TITLE:
Shared Autoimmunity: A Case Series of 56 Patients with Immune Thrombocytopenia (ITP) Associated with Other Autoimmune Disorders
AUTHORS:
Lizbeth-Estefanía Díaz-Polo, Núria Pujol-Moix, Blanca Jiménez, Carme Canals, Edgardo Barranco-Charris, Eduardo Muñiz-Díaz, Juan-Carlos Souto
KEYWORDS:
Shared Autoimmunity, Overlap Syndromes, Secondary Immune Thrombocytopenia, Systemic Lupus Erythematosus, Hashimoto Thyroiditis
JOURNAL NAME:
Open Access Library Journal,
Vol.3 No.8,
August
3,
2016
ABSTRACT: The association of two or more autoimmune disorders in the same individual
has been attributed to “shared autoimmunity” caused by the interaction between genetic
and environmental factors. We present the retrospective analysis of 56 patients
with Immune Thrombocytopenia (ITP) associated with other autoimmune disorders. Age,
sex, clinical manifestations, platelet count, platelet autoantibodies and therapeutic
responses were similar to those described in isolated ITP. However, we found a higher
proportion of familial forms, suggesting a greater proportion of genetics in the
etiopathogenesis of ITP associated with other autoimmune disorders. A total of 71
associated autoimmune disorders were found, the most frequent being systemic lupus
erythematosus and Hashimoto thyroiditis. Most autoimmune disorders appeared before
or after ITP but their simultaneous presentation was less frequent. Isolated laboratory
markers of additional auto-immune disorders, mainly antinuclear and antithyroid
antibodies, were found in about 20% of patients. Unlike ITP secondary to infectious
or neoplastic diseases, ITP associated with other autoimmune disorders did not show
significant differences with isolated ITP and it could appear indistinctly before,
simultaneously, or after the associated disease. These characteristics suggest the
need for a critical reconsideration of the term “secondary ITP” when ITP is associated
with other autoimmune disorders.