Immunosuppressive acidic protein detects high nuclear grade localized renal cell carcinoma.

Objectives: To identify a potentially useful preoperative predictor of high nuclear grade renal cell carcinoma (RCC).

Methods: Our investigation consisted of 181 patients with histologically confirmed clear cell RCC. The positive predictive value, sensitivity, and specificity for detecting nuclear grade RCC were calculated individually for the largest tumor diameter. Hemoglobin, alkaline phosphatase, C-reactive protein, ferritin, and immunosuppressive acidic protein (IAP) levels were also determined in all patients preoperatively.

Results: The distribution of patients by nuclear grade was 74 patients (41%) with grade 1, 75 (41%) with grade 2, and 32 (18%) with grades 3 and 4. With respect to sensitivity, tumor diameter detected 28 (87.5%) of 32 high nuclear grade RCC specimens, and hemoglobin, C-reactive protein, alkaline phosphatase, ferritin, and IAP detected 10 (31.2%), 25 (78.1%), 8 (25.0%), 16 (50%), and 27 (84.3%) of 32, respectively. Multiple logistic regression analysis showed that a higher than normal C-reactive protein and IAP was associated with a 252% and 405% increase in the odds of a high nuclear grade, respectively. In the Stage T1 cases, elevated IAP was also associated with a 989% increase in the odds of a high nuclear grade.

Conclusions: IAP level may be a useful predictor for detecting high nuclear grade localized RCC preoperatively.