Defining and Diagnosing cGVHD

Segment 2 focuses on foundational concepts in diagnosing cGVHD and distinguishing it from acute GVHD. Dr. DeFilipp explains that the traditional time-based distinction (acute before day 100 and chronic after) has been replaced by biologic and clinical criteria, as acute and cGVHD represent distinct disease processes rather than points along a timeline.

He reviews the broad organ involvement observed in cGVHD, emphasizing that nearly any organ system can be affected, with skin, eyes, and mouth being the most common. The segment highlights the importance of maintaining a high index of suspicion, particularly months to years post-transplant, and conducting thorough, routine assessments even when symptoms appear mild. Dr. DeFilipp stresses that early manifestations may be subtle and underrecognized by patients unless proactively addressed by clinicians.

Risk factors such as donor type, degree of HLA matching, prior GVHD episodes, and immunosuppressive exposure are discussed as key contextual elements that inform diagnostic certainty. The segment reinforces that diagnosis requires synthesis of timing, symptom pattern, transplant history, and clinical judgment, rather than reliance on a single criterion.