1 Division of Nephrology, Medical Centre Arabkir, Yerevan, Armenia 2 Republican Centre of Paediatric Pathology, Yerevan, Armenia 3 Division of Nephrology, University Children's Hospital, Zurich, Switzerland
Sir,
We have read with interest the Letter to the Editor by Simsek and colleagues [1] reporting the efficacy of colchicine in a nephrotic paediatric patient with amyloidosis due to familial Mediterranean fever (FMF) with resolution of proteinuria. Several studies have clearly shown the effect of colchicine in the prevention of amyloidosis, but once the kidney is involved it is disputed whether this treatment could still alter the progression of renal disease. There are anecdotal reports on the successful treatment at the late stage of renal amyloidosis, however these are mainly on adults [2,3] and very few on paediatric patients [4,5]. Reversal of the nephrotic syndrome was noticed by Hojberg and Mertz [4] in two brothers (aged 6 and 10 years) with FMF and amyloidosis proven by rectal biopsy: one of them had complete remission. Majeed et al. [5] observed the disappearance of proteinuria in two children with FMF. However, these two patients were not nephrotic, and no biopsy had been performed, so the authors could only assume, but not prove, that they indeed had renal amyloidosis.
We have observed three paediatric patients who seem to support the observation of Simsek et al. [1]. All threetwo girls and one boy, aged 1115 yearspresented only at the nephrotic stage of FMF with serum albumin 820 g/l and with proteinuria of 39 g/24 h; serum creatinine was still in the normal range (5163 µmol/l). Amyloidosis was confirmed by renal biopsy in each of them. Therapy with colchicine (1.8 mg/day) was initiated and was continued during the follow-up period of 5569 months. These three patients did not only maintain good renal function, but in addition had full reversal of the nephrotic syndrome within 316 months with disappearance of proteinuria (trace to 0.066 g/l) at 2640 months. They remained proteinuria free during the further follow-up of 1530 months.
Thus, there still is a chance of reversal of the nephrotic syndrome when therapy with colchicine is initiated only at the nephrotic stage of renal amyloidosis. However, this response is not predictable. Indeed, we have only seen a moderate (or no) response to colchicine administration in several other cases who started treatment similarly late. Obviously, treatment with colchicine should be started as early as possible in the course of FMF.
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