Birgitta Versluijs

14 1 Pulmonary complications of HCT Idiopathic Pneumonia Syndrome (IPS), is regarded an early onset non-infectious lung complication occurring within the first 100 days after HCT. IPS usually has an acute onset of respiratory insufficiency and hypoxia. IPS has an overall incidence of 2-12% after HCT and a poor prognosis, with mortality rates of 50-80% within the first month of diagnosis. 15 It is defined by evidence of alveolar disease in the absence of infection or cardiac disease/ fluid overload otherwise explaining pulmonary symptoms. 16 Diagnostic criteria are shown in Table 1. IPS by definition also includes Peri Engraftment Respiratory Distress Syndrome (PERDS) and Diffuse Alveolar Hemorrhage, clinical entities used in daily practice. PERDS occurs typically within 5 days of engraftment, and is the pulmonary manifestation of a diffuse systemic capillary leak disorder known as engraftment syndrome (ES). In its fulminant presentation, patients may have fever in the absence of infection, erythrodermatous rash > 25% of the body, diffuse pulmonary infiltrates causing dyspnea and hypoxia, and rapid weight gain caused by fluid retention. The prognosis of engraftment syndrome is gene- TABLE 1. Definitions of Idiopathic Pneumonia Syndrome (AmericanThoracic Society 2010) 16 I. Evidence of widespread alveolar injury: a. Multilobar infiltrates on routine chest radiographs or computed tomography b. Symptoms and signs of pneumonia (cough, dyspnea, tachypnea, rales) c. Evidence of abnormal pulmonary physiology 1. Increased alveolar to arterial oxygen difference 2. New or increased restrictive pulmonary function test abnormality II. Absence of active lower respiratory tract infection based upon: a. Bronchoalveolar lavage negative for significant bacterial pathogens, including acid-fast bacilli, Nocardia, and Legionella species b. Bronchoalveolar lavage negative for pathogenic nonbacterial microorganisms: 1. Routine culture for viruses and fungi 2. Shell vial culture for CMV and respiratory RSV 3. Cytology for CMV inclusions, fungi, and Pneumocystis jirovecii 4. Direct fluorescence staining with antibodies against CMV, RSV, HSV, VZV, influenzavirus, parainfluenzavirus, adenovirus, and other organisms c. Other organisms/tests to also consider: 1. Polymerase chain reaction for human metapneumovirus, rhinovirus, coronavirus and HHV6 2. Polymerase chain reaction for Chlamydia, Mycoplasma, and Aspergillus 3. Serum galactomannan ELISA for Aspergillus species d. Transbronchial biopsy if condition of the patient permits III. Absence of cardiac dysfunction, acute renal failure, or iatrogenic fluid overload as etiology for pulmonary dysfunction