San Diego, CA USA (UroToday.com) B-lymphocytes are important antigen-presenting cells. There are several reports in the literature on the association of ccRCC and lymphoma of B cell origin. Therefore, the group theorized that B-cells may be atypically distributed in ccRCC and may be associated with poor outcomes.
Blood samples were obtained from RCC patients before partial or radical nephrectomy and age-similar non-cancer controls. Flow cytometry was performed and data was quantified as mean fluorescence intensity (MFI) or % cells that express a biomarker. Patients were excluded if they had comorbid CLL, prior surgeries for RCC, non-ccRCC histology. B-cells were defined as CD45+/CD19+ and further characterized with other markers. Low B-cell count was defined to be below the first quartile level (141 cells/μl) in the healthy donors.
ccRCC patients and healthy donors had similar distributions of BL count [median 170/μl (28-679) vs. 189/μl (83-408), p = 0.49]. With median follow-up of 41 months (1-55 mo), 10 patients died with ccRCC. Patients with BL < 141/μl had lower CSS compared to patients with BL > 141/μl (p = 0.0013). This was seen in also in otherwise localized ccRCC patients. In a multivariable analysis, this was significant with adjustment for T-stage and non-localized disease. Compared to healthy non-cancer controls, B-lymphocytes in ccRCC had higher percentages of CD27+ phenotype and lower percentages of CD20% cells.
The group concludes that in patients with ccRCC, low B-lymphocytes is prognostic of poor cancer survival. Furthermore, B-lymphocytes are atypically differentiated compared to non-cancer healthy controls.
Presented By: Mohammed Haseebuddin, MD