March hemoglobinuria progressed to acute kidney injury after kendo practice: a case report.

BACKGROUND: March hemoglobinuria is caused by a hemolytic mechanism due to transient hematuria after physical exercise which, although rare, may lead to acute kidney injury. We report a case of a patient with march hemoglobinuria induced by kendo, which was diagnosed by the presence of Berlin blue iron staining in the proximal tubules through renal biopsy. CASE PRESENTATION: A 15-year-old male complained of fever (37 °C), general malaise, and nausea after hard kendo sessions. Laboratory findings revealed indirect bilirubin dominant hyperbilirubinemia (total bilirubin 3.8 mg/dL), high lactate dehydrogenase (LDH), and acute kidney injury (serum creatinine: 3.11 mg/dL and estimated glomerular filtration rate: 26 mL/min/1.73m2). Urine test was positive for occult blood but without hematuria. Renal biopsy was performed to clarify the cause of renal injury, which showed minor glomerular abnormalities. Meanwhile, hemosiderin deposition was identified in the proximal tubules by Berlin blue iron staining, and lysosomes were observed to contain granular iron. In addition to clinical background of strenuous kendo exercise, renal biopsy led to a definitive diagnosis of march hemoglobinuria. CONCLUSIONS: March hemoglobinuria is a hemolytic disease that can occur after intense exercise, especially kendo. Considering its rarity due to the lack of critical symptoms, it is important to note that occult blood-positive findings may be indicative of march hemoglobinuria if the patient underwent strenuous exercise. Therefore, clinicians should be aware of this possibility to provide timely and appropriate treatment.

A rare case of alveolar hemorrhage with hypertensive emergency.

INTRODUCTION: Alveolar hemorrhage presents with severe respiratory failure, requiring prompt diagnosis and treatment. Alveolar hemorrhage is often caused by autoimmune diseases accompanied by progressive renal dysfunction. However, few cases without autoimmune diseases occur, making diagnosis difficult. Here, we report a case of alveolar hemorrhage with hypertensive emergency. PATIENT CONCERNS: A 28-year-old man presented with dyspnea and bloody sputum. His blood pressure was 200/120 mm Hg. DIAGNOSIS: The chest computed tomography showed suggestive of alveolar hemorrhage. Renal dysfunction and proteinuria were observed. However, autoantibodies were not detected. Echocardiogram revealed left ventricular function decrease. Ejection fraction was 20% to 30% with no ventricular asynergy or any valvular diseases. Brain magnetic resonance imaging showed hyperintense lesions on fluid-attenuated inversion recovery in the white matter of both cerebral and right cerebellar hemispheres, which were compatible with posterior reversible encephalopathy syndrome. Renal biopsy did not reveal any immune-mediated glomerulonephritis or vasculitis, but hypertensive nephropathy was diagnosed. INTERVENTIONS: Blood pressure was controlled with combination therapy using calcium channel blocker, angiotensin II receptor blocker, α1 blocker, and ß blocker. OUTCOMES: Alveolar hemorrhage and proteinuria improved with strict blood pressure control. CONCLUSION: This case indicates that severe hypertension can possibly cause alveolar hemorrhage. Accumulating these cases is important for general physicians to diagnose the alveolar hemorrhage with hypertensive emergency in its early stage and to avoid unnecessary treatment such as immunosuppressive therapy.

IgA Nephropathy with Gross Hematuria Following COVID-19 mRNA Vaccination.

A 28-year-old woman experienced gross hematuria after the administration of the second dose of an messenger ribonucleic acid (mRNA) vaccine (BNT162b2). She was diagnosed with Immunogloblin A nephropathy (IgAN) by a renal biopsy two weeks after vaccination, which revealed a mild increase in mesangial cells and a matrix with co-depositions of galactose-deficient IgA1 and C3 in the mesangial region. The gross hematuria and proteinuria gradually improved without any medication, suggesting that immune activation by the mRNA vaccine may not elicit continuous disease progression of IgAN. Thus, further studies investigating the relationship between mRNA vaccines against COVID-19 and the progression of IgAN should be conducted.