Plasma cells in aspirates of goitre and overt permanent hypothyroidism following subacute thyroiditis. Preliminary report.

The occurrence of permanent overt hypothyroidism (POH) following subacute thyroiditis (SAT) was studied in 103 patients during 11-142 months (mean 52.8 months). Increased amount of plasma cells in cytological pictures of goitre aspirates was found at the time of diagnosis of SAT in 25 cases (24.3%). POH developed in 11 patients (10.7%). Eight patients with high titres of circulating thyroid antibodies demonstrated also cytological characteristics of autoimmune thyroiditis (increased amount of plasma cells inclusively) at the time of the diagnosis of SAT. Early developing POH in these patients was found. The association with HLA-Bw35 in this subgroup was not striking. In another subgroup of 3 patients POH developed after an interval of several years of euthyroidism following SAT. In such cases the autoimmune thyroiditis was not conspicuous and HLA-Bw35 was found in all 3 cases. Increased amount of plasma cells in aspirates of goitre at the time of symptomatology of SAT was observed only in one patient. It is concluded that increased amount of plasma cells (in addition to usual cytological picture of SAT) in aspirates of goitre at the time of clinical manifestation of SAT may be a warning of increased risk of development of permanent hypothyroidism following SAT. Some speculations on possible heterogeneity of subacute thyroiditis are presented.