Birgitta Versluijs

15 Introduction 1 rally favorable. Mild cases are managed by supportive care only, severe cases generally respond well — with improvement within one day — to systemic corticosteroid treat- ment. 12,13 Diffuse Alveolar Hemorrhage (DAH) is characterized by dyspnea, fever, multi- focal infiltrates on chest X-ray, and rapid progression to respiratory failure. Hemoptysis may occur. Typical findings on Chest High Resolution CT scan includes diffuse ground glass opacities and interlobular septal thickening, resulting in a “crazy-paving” appea- rance. It is distinguished from other types of IPS by broncho-alveolar lavage (BAL), be- cause of the finding of progressively bloodier lavage fluid return. Despite treatment with corticosteroids, reported mortality rate in DAH is 48-100%, the cause of death being a result of superimposed multi-organ failure rather than respiratory failure. 12,13 The most important late onset non-infectious pulmonary complications following HCT is Bronchiolitis Obliterans Syndrome (BOS). It is defined as an obstructive lung disease, in the absence of infections and not responding to bronchodilators. BOS usually has an insidious onset, with cough, dyspnea and wheezing occurring months after HCT. Diagnostic criteria, mainly based on Pulmonary Function Tests (PFT) and radiologic abnormalities, are shown in Table 2. TABLE 2. Diagnostic criteria for Bronchiolitis Obliterans Syndrome / lung GVHD. National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in Chro- nic Graft-versus-Host Disease, 2015. 17 1. FEV1/vital capacity < 0.70 or the fifth percentile of predicted. a. Vital capacity includes FVC or slow vital capacity, whichever is greater. b. The fifth percentile of predicted is the lower limit of the 90% confidence interval. c. For pediatric or elderly patients, use the lower limits of normal, defined according to National Health and Nutrition Examination Survey III calculations 2. FEV1 < 75% of predicted with > 10% decline over less than 2 years. FEV1 should not correct to >75% of predicted with albuterol, and the absolute de- cline for the corrected values should still remain at >10% over 2 years. 3. Absence of infection in the respiratory tract, documented with investigations directed by clinical symptoms, such as chest radiographs, computed tomographic scans, or microbiologic cultures (sinus aspiration, URT viral screen, sputum culture, BAL). 4. One of the 2 supporting features of BOS: a. Evidence of air trapping by expiratory CT or small airway thickening or bronchiec- tasis by high resolution chest CT, or b. Evidence of air trapping by PFTs: residual volume > 120% of predicted or residual volume/total lung capacity elevated outside the 90% confidence interval. FVC, forced vital capacity.; URT, upper respiratory tract; BAL, broncheoalveolar lavage. * If a patient already car- ries the diagnosis of chronic GVHD by virtue of organ involvement elsewhere, then only the first 3 criteria above are necessary to document chronic GVHD lung involvement.