Does infiltration of neutrophils in peritubular capillaries indicate humoral rejection? A case displaying a characteristic lesion of a significantly high amount of neutrophils in peritubular capillaries at 1‐h graft biopsy during transplant operation

Abstract
Inagaki H, Takeda A, Sato T, Watanabe I, Katayama A, Haba T, Tominaga Y, Uchida K, Oikawa T, Morozumi K. Does infiltration of neutrophils in peritubular capillaries indicate humoral rejection? A case displaying a characteristic lesion of a significantly high amount of neutrophils in peritubular capillaries at 1‐h graft biopsy during transplant operation. Clin Transplantation 2001: 15 (Supplement 5): 35–40. ©Munksgaard, 2001 We present a case report of a 50‐yr‐old Japanese woman with a significant accumulation of neutrophils in the peritubular capillaries (PTC) and severe acute tubular necrosis (ATN) at 1‐h allograft biopsy during transplant operation from cadaver donor after a cardiac death. Significant accumulation of neutrophils in the PTC is usually valuable diagnostically for acute humoral rejection. However, the patient showed no clinical signs of acute rejection. A second graft biopsy performed on the fifth postoperative day (POD) revealed that both infiltration of neutrophils in PTC and ATN lesions were more aggravated. Neither clinical course nor other morphological findings were compatible with humoral rejection. After the third biopsy of POD 27 revealing acute vascular rejection of moderate degree, acute rejection therapy using methylprednisolone pulse therapy and OKT‐3 therapy was performed. Consequently, after a period of delayed graft function requiring haemodialysis for approximately 4 wk, graft function was restored and serum creatinine decreased to 2 mg/dL. Later, we were able obtain information from a paired graft from the same donor. Significant accumulation of neutrophils in the PTC similar to our recipient was also noted in a 1‐h biopsy specimen of the paired kidney. This confirmed that the accumulation of neutrophils in the PTC noted in two recipients was transmitted from the donor kidney. The pathogenesis and clinical significance of neutrophils in the PTC has been shrouded in mystery.