Endocrine Abstracts

Extracellular matrix protein 1 (ECM1) is an 85 kDa glycoprotein that plays an important role in skin physiology, angiogenesis, tumor progression and malignancies. However, the function of ECM-1 in regulation of the immune responses has not been identified. Recent studies showed ECM-1 deficiency lowers the capacity of T helper 2 (Th2) cells to emigrate from draining lymph nodes to an inflamatory site. Lipoid proteinosis (LiP) and Licken Sclerosus (LS) are immunogenetic counterparts; both target ECM-1 and sharing similar skin pathology. LiP is associated with loss of function mutations in the ECM-1 gene which located on 1q21. Mutation leads to abnormal degradation of glycolipids or sphingolipids, increased production of basal membrane collagens and decreased production of fibrous collagens. It is characterized by hyaline like material deposition in the skin, oral cavity; causing hoarseness, chicken-pox like scars, eyelid papules. Nevetheless, LS is caused by the development of humoral autoimmunity to ECM-1 which is characterized by small papules and pruritus. Attributed to the underlying pathogenic mechanism, LS were reported to have an increased incidence of autoimmune diseases especially Graves’ disease (GD). Hyperthyroidism; most common feature of the GD, is caused by autoantibodies to the thyrotropin receptor (TSH-R). The derangement of immune function leading to pathalogic autoantibody production is complicated. Disturbing the T cell response, in particular disrupting the anti inflamatory regulatory T cells can result hyperthyroidism by increasing production of Trab, demonstrating GD is primarily a Th2 type autoimmune disease. Our case, a 20-year-old female presented with palpitation, fatigue and a slowly-enlarging mass in her front neck. Her weight was 53 kg, height was 155 cm. Thyroid function tests were consistent with hyperthyroidism. Thyroid Peroxidase Antibody (TPOAb) was negative. We could not measure Tyroglobulin Antibody (TgAb) due to economic issues. Her thyroid ultrasound and sintigraphy was compatible with GD and methimazole treatment was started. In her medical history, she had undergone a epiglottis biopsy because of hoarseness which had revealed lipoid proteinosis, 2 years ago. She had acneiform scars and eyelid papules which is charesteristic for the disease. She was on retinoic acide treatment for skin lessions. Unlike the current literature, our case demonstrated an Th2 type autoimmune thyroid disease with an underlying lipoid proteinosis disorder which is supposed to have decreased capability of Th2 response in the ECM-I deficiency. As it is a rare condition, further studies is needed to understand the immunregulatory role of ECM-1 and also immune mechanism of the GD.