SESSION TITLE: Critical Care Student/Resident Case Report Posters IV
SESSION TYPE: Medical Student/Resident Case Report
PRESENTED ON: Tuesday, October 29, 2013 at 01:30 PM - 02:30 PM
INTRODUCTION: Microscopic polyangiitis (MPA) is one of the ANCA associated vasculitis that affects small vessels. Systemic manifestations of MPA are more common than pulmonary manifestation, with reported glomerulonephritis in 97% and diffuse alveolar hemorrhage (DAH) in 30% of the cases (1). Lung biopsies typically show pulmonary hemorrhage, hemosiderin laden macrophages in alveolar spaces and neutrophilic capillaritis (2).
CASE PRESENTATION: 56 year old white man presented with progressive dyspnea, without cough, hemoptysis or fever. His medical history was positive for obesity, diabetes mellitus, coronary artery disease, hepatitis C and chronic kidney disease. Physical examination was remarkable for hypoxemia, diffuse crackles, and 1+ lower extremities edema. Chest-X-ray and CT scan (Figure 1) revealed significant bilateral consolidations, primarily on the left, with subpleural sparing. Laboratory workup revealed a WBC count of 8500/cm3 (85% neutrophils, 10% lymphocytes, 0.7 % eosinophil). Hemoglobin level was 6.6g/dl (down from a baseline of 10g/dl) . Creatinine was at baseline of 2.1 mg/dl. Urine analysis revealed no red blood cell cast. Due to increased oxygen requirement, the patient was placed on mechanical ventilation. Bronchoscopy revealed increasingly hemorrhagic fluid on sequential bronchoalveolar lavage. Serology workup revealed high C-ANCA (175 U/ml, normal <15 U/ml), P-ANCA of 4U/ml (normal< 15 U/ml), with normal anti-GBM ANA and cryoglobulins. The patient was started on pulse dose steroids and plasmapheresis. Despite therapy, the patient’s respiratory failure continued to worsen and the family decided to withdraw care. Autopsy revealed diffuse pulmonary hemorrhage secondary to microscopic polyangiitis, with no extrapulmonary involvement and no granulomatous inflammation. There was predominant mononuclear cellular infiltration of the alveolar septa with absence of the classical neutrophilic capillaritis (Figure 2).
DISCUSSION: This case demonstrates a deviation from the classical manifestation of microscopic polyangiitis. It was limited to the lungs with no renal or systemic involvement, and was associated with a C-ANCA serology, which is more commonly found in Wegener’s granulomatosis. Another atypical feature was the monocytic predominance in the alveoli, rather than the classical neutrophilic capillaritis.
CONCLUSIONS: Our case describes a variant of MPA that is limited to the lung with monocytic alveolar wall infiltration. Further studies are needed to confirm similar pattern.
Reference #1: 1- Jennette J et al: small-vessel vasculitis. N Engl J Med 1997; 337:1512-1523
Reference #2: 2- Gaudin PB et al: The pathologic spectrum of pulmonary lesions in patients with anti-neutrophil cytoplasmic autoantibodies specific for anti-proteinase 3 and anti-myeloperoxidase. Am J Clin Pathol. 1995 Jul;104(1):7-16.
DISCLOSURE: The following authors have nothing to disclose: Omar Farrukh, Jean Keddissi, Stanley Lightfoot, HOussein Youness
No Product/Research Disclosure Information