LAUSR

An 8-year-old girl previously diagnosedwith Henoch–Schönlein purpura (HSP) was referred to the pediatric nephrology department of our institution to explore nephrotic proteinuria and macroscopic hematuria. She had no other personal medical history. The current medical history started when she presented a shortduration episode of acute abdominal pain associated with vomiting and fever. Her parents also reported concomitant pallor and jaundice. Clinical evolution was spontaneously favorable, with no need for medical consultation. Severe abdominal symptoms recurred 3 months later associated with ankle-located pain, macular skin rash, and edema. Henoch–Schönlein purpura (HSP) was suspected based on the association of recurrent abdominal pain, ankle joint arthralgia, and skin rash. Surprisingly, blood test results illustrated the presence of hemolytic anemia (Hb 8 g/dl, undetectable serum haptoglobin, lactic acid dehydrogenase [LDH] level: 640 UI/L). However, laboratory investigation of its pathogenesis was not contributive (Table 1). No signs of auto-immunity were identified. Microangiopathy was excluded as platelet count was normal and schizocytes were absent. Screening for infectious diseases was negative and no morphological abnormalities of erythrocytes were revealed. Of note, liver and kidney function were normal; urine analysis detected neither proteinuria nor hematuria. On the other hand, an iron test highlighted severe iron deficiency (serum ferritin: 10 ng/ ml). The patient received high-dose intravenous iron infusion during hospitalization and was discharged on a regimen of prednisone at a starting dose of 2 mg/kg/day. All symptoms disappeared after steroid initiation and hemoglobin level normalized. Two relapses of abdominal pain occurred after decreasing steroid therapy. During the second relapse, the patient also presented dark colored (brown) urine. She was then referred to the pediatric nephrology department of our institution for further investigation. On initial examination, the patient was pale and icteric with no signs of acute abdomen. Edema and arterial hypertension were not observed. The laboratory results revealed nephrotic-range proteinuria (urine protein: 3.94 g/L, urine protein/creatinine ratio: 320 mg/mmol) with normal serum albumin (serum albumin: 4 g/dl), hematuria on urinary dipstick and normal renal function. A renal biopsy was carried out and the results are shown below (Fig.1).