Renal Impairment of Proximal Tubular Injury Caused by Red Yeast Rice Supplement: Report of 2 Cases.

Introduction: Drug-induced tubulointerstitial injury is a common cause of renal impairment. Since the mechanisms of drug-induced tubular injury are diverse, various treatment approaches are needed according to the pathogenesis. Renal biopsy is indispensable to determine not only the pathological diagnosis, but also the underlying mechanism, and to guide appropriate treatment. Most recently, one of the red yeast supplements has been widely highlighted as a novel cause of tubular damage, mainly in Japan and Asia. However, neither detailed pathological findings nor the mechanism of renal impairment has been sufficiently reported. Case Presentation: Two cases of renal impairment after taking red yeast supplement internally are presented. Both cases showed renal dysfunction with low uric acid, potassium, and phosphorus levels, characteristic features of Fanconi syndrome. The renal biopsy findings of both cases showed severe injury to the proximal tubules with mild inflammatory cell infiltration. The proximal tubules exhibited diffuse loss of the brush border, flattening, and tubular lumen dilation. Immunofluorescence showed no deposition of immunoglobulin and complement in the glomeruli and tubules. Electron microscopic findings indicated proximal tubular damage without crystal deposition. Moreover, immunohistochemistry using the proximal tubular marker CD10 and a marker for distal tubules including the loop of Henle, E-cadherin, collectively demonstrated that the focus of renal injury in both cases was mainly the proximal tubules. Conclusions: The red yeast rice supplement itself, its metabolized product, or other unknown contaminant components might directly induce proximal tubulopathy rather than an allergic reaction-related tubulointerstitial nephritis.

[Acute leukemia developing in the second trimester of pregnancy].

Acute leukemia (AL) during pregnancy poses a substantial risk to both mothers and fetuses. Treatment for leukemia should be initiated promptly; however, the management of AL in pregnant women and fetuses is usually challenging, especially during the second trimester. Here, we report two cases of AL that developed during the second trimester of pregnancy. In one case, chemotherapy was initiated while continuing the pregnancy; in the second case, a cesarean section was performed prior to chemotherapy initiation. As per current medical records, both infants are thriving without any medical problems. The optimal strategy for the treatment of AL during pregnancy typically includes chemotherapy after delivery. However, if fetal development is not sufficient for ex utero survival, the only alternatives available are the initiation of treatment while continuing the pregnancy or treatment after therapeutic abortion (if it is legally allowed). According to previous studies and as per the results from our first case, the initiation of chemotherapy while sustaining the pregnancy may be an acceptable option if it is conducted with appropriate informed consent. The treatment of AL in the second trimester of pregnancy should be carefully decided, while taking into account the medical, legal, and social aspects, such as gestational weeks, maternal and fetal status, and wishes of the patients and their families.