Is thyroid autoimmunity a risk factor for developing primary myelodysplastic syndrome?

Objective: Thyroid disease has been associated with leukemia and lymphoma. No previous study using clinical and laboratory data has explored whether thyroid disease and especially autoimmune thyroid disease (ATD) is associated with myelodysplastic syndrome (MDS) risk. In this case-control study, we investigated the association of ATD with MDS.
Methods: Our study included 101 cases with incident primary MDS confirmed by histology and cytogenetics, and 101 controls matched on gender and age, admitted for non-neoplastic and non-infectious diseases. All subjects were submitted to clinical, ultrasound thyroid evaluation and serum free T3, free T4, TSH, thyroglobulin, and thyroperoxidase antibodies determination.
Results: Adjusting for age, gender, and body mass index, there was statistically significant evidence that ATD is associated with increased risk of MDS (OR = 2.58, 95% CI 1.29-5.16). Interestingly, ATD starting from the remote past (more than 10 years from MDS onset) was positively associated with MDS risk (OR = 5.73. 95% CI 2.03-16.16). Mean serum levels of fT3, fT4, and thyroid antibodies were significantly higher in MDS patients and mean TSH serum levels were significantly lower in MDS patients than in controls (p < 0.05).
Conclusion: Biological plausibility and empirical evidence highlights the importance of ATD in MDS etiopathogenesis. Further studies are needed to explore underlying mechanisms associating thyroid autoimmunity with leukemogenesis.