HDCN Article Review/Hyperlink

Webb NJA, Lewis MA, Iqbal J, Smart PJ, Lendon M, Postlethwaite RJ

Childhood steroid-sensitive nephrotic syndrome: Does the histology matter?

Am J Kidney Dis (Apr) 27:484-488 1996

The aim of this study was to investigate 1) The histologic patterns observed in nephrotic children treated with steroids who became frequent relapsers (FR) or steroid dependent (SD); 2) The clinical course of FR and SD children.

Study Design: A retrospective analysis of 51 children who underwent biopsy prior to initiation of cyclophosphamide therapy for the causes indicated above and who were followed up for a minimum of 2 years. In addition to the ususal demographic data, the main other features examined included 1) the distibution of lesions as compared to what was reported by the International Study for Kidney Disease in Childhood and by 2 other groups who undertook similar sudies; 2) the correlation between observed histologic patterns and number and frequency of relapse prior to biopsy; 3) the correlation between the frequency of relapse before institution of cyclophosphamide and response to the latter; 4) the correlation between histologic diagnosis and duration of remission after cyclophosphamide treatment.

Results: 1) A higher proportion of FSGS cases were found as compared to the ISKDC; 2) precyclophosphamide course did not correlate with histology; 3) neither of the last 2 features correlated with response to cyclophosphamide.

Conclusions: Biopsy is not necessary to decide whether or not to treat with cyclophosphamide. This decision should only be based on response to steroids not on the results of biopsy or the frequency of relapses.

Comment: Webb's paper compares apples and oranges. As noted by the authors the ISKDC study biopsied patients at presentation whereas Webb et al. report on a group of patients who were biopsied before institution of cyclophosphamide therapy, having been contemplated as a result of the patients having experienced either steroid dependence or frequent relapses. It is no surprise that such a group, with less than entirely satisfactory response to steroids, will include a higher proportion of cases of FSGS.

The reason the authors' series includes fewer cases of FSGS than others cited is probably as they pointed out partly due to the fact that their patients were still biopsied relatively close to the onset of their disease (8 months vs 6 years). Biopsies performed years into the course of the disease would be expected to be less susceptible to the sampling problem inherent in the diagnosis of FSGS because the kidneys then would have a large proportion of sclerotic glomeruli. One does not need to evoke the hypothetical and difficult to prove idea of evolution of minimal change disease over time to FSGS.

Although the number of cases of FSGS with complete follow up was small, 5 out of 41 cases only, these few patients' response to cyclophosphamide seems to have been as favourable as that of patients with less significant lesions. In our population we see essentially no prolonged remission following cytoxan in FSGS. (Samy S. Iskandar, MBBCh, PhD, Bowman Gray School of Medicine, Winston-Salem, NC)