Findings from a new study presented at the 57th Annual Meeting of the American College of Hematology may offer fresh insight into why some patients with sickle cell disease (SCD) develop chronic pain and suggests a novel biomarker for the assessment of patients with the condition. The research was conducted at the Medical College of Georgia at Augusta University, where previous work had demonstrated that patients with SCD had elevated pain sensitivity. In this study patients with SCD were classified as suffering from chronic pain, or non-chronic pain, and were compared to a control group of African Americans who did not have SCD.
The SCD patient cohort with chronic pain (defined as >50 days of diary-reported pain) were found to be older, heavier users of opioids, and to present with multiple comorbidities that are atypical to SCD diagnosis. Patients with SCD frequently experience episodes of vaso-occlusive crisis (VOE) that require acute pain therapy, and the authors hypothesize that as younger patients suffering from VOE age, their nociceptive pain can evolve into neuropathic and centralized pain, creating the framework for chronic pain. Additionally, the research found that this group showed evidence of elevated levels of tryptase, which could be an indicator of increased mast cell elevation. Mast cell activation factors into sickle pathobiology and pain by promoting neurogenic inflammation and nociceptor activation through the release of substance P, a neuropeptide. A news story, co-authored by PAINWeek faculty member Forest Tennant, MD, DrPH, may be read here.