1 Department of Nephrology and 2 Unit of Transplantation, Tel-Aviv Sourasky Medical Center, Affiliated to the Sackler Faculty of Medicine, Tel Aviv University, Israel
Sir,
Alport's syndrome (AS) is relatively common and may cause end-stage renal failure for which there is no preventive treatment. Kidney transplantation for AS has been performed, although the appearance of anti-GBM antibodies following surgery has been reported. The advisability of allowing an asymptomatic or oligosymptomatic mother to donate a kidney to her son who was suffering from end-stage renal failure caused by AS is the subject of this letter.
Case.
A 21-year-old male, suffering from AS and mild hypertension was assessed for kidney transplantation. The diagnosis of AS was made on the basis of renal failure, neurosensorial hearing loss, family history, and a kidney biopsy performed at 4 years of age.
The prospective donor was the patient's 44-year-old mother who was most probably a carrier of the Alport gene without hearing or sight disturbances. Her urinalysis showed microscopic haematuria, whilst kidney function tests were completely normal. An isotope kidney scan was also normal. Both patient and mother were advised as to the possible implications involved.
At the time of transplantation the patient's serum creatinine level was 7 mg/dl, BUN 96 mg/dl, creatinine clearance 10.2 ml/min and haemoglobin 9.1 g%. The urinalysis revealed microscopic haematuria and non-nephrotic proteinuria. The patient was not on dialysis.
Following surgery, the patient received the routine treatment including cyclosporin A, prednisone, and azathioprin. He also received prophylactic treatment with acyclovir and trimetaprim-sulfamethoxazol.
On the fifth postoperative day his serum creatinine level decreased to 1.4 mg/dl, BUN to 19 mg/dl and urinalysis was normal.
During the third week following transplantation, the creatinine level rose to 2 mg/dl and microhaematuria appeared. The level of cyclosporin A was normal.
A graft biopsy was performed, and light microscopy revealed focal superficial mottling of the GBM, one focus showed basket-weaving feature (as described for AS [1]). Endothelial and epithelial cell alterations were not found. There were no signs of rejection.
Creatinine level stabilized at 1.9 mg/dl, microhaematuria persisted without proteinuria.
During a 54-month follow-up period, kidney function tests remained stable and urinalysis remained unchanged. The patient has not suffered from any intercurrent illness and he continues to receive the same medications.
The transplanted kidney ultrasound examination was performed 30 months post-surgery and showed no pathological findings. A Doppler test showed normal blood flow in the renal artery.
After nephrectomy, an isotope scan of the mother's kidney showed a functional compensation; there was no proteinuria, or hypertension, only microscopic haematuria. The recipient had no documented specific morbidity after a 54-month follow-up, and kidney function was stable.
Discussion.
The incidence of AS is approximately 1:5000 [1]. About 85% of the cases with AS are X-linked and the rest are either autosomal-recessive or dominant.
Approximately 0.5% of the European dialysis population suffer from AS [1]. Despite the fact that kidney transplantation is generally successful in such patients [2], rapidly progressive glomerulonephritis and anti-GBM antibodies have been described. In 20% of cases, a biopsy of the transplanted kidney revealed linear deposits of IgG [2].
The information on living donor transplantation for AS patients is limited to a few cases. In an EDTA report [1] from 1996, the number of living donors for AS is lower than for patients with other causes of end-stage renal failure patients, but no specific information is given about this group of patients. In one report [3], two brothers with end-stage renal failure, due to AS, received organs from their parents. One brother received a kidney from his mother, who was certainly an AS carrier. Both donor and recipient had a good outcome. Peten et al. [4] described two additional living-donor AS recipients.
We describe the successful transplantation of a kidney in a young AS patient. The donor was the patient's mother, who was most probably a carrier of the Alport gene. Prior to transplantation, the mother had normal kidney function but persistent microhaematuria. It was demonstrated that both the mother's kidneys were affected; there was therefore a questionable risk to her health. The microscopic haematuria could also be a sign of glomerular disease. Moreover, the fact that a not entirely healthy kidney was to be transplanted was clearly noted in the informed consent.
Whether immunosupressive drug-related nephrotoxicity, ischaemia, and hypertrophy following transplantation would affect the AS kidney function was not fully known.
Our case would appear to confirm Kashtan's opinion [5] that in special cases, young patients with AS and end-stage renal failure may receive a kidney from their mothers, who are AS carriers with normal renal function. The strong desire of such mothers to donate kidneys may influence the medical decision. We would, however, emphasize that proteinuria, ocular symptoms, deafness, and/or wide basket-weave transformation represented potential risk factors for the mother, even though the kidney function was satisfactory pre-operatively.
We suggest that it is not necessary to perform kidney biopsies in mothers or sisters of AS patients with normal kidney function and only minimal urinary changes (microhaematuria) in the absence of extrarenal symptoms or signs prior to donation.
References