Brent Klinkhammer, MD, PharmD; Michael Gruchalla, MD
Background: Heparin-induced thrombocytopenia (HIT) is a drug-induced, immunoglobulin G medicated autoimmune disorder associated with several negative clinical outcomes including increased morbidity, mortality, and increased medical costs. Previous studies have shown associations between comorbid autoimmune diseases, but there is little known about associations between HIT and autoimmunity.
Purpose: To provide clinical data to suggest an association between HIT and autoimmunity.
Methods: Retrospective chart review of 59 cases with a diagnosis of HIT and 251 matched controls without a HIT diagnosis, comparing the prevalence of autoimmunity in each group.
Setting: A single, large upper Midwest health care system.
Results: Patients with a diagnosis of HIT were significantly more likely to have a comorbid autoimmune disease than those without a HIT diagnosis (55.9% vs 10.8%, P < 0.001). In disease-specific analyses, patients with a diagnosis of HIT were significantly more likely to have a diagnosis of antiphospholipid syndrome (15.3% vs 0.0%, P < 0.001), systemic lupus erythematous (8.5% vs 0.4%, P = 0.001), rheumatoid arthritis (5.1% vs 0.0%, P = 0.007), Hashimoto’s thyroiditis (13.6% vs 3.6%, P = 0.006), or nonischemic cardiomyopathy (5.1% vs 0.0%, P = 0.007). Patients diagnosed with HIT were significantly older than controls (P < 0.001).
Conclusion: This novel study gives evidence to suggest an association between HIT and autoimmune disease and suggests a need for more research into the relationship between HIT and autoimmunity. These results could alter the anticoagulation management of venous thromboembolism and acute coronary syndrome in patients with a previously identified autoimmune disease.
Acknowledgements: The authors would like to thank James Beal, PhD, Associate Professor in the Department of Family & Community Medicine at University of North Dakota School of Medicine & Health Sciences for his guidance in this research and assistance with the statistical analysis of results. They also would like to thank Sanford Health for its cooperation and assistance in data acquisition for the study.
Funding/Support: None declared.
Financial Disclosures: None declared.