CONCORDANCE OF TWO CORES, TWO CLASSIFICATIONS (BANFF 97 AND CCTT ) AND TWO RESEARCHERS' DIAGNOSIS IN RENAL ALLOGRAFT NEEDLE BIOPSES

Histological diagnosis and grading of acute renal allograft rejection does not always correlate with the clinical course and response to treatment. This may be due to inadequate sampling. But lack of objectivity in histological criteria used for diagnosis and grading causes a lack of understanding between pathologists. This may be a confounding factor as well. In this study, we compared the objectivity of the criteria of Banff classification (1997) and CCTT system and also searched concordance of histopathological findings between the biopsy cores. 

Two independent observers, unaware of each other, other core and clinical course or original histological diagnosis, reviewed slides of 170 cores of 85 renal allograft biopsies from 65 cases. Each core had been assessed for the absence or presence and type of rejection by using Banff 97 and CCTT classification. Between the two observers; the agreement rate, kappa and weighted kappa values were found respectively %84, 0.62 and 0.59 for Banff 97 classification and %79, 0.54 and 0.58 for CCTT classification. The concordance of two cores, kappa and weighted kappa values were found respectively %81, 0.61 and 0.56. 

Reproducibility of both classifications, histologically was near the same. Obtaining two cores of biopsy is essential for a reliable diagnosis. However mentioning sensitivity and specificity rates between two classifications require some further studies which include comparative knowledge of clinical diagnose, respond to treatment and course.