INTRODUCTION: The syndrome of pulmonary infiltrates and eosinophilia (P.I.E.) includes a wide spectrum of clinical disorders with pulmonary infiltrates and peripheral eosinophilia. These include parasitic infections, acute and chronic eosinophilic pneumonias, drug reactions, Churg-Strauss syndrome, collagen vascular diseases and malignancies. We describe an unusual case of pulmonary infiltrates with eosinophilia mimicking pulmonary tuberculosis in an immigrant patient from a tuberculosis-endemic country.
CASE PRESENTATION: A 47-year-old Moroccan woman presented with dry cough, exertional dyspnea, fatigue and significant weight loss over 2 months. She denied fever, night sweats and hemoptysis. Past history was significant for incompletely treated pulmonary tuberculosis (PTB) and sinusitis. No sick contacts or recent travel was reported. She had emigrated from Morocco five years prior and had revisited two years prior to presentation. Medications included Albuterol inhaler and Cetrizine. On examination, she was afebrile, tachycardic and hypoxic, and had bronchial breath sounds at bilateral lower lung zones. Initial leukocyte count was 14,000/mm3, and chest X-ray revealed bilateral alveolar infiltrates with pleural effusions, confirmed by CT (computed tomography) chest. Empiric four drug treatment for PTB was initiated. The patient subsequently developed cardiac tamponade. Pericardial and right pleural effusions were drained. Both revealed 75% eosinophilia, as did peripheral blood. Sputum smears were negative for acid fast bacilli, so PTB drugs were discontinued. Bronchoalveolar lavage (BAL) revealed 26% eosinophils with negative cultures and no parasites. Serology and microscopic examination for various parasitic infections was negative. Rheumatologic work-up did not reveal any connective tissue diseases. A bone marrow biopsy subsequently showed marked eosinophilia with mature eosinophils and negative FIP1L1-PDGFRA (Platelet Derived Growth Factor Receptor Alpha) mutation, suggesting idiopathic hypereosinophilic syndrome (IHES). Our patient received oral steroids and had complete clinical and radiographic recovery within 3 weeks.
DISCUSSION: IHES, first described in 1968, is a group of leuko-proliferative disorders with sustained overproduction of mature eosinophils resulting in organ damage. Defining features (1) include sustained blood eosinophilia >1,500/mm3 for over 6 months, absence of other apparent etiologies for eosinophilia (parasitic infections, allergic diseases, drugs, eosinophilic pneumonia), and presence of signs and symptoms of organ involvement. Eosinophils in peripheral blood, tissues and bone marrow are usually mature. Pulmonary and cardiac manifestations are seen in up to 50-60% patients and can mimic multiple diseases. Frequency of pericardial involvement is less than 10%. Only two cases of IHES with cardiac tamponade have been reported till date. Corticosteroids are the first-line agents for patients with organ involvement. Recently, fusion of FIP1L1 and PDGFRA genes has been shown to be a therapeutic target for imatinib mesylate in IHES (2). A large randomized trial in 2008 also showed that use of mepolizumab, an anti-interleukin-5 monoclonal antibody, resulted in corticosteroid-sparing for IHES patients negative for FIP1L1-PDGFRA (3).
CONCLUSIONS: Our case highlights significant points. Firstly, IHES can mimic multiple pulmonary diseases, and therefore, infections must always be ruled out prior to establishing a diagnosis and initiating steroids. Secondly, alternative causes for eosinophilia must be looked for, especially parasitic infections in patients from endemic areas. Thirdly, pericardial involvement in IHES is rare, and our patient is the third ever reported case of IHES developing cardiac tamponade.
Reference #1 The Hypereosinophilic Syndrome: Analysis of fourteen cases with review of literature. Chusid MJ, Dale DC, West BC, Wolff SM. Medicine (Baltimore).1975 Jan;54(1):1-27.
Reference #2 Efficacy of imatinib mesylate in the treatment of idiopathic hypereosinophilic syndrome. Cortes J, Ault P, Koller C, Thomas D, Ferrajoli A. Blood 2003;101:4714-6.
Reference #3 Treatment of patients with the hypereosinophilic syndrome with mepolizumab. Rothenberg ME et al. N Engl J Med 2008;358(12):1215-28.
DISCLOSURE: The following authors have nothing to disclose: Shweta Gupta, Arshad Wani
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