Sir,

We would like to respond to the letter from Dr. Fujinaga and colleagues in which they report on the clinical outcomes of children with heavy non-nephrotic proteinuria associated with Henoch–Schönlein purpura nephritis, disease relapse, their initial therapies, and the importance of long-term follow-up [1].

The long-term outcomes of Henoch–Schönlein purpura (HSP) depend on renal involvement, referred to as Henoch-Schönlein purpura nephritis (HSPN). In our study, we retrospectively analyzed the records of 110 children with HSPN, of whom 42 patients had a nephrotic state [2]. The long-term outcomes of HSPN patients presenting with a shorter duration of nephrotic state and without immunosuppressive treatment are not necessarily serious. Ninchoji et al. reported that aggressive drug therapies, particularly combination therapies comprising prednisolone, immunosuppressants, warfarin, and dipyridamole, are unnecessary for the treatment of moderate HSPN [3]. We are also apprehensive about the possibility of patients becoming over-treated through the administration of immunosuppressants containing steroids in cases diagnosed only as nephrosis with HSPN. Therefore, in our study, we focused on the continuation of a nephrotic state and analyzed children with HSPN presenting with a nephrotic state.

However, our study was not a controlled trial, and we selected treatments that were considered suitable for the patients’ conditions. A randomized controlled study is needed to determine the efficacy of treatment in patients with moderate or severe types of HSPN.

Fujinaga et al. also defined the relapse of HSPN as the reappearance of urinary protein excretion (protein/creatinine ratio >0.5) after a proteinuria-free period of more than 6 months [1]. However, they did not mention the appearance of hematuria. The appearance of proteinuria might be caused by damage from the first nephritic attack, rather than indicating the relapse of nephritis. In our study, some patients did suffer from relapses of proteinuria and hematuria, and a few of these did require immunosuppressive therapy to treat the relapse. Of course, we do agree that long-term follow-up should be required for all patients who present with nephrotic proteinuria.