Kidney transplantation is strongly recommended for all patients who are medically suitable with chronic and end-stage renal disease (ESRD). Viral infection is a major problem for transplant subjects. Reactivation of viruses especially herpes viruses is associated with the strong immunosuppressive drugs. Herpes simplex virus (HSV) infection in transplant subjects, however, may become severe without treatment. Few studies have reported the presence of HSV-DNA in mononuclear leukocyte and in urine samples of renal transplant recipients. We report incidence of HSV-1 DNA in mononuclear leukocyte and in urine samples of renal transplant subjects. The results were then compared with detection of HSV-1 DNA in mononuclear leukocyte and urine samples of organ donors and in healthy volunteers as well. Fifty-five renal transplant recipients who received a living or cadaveric kidney transplant at Namazee Hospital, Shiraz University of Medical Sciences between March 2003 and June 2004 participated in the study. Peripheral blood and urine samples were collected from patients. Each individual sampled one week before up to 2 weeks post transplantation. The patients were then sampled every 4 weeks up to 52 weeks after transplantation. Urine and blood samples were also collected from 37 living donors and from 30 healthy individuals as the control groups. DNA extracted from mononuclear leukocytes and from urine specimens were processed with a polymerase chain reaction (PCR). For PCR amplification, oligonucleotide primers were selected using DNA sequences for both HSV-1 and HSV-2 thymidine kinase (TK) gene whereby primer 1 and primer 2 flank 351 base-pair fragment. Restriction enzyme endonuclease method was used for discrimination between HSV-1 and HSV-2 DNA. Patients were also examined for any signs or symptoms of renal dysfunction or other related diseases. Using PCR, HSV-1 DNA was detected in mononuclear leukocytes of 49.1% of transplant recipients and in 16.2% and 6% of living donors and healthy individuals respectively. HSV-1 DNA was only determined in urine samples of 20% of transplant recipients. HSV-2 DNA, however, was not detected in any group of subjects including renal transplant recipients. Abnormal laboratory findings such as leukocytosis, proteinuria, and haematuria, rising in serum creatinine and blood urea nitrogen (BUN) levels were documented in some patients infected with HSV-1. Hepatitis and skin lesion were also demonstrated in few cases infected with HSV-1.
Presence of HSV-1 DNA in mononuclear leukocyte of renal transplant recipients and in normal population suggests that, mononuclear leukocyte could be another site for virus latency. HSV-1 viruria, on the other hand, is a sign of viral reactivation which might progressed to generalized HSV infection. The difference observed between the number of positive HSV-1 DNA detection in leukocytes of living donors and the healthy individuals reveals that stress causes the reactivation of the HSV-1 in living donors before transplantation.