Case Presentation: A 43 year-old-woman with no known medical history presented with two months intermittent fever, cough, pleurisy, hematuria, and weight loss. On exam she had diffuse crackles and lower extremity edema. The patient was intubated for respiratory distress. Laboratory workup revealed acute anemia and urinalysis consistent with nephritic syndrome. Chest x-ray showed bilateral diffuse opacities and subsequent CT scan showed centrilobular ground-glass opacities and consolidation. Bronchoscopy was indicative of diffuse alveolar hemorrhage. The patient also developed rapidly progressive renal failure and was started on pulse dose steroids. Autoimmune evaluation showed ANA 1:320 speckled pattern, MPO-ANCA+, and PR3-ANCA+. Renal biopsy revealed class IV diffuse lupus crescentic nephritis as well as necrotizing crescentic glomerulonephritis consistent with a concomitant ANCA-associated glomerulonephritis. The patient was diagnosed with systemic lupus erythematosus and antineutrophilic cytoplasmic antibody (ANCA)-associated vasculitis (SLE/AAV) overlap syndrome and received five sessions of plasma exchange with nearly complete resolution of symptoms. She was discharged on a slow prednisone taper with outpatient follow-up.

Discussion: Pulmonary-renal syndrome (PRS), a combination of diffuse alveolar hemorrhage and rapidly progressive glomerulonephritis, is a broad disease category with many distinct entities. SLE/AAV overlap syndrome is a fairly new entity in the PRS category that usually has a severe initial presentation, with both vital and functional prognoses being poor. When managing a patient with diffuse alveolar hemorrhage and suspected lupus, awareness of this syndrome should prompt a thorough and early evaluation, as these patients have presence of both ANA and anti-MPO antibodies. Treatment includes corticosteroids and cytotoxic agents. Early initiation of plasma exchange has been shown to improve renal recovery and decrease progression to ESRD, although the long-term benefit of mortality remains unclear.

Conclusions: Awareness of SLE/AAV overlap syndrome should prompt early evaluation for both ANA and ANCA when managing patients with lupus and atypical symptoms, including intra-alveolar hemorrhage.