INTRODUCTION: Diffuse alveolar hemorrhage (DAH) is associated with a variety of clinical disorders, but is very rarely associated with post-infectious glomerulonephritis (PIGN). In fact, there have only been three cases previously reported in the literature. We describe a patient who was found to have DAH in the setting of biopsy-proven PIGN and discuss his course in comparison to prior cases.
CASE PRESENTATION: A 37 year old African American man with a history of gunshot wound presented to the hospital for respiratory distress. He reported a dry cough and worsening shortness of breath over the past several days. He denied sputum production, fever, sore throat, or urinary complaints. Symptoms began following a one week history of vague gastrointestinal symptoms that spontaneously resolved. On examination, patient was afebrile with blood pressure of 160/110 mmHg, heart rate of 96 beats per minute, respiratory rate of 24 breaths per minute, and oxygen saturation 93% on room air. Pertinent findings included absence of JVD, diffuse rales and ronchi, normal S1 and S2 without murmurs or gallops, and absence of peripheral edema. Serum creatinine was 1.1 mg/dL and hemoglobin 9.5 g/dL. Chest radiograph revealed diffuse bilateral infiltrates; computed tomography of chest revealed dense multifocal infiltrates of unclear etiology. Urine analysis revealed large proteinuria and hematuria. The patient was empirically treated for pneumonia; however, his pulmonary status worsened, as did his renal function. A pulmonary-renal syndrome was considered; anti-glomerular basement membrane, antinuclear, antineutrophil cytoplasmic, and anti-ds DNA antibodies were negative. Cryoglobulin and HIV testing was negative. His antistreptolysin antibody titer was extremely elevated at 997 IU/mL, with low C3 and normal C4 levels. Bronchoscopy with serial bronchoalveolar lavages produced increasing red blood cell counts and hemosiderin-laden macrophages. A renal biopsy revealed granular deposition in mesangium and glomerular basement membrane that stained positive for C3 by immunofluorescence. Light microscopy revealed margination of neutrophils in capillary lumina, also consistent with post-infectious glomerulonephritis. The patient was treated with pulse dosing of high dose intravenous methylprednisolone. His respiratory status and hypoxia improved, as did his renal function.
DISCUSSION: DAH has previously been associated with an array of clinical diagnoses, some of which concomitantly affect the kidney, specifically acute nephritides. PIGN's association with DAH is extremely rare with only 3 cases reported in the medical literature and the evidence for a treatment strategy is subsequently nonexistent. PIGN characteristically develops ten to fourteen days after pharyngitis or skin infection with group A beta-hemolytic streptococcus. PIGN clinically manifests as gross hematuria, oliguric renal failure, edema, and hypertension. Laboratory studies usually reveal an elevated antistreptolysin antibody titer and a low C3 level along with a normal C4 level. The clinical course for PIGN is usually very mild, as was the case for our patient. Proposed pathogenic mechanisms for the development of DAH with PIGN are not well founded, but include immune complex deposition on broncho-alveolar epithelium and capillary basement membrane. An acute inflammatory reaction may disrupt the alveolar bed and capillary basement membrane, and lead to capillaritis and DAH. In the few cases reported, high dose intravenous pulse steroid therapy was used with consistent improvement in DAH and intermittent resolution of renal dysfunction; one of the previously reported cases did progress to renal failure.
CONCLUSIONS: Diffuse alveolar hemorrhage is very rarely associated with post-infectious glomerulonephritis; however, a clinician must be aware of this possibility once the appropriate constellation of symptoms exists. An accurate diagnosis must be made for the purposes of treatment and prognosis.
Reference #1 Sung HY, Lim CH, Shin MJ, Kim BS, Kim YO, Song HC, Kim SY, Choi EJ, Chang YS, Bang BK. A case of post-streptococcal glomerulonephritis with diffuse alveolar hemorrhage. J Korean Med Sci. 2007;22:1074-1078
DISCLOSURE: The following authors have nothing to disclose: Thomas Martin, Kenneth Berger
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