FINE-NEEDLE ASPIRATION BIOPSY ALLOWS EARLY DETECTION OF ACUTE REJECTION IN CHILDREN AFTER RENAL TRANSPLANTATION 1

Background. Acute rejection is still a major diagnostic problem after renal transplantation and remains an important cause of graft loss. Diagnosis of acute rejection is mainly based on clinical signs and the renal core biopsy findings. In adults fine-needle aspiration biopsy (FNAB) has proved to be a sensitive method in diagnosing acute rejection. Methods. In this study we retrospectively analyzed our data on the routine use of FNAB after 83 kidney transplantations in 78 children of different ages. Results. A total of 984 FNABs were taken during the postoperative hospitalization with a mean of 12 biopsies per patient. Of the biopsies 93% were representative, and no major complications occurred. Sixty-five rejection episodes were diagnosed and treated in 47 patients (57%). The FNAB analysis detected rejections often before clinical signs. Half of the patients had increased serum creatinine concentration and 38% had fever at the time of rejection diagnosis. Both signs were present in only 19% of the episodes. A decrease in urine output (>20%) was seen in a third of the episodes. The rejections responded well to oral methylprednisolone (3 mg/kg/day), and lymphoglobulins were needed in only 12% of the episodes. More than 90% of the rejections were completely reversible and no transplant was lost because of acute rejection. Conclusion. The results indicate that FNAB is a safe and sensitive method for the diagnosis and follow-up of acute cellular rejection in pediatric recipients of different ages.