Presented at:
American Transplant Congress, Washington, DC,
June 3, 2003
Am J Transpl 3 Suppl 5: 441, 2003.
Measurement Of mRNA For Granzyme B In Urine In The First Week Of Renal Transplantation Predicts Clinical As Well As Histological Outcome
Priya Anantharaman, Darshana Dadhania, Thangamani Muthukumar, Meredith Aull, Surya Seshan, Choli Hartono, David Serur, Ruchuang Ding, Baogui Li, Sandip Kapur, Manikkam Suthanthiran
Div of Nephrology,Dept of Medicine & Transplantation Medicine, Weill Medical College of Cornell University, New York, NY; Dept of Pharmacy, Weill Medical College of Cornell University, New York, NY; Dept of Pathology, Weill Medical College of Cornell University, New York, NY; The Rogosin Institute, New-York Presbyterian Hospital, New York, NY; Dept of Surgery, Weill Medical College of Cornell University, New York, NY
A non-invasive test that predicts clinical and histological quiescence would be of value in clinical renal transplantation. It has been demonstrated that measurement of mRNA for cytotoxic attack proteins granzyme B and perforin in urinary cells is a non-invasive means of diagnosing acute rejection (Li et al. NEJM 2001). Herein, we investigated the utility of measuring mRNA for cytotoxic T lymphocyte specific protein granzyme B in 47 urine specimens. 14 of 47 urine specimens were obtained in first week of transplantation from 14 recipients with stable renal function (stable patients). These patients were entered in a steroid free immunosupression trial and they underwent protocol biopsies at 1 and 3 months post- transplantation. The remaining 33 specimens (29 recipients) were collected at the time of biopsy confirmed acute rejection (acute rejection patients). Total RNA was isolated from urinary cells and 1 ug was reverse transcribed to cDNA. Granzyme B mRNA was measured by using real-time quantitative PCR assay.Our studies demonstrated the following: (1) mRNA levels of granzyme B in the 14 urine specimens obtained in the first week of transplantation from the 14 stable patients were significantly lower compared to granzyme B mRNA levels in the 33 specimens (29 patients) obtained at the time of biopsy confirmed acute rejection (7.25 X 103 vs. 3.73 X 105 copies/ug of RNA; P<0.0001);(2) 13 of 14 stable patients had granzyme B mRNA levels below the acute rejection cutoff value of 24,600 copies/microgram of total RNA;(3) 13 of 14 stable patients with granzyme B mRNA levels below the acute rejection threshold value did not experience clinical rejection in the first 6 months of transplantation;(4)13 of the 14 stable stable patients with granzyme B mRNA levels below the acute rejection threshold value did not show histological features of acute rejection in protocol biopsies performed at 1 month and 3 months of transplantation; and;(5) the only stable patient with granzyme B mRNA levels above the acute rejection threshold experienced an acute rejection at 6 months post-transplantation. Our findings support the idea that measurement of mRNA levels for granzyme B in the first week of renal transplantation is useful for the prediction of not only clinical but also histological quiescence.