#3033 IgA vasculitis: a unexpected diagnosis of pulmonary renal syndrome

Abstract Background IgA vasculitis is an inflammatory condition affecting blood vessels that poses a significant diagnostic and therapeutic challenge in clinical practice. Characterized by the deposition of immunoglobulin A (IgA) on vessel walls, this pathology can manifest in various ways, presenting a broad and sometimes complex clinical spectrum. Ninety percent of cases occur in the pediatric age group. Severe lung involvement, such as pulmonary hemorrhage, is rare in patients with IgAV. We present a case of a 33-year-old patient with pulmonary renal syndrome and without purpura, an atypical presentation of IgA vasculitis. Case Report We describe the case of a 33-year-old patient with no relevant medical history or regular medication, who presented to the emergency department in November 2022 with symptoms of hemoptysis, fatigue, myalgias, and pallor. On physical examination, the patient was conscious, cooperative, normotensive, tachycardic, afebrile, with bilateral axillary adenopathies, and scattered crackles on lung auscultation. Laboratory tests revealed anemia with a hemoglobin level of 5.8 g/dL, non-oliguric acute kidney injury with a creatinine level of 2.25 mg/dL, microscopic hematuria (50/hpf), and proteinuria (UPCR of 2.8 mg/mg and UACR of 1.6 mg/mg). A chest CT scan showed bilateral and scattered ground-glass opacities consistent with alveolar hemorrhage. The patient was admitted to the Nephrology service, underwent 3 sessions of plasma exchange, and started therapy with methylprednisolone 1000 mg for 3 days. A renal biopsy revealed 24 glomeruli, with 3 showing segmental sclerosis and 1 with fibrocellular crescents, mild interstitial nephritis; immunofluorescence showed IgA+++, C3++, IgM, and IgG+- Oxford Classification: M1 E0 S1 T0 C1. Bronchofibroscopy showed a rosy bronchoalveolar lavage and macrophages with hemosiderin pigment deposition. The patient continued with prednisolone at 1 mg/kg. In January 2023 (after two months), there was a 25% reduction in albuminuria with resolution of acute kidney injury. A gradual reduction of prednisolone was initiated, and it was definitively discontinued in October 2023. In the last outpatient visit in January 2024, the patient maintained normal renal function, with no hematuria, UPCR of 100 mg/g, UACR of 70 mg/g, and no further episodes of alveolar hemorrhage. Conclusion This case stands out for its atypical presentation: an adult with alveolar hemorrhage and without other more classical manifestations of IgA vasculitis, such as purpura. This is yet another case that emphasizes the importance of the broad spectrum of diagnoses that a nephrologist should consider in the face of acute kidney injury.