89%) samples from tumor center, tumor margin, and unaffected surrounding tissue, respectively. However, levels of CRP mRNA were significantly higher in tumor tissue compared to adjacent renal tissue (P < 0.01). Clear cell carcinoma exhibited significantly higher CRP mRNA levels than papillary carcinoma (P < 0.05). CRP plasma levels correlated significantly with quantitative levels of CRP mRNA within tumors (P < 0.0001). Immunohistochemically, strong CRP production was observed both in tumor cells and in tubular epithelial cells in unaffected tissue, respectively. All kidneys expressed IL-6 mRNA in the tumor and/or the unaffected tissue, but levels of intratumoral IL-6 mRNA showed no significant correlation with CRP plasma levels or local CRP transcription.

Conclusion: In patients with RCC, a tumor-derived origin of some plasma CRP is likely. Activity of the IL-6/CRP network in RCC contributes to the accumulating evidence of the acute-phase reaction as a local inflammatory process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute-Phase Reaction
  • Adult
  • Aged
  • Aged, 80 and over
  • C-Reactive Protein / genetics
  • C-Reactive Protein / immunology
  • C-Reactive Protein / metabolism*
  • Carcinoma, Renal Cell / immunology*
  • Carcinoma, Renal Cell / metabolism*
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Immunohistochemistry
  • Interleukin-6 / blood
  • Interleukin-6 / genetics
  • Interleukin-6 / immunology
  • Kidney Neoplasms / immunology*
  • Kidney Neoplasms / metabolism*
  • Male
  • Middle Aged
  • RNA, Messenger / analysis


  • Interleukin-6
  • RNA, Messenger
  • C-Reactive Protein