Diffuse Alveolar Hemorrhage Associated with Antineutrophil Cytoplasmic Antibody levels in a Pregnant Woman Taking Propylthiouracil
A 25-year-old woman in her first trimester of pregnancy was admitted to our hospital because of dyspnea and cough that developed three days prior to admission. The patient had a history of hyperthyroidism, which had developed at 16 years of age. She had been taking PTU for five years and was euthyroid. One month prior to admission PTU was resumed due to hyperthyroidism. On admission the temperature was 37.8℃, the blood pressure 120/70 mmHg, the pulse 110 beats per minute and the respiration rate 24 breaths per minute. The oxygen saturation was 96 percent while she was breathing ambient air. On physical examination, a few crackles were heard bilaterally and the thyroid gland was enlarged. Laboratory values showed a leukocyte count of 13,620/mm3, hemoglobin of 10.1 g/dL, platelet of 21,400/mm3 and a CRP of 1.27 mg/dL. Renal and liver function tests were normal. The prothrombin time was 11.2 seconds and the activated partial-thromboplastin time was 20.7 seconds. The T3 was 2.62 ng/mL (normal range, 0.79-1.49 ng/mL), free T4 0.42 ng/dL (normal range, 0.71-1.48 ng/dL) and thyroid stimulating hormone 0.004 IU/mL (normal range, 0.35-4.93 IU/mL). Urinalysis showed three to four red cells per high power field without proteinuria. A chest X-ray after abdominal protection showed bilateral heterogeneous pulmonary opacities (). The patient was diagnosed as having pneumonia and was treated with ceftriaxone and azithromycin. On the third day of hospitalization, the patient rapidly deteriorated. She was transferred to the ICU. Mechanical ventilatory support was initiated for hypoxic respiratory failure. The CT scan showed multifocal areas of ground-glass opacities and consolidation in both lung fields (). A surgical lung biopsy was considered but was not performed because of the risk of thyrotoxicosis. A bronchoscopy was performed and revealed active bleeding from segmental bronchi in the right and left lobes of the lung. The hemoglobin dropped to 7.3 g/dL and the serum p-ANCA was a strong positive and MPO-ANCA was positive with a titer of 255 AAU/mL (reference laboratory range, positive if 180 > AAU/mL; ). Tests for antinuclear antibody, anti-DNA antibody, rheumatoid factor, anti-glomerular-basement-membrane antibody, anti-proteinase 3 ANCA (PR3-ANCA), hepatitis serology and HIV were all negative. All additional biochemical testing was within normal limits. The PTU was discontinued and high dose intravenous corticosteroid therapy (methyprednisolone 125 mg every 6 hour) was started. Because of the pregnancy, methimazole was substituted for PTU. After initiation of corticosteroid therapy, the patient rapidly improved. Corticosteroid therapy was tapered slowly over four weeks, and the patient was discharged after one month. She remains in clinical remission six months later and the level of the MPO-ANCA has decreased to 159 AAU/mL.