Pancytopenia with Iron Depletion and Subclinical Primary Hypothyroidism

Abstract

          Although normochromic normocytic anemia is commonly found in primary hypothyroidism both subclinical and overt, pancytopenia as in our case has been still rarely reported. She was a 24-year-old Thai patient who was referred to the hematologists because of the pancytopenia and gradual onset of fatigue for a month without fever. The physical examination revealed nothing abnormal, except for the obvious pallor. The blood tests showed Hb 5.3 g%, WBC 3,800/mm³, platelet 58,000/mm³, MCV 55.6 fL, MCH 15.8 pg, ferritin 14.4 ng/mL, serum iron 31.0 mcg/dL, TIBC 381 mcg/dL, Hb electrophoresis: Hb A₂ 2.2 %, Hb F 2.0 %,TSH 21.04 uIU/mL, FT₃ 3.0 pg/mL, FT₄ 0.6 ng/dL, ANA-positive, fine speckled cytoplasmic titer 1:80, anti-microsomal antibody 739.4 IU/mL, anti-thyroperoxidase antibody 1,168.8 IU/mL. The flow cytometry for PNH clone was not found. The diagnosis of pancytopenia with iron depletion and subclinical primary hypothyroidism was establishedand she was treated with the iron tablet without the thyroid hormone replacement. The pancytopenia was much improved within 3 months, Hb 12.8 g%, Hct 39.4 %, WBC 10,900/mm³, platelet 111,000/mm³, MCV 83.3 fL, MCH 27.0 pg. The pancytopenia in our case is presumed to be associated with both the iron deficiency anemia and the autoimmune process which leads to subclinical hypothyroidism because anemia and leukopenia completely recover after only iron therapy while theplatelet is still lowered. However the thrombocytopenia is not severe enough to be treated with the immunosuppressants.