• A 43-year-old woman presents with a two-to-three month history of nervousness, increased sweating, decreased tolerance to heat, palpitations, fatigue, weight loss with increased appetite, and increased bowel movement frequency. She also has puffiness around her eyes, and she has noted episodes of double vision, also of similar 2-3 months duration. She is otherwise healthy, takes no medications, and leads an active working life. This is her first episode of hyperthyroidism.

• Palpation of her neck reveals a diffusely enlarged thyroid gland, representing a goiter of 70-80 g. She has a regular pulse of 105 beats/min and typical but minimal eye signs.

• Serum levels: triiodothyronine 354 ng/dL (ref. range 52-160), thyroxine 13.9 µg/dL (ref. range 5.5-12.3), TSH <0.05 µU/mL (ref. range 0.05-5.0), and free thyroxine 2.0 ng/mL (ref. range 0.7-1.8).

• 1. What is the cause of the patient's symptoms? What kind of hypersensitivity is involved?

• 2. What are the etiology and mechanism of Graves disease?

• 3. What consequences does this disease have histopathologically in the thyroid gland?

• 4. What is the significance of the laboratory values?

• A 24-year-old woman presents with "swelling" in her neck. Upon careful questioning, she reports being "tired and cold all the time," and it is determined that these symptoms developed insidiously over a period of 4-5 years. Physical examination reveals a diffusely enlarged thyroid gland. Laboratory tests reveal thyroid hypofunction and high serum titres of antithyroid (antimicrosomal and antithyroglobulin) antibodies.

• 1. What is the nature of the pathologic process occurring in this patient's thyroid gland? What is the likely etiology of this pathology? Contrast with Case 1A.

• 2. What is the likely outcome of this case? with surgery? without surgery?

• J. W., a 20-year-old woman, presented with complaints of fever for two weeks, pleuritic chest pain, and intermittent joint pain in her hands, feet, and knees. On examination, she was free of skin lesions. She had a pleural friction rub, a slightly swollen tender right knee, and enlarged axillary, cervical, and inguinal lymph nodes. A chest film showed a small right pleural effusion; joint films were normal except for a small amount of soft tissue swelling in the right knee.

• Hemoglobin was 10 g/dL, and urinalysis revealed 4+ proteinuria with white cells, red cells, and red-cell casts in the urine sediment. A VDRL test was positive. A test for antitreponemal antibodies, however, was negative.

• The blood urea nitrogen (BUN) and creatinine were slightly elevated, and moderate hypoalbuminemia and hypergammaglobulinemia were present.

• An ANA test was positive at a titer of 1:2560 and was reported as showing a speckled pattern. A dsDNA antibody determination by the Crithidia luciliae assay was positive at 1:320, and an extractable nuclear antigen (ENA) antibody determination was reported as: RNP (U1-RNP) and Sm antibody present. A C4 level was <10 mg/dL (reference range: 12-45 mg/dL) and a C3 level was <40 mg/dL (reference range: 88-192 mg/dL). The patient was treated with steroids, 60 mg/day of prednisone.

• After four weeks, the urine protein was 2+, the sediment had cleared, and the BUN and serum creatinine had returned toward normal.