Paroxysmal Nocturnal Hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hemolytic anemia characterized by hemolysis, thrombotic events, and bone marrow failure resulting from deficiency of glycosylphosphatidylinositol-linked proteins due to inactivation of X-linked PIGA gene. As both hemolysis and thrombosis are seen in clinical presentation, diagnosis is challenging and an index of suspicion is essential for improved patient management and prognosis. In this chapter, a clinical case scenario is presented followed by a step-by-step evidence-based approach to utilize specialized and advanced tests to unravel final diagnosis of PNH. A comprehensive description of pathophysiology of disease, causes of thrombosis at unusual sites, blood cells most suitable for analysis for PNH, differentiation of PNH from other causes of DAT negative hemolytic anemia, selection of patients for PNH screening and reason of esophageal spasm, priapism, and pulmonary hypertension are discussed in question–answer format. Salient points are summarized for quick revision. To gain expertise in this topic and enhance your diagnostic skills for effective planning of management, read this chapter on paroxysmal nocturnal hemoglobinuria.