IL6 and thyroiditis: Serum antibodies specific to syphilis, neurotrophic viruses, human immunodeficiency virus, and thyroid and autoimmune diseases, including interleukin-6 (IL-6), IgG4, antinuclear, anti-Sm, anti-mitochondria M2, anti-SS-A/SS-B, anti-Jo-1, anti-Scl-70, anti-acetylcholine receptor, myeloperoxidase-, and proteinase 3-anti-neutrophil cytoplasmic antibodies were all normal.