Diagnostic Criteria and Genetic Testing in HLH Diagnosis

The chapter delves into the significance of diagnostic criteria in guiding the diagnostic process for HLH, emphasizing the role of genetic testing, functional assays, and biomarker testing. It discusses the evolution of understanding genetic mutations related to HLH and the need for comprehensive testing to rule out known genetic causes. The chapter also highlights the importance of differentiating HLH from other conditions that mimic its presentation, including discussions on secondary HLH causes and the challenges of diagnosing in patients with overlapping physiologies.