An Adult with Aplastic Crisis induced by Human Parvovirus B19 as an Initial Presentation of Hereditary Spherocytosis
A 34-year-old female was admitted to the hospital with the chief complaint of presyncope, which had developed a few hours previously. She also complained of febrile sensation and myalgia which had begun 4 days prior to admission. She had no allergies or past medical history, and her family history was unremarkable. The physical examination revealed a blood pressure of 90/60 mmHg, a pulse rate of 96 beats per minute, a temperature of 37.8℃, and a respiration rate of 18 times per minute. Her skin and conjunctivae were pale, and sclera was yellowish. No evidence of cervical lymphadenopathy or abnormal findings upon chest examination was found. The low margin of the spleen was palpable at 5 cm from the costal margin. The initial complete blood counts were as follows: hemoglobin (Hb) 3.0 g/dL, hematocrit (Hct) 8.4%, MCV 81.7 fl, MCHC 36%, white blood cell (WBC) count 3,160/mm3 (segmented neutrophil 66%, lymphocytes 30.5%, monocytes 1.5%), platelets count 163,000/mm3, and reticulocytes 0.2%. Liver function tests showed an aspartate aminotransferase 81 IU/L, alanine aminotransferase 52 IU/L, total bilirubin 5.2 mg/dL with indirect bilirubin of 3.5 mg/dL, and lactate dehydrogenase 763 IU/L. Serum iron, total iron binding capacity, and ferritin level were within normal ranges, and haptoglobin had been decreased to 38.0 mg/dL. The peripheral blood smear revealed spherocytosis with reticulocytopenia and pancytopenia (). The direct antiglobulin (Coombs) test was negative, and osmotic fragility of patient's red cells was increased. Bone marrow aspirate smears showed a few giant pronormoblasts with deep blue cytoplasm, pseudopods, and poorly demarcated intranuclear inclusions (). These results indicate that the diagnostic hypothesis was an aplastic crisis induced by HPV B19 infection in a patient with underlying HS. Using the patient's peripheral blood and bone marrow aspirate, we performed polymerase chain reaction (PCR) for the detection of HPV B19 DNA. The PCR of the patient's materials resulted in an amplification of the 496 base pair (bp) band, which was confirmed by the nested PCR, where a 232 bp band was amplified (). The patient was subsequently given eight units of packed red blood cells. During the course of admission, the WBC count decreased to 1,170/mm3 on the 2nd day and platelet count fell to 93,000/mm3 on the 4th day. We requested a serologic test for anti-HPV B19 IgM and IgG antibodies on the 10th day of hospitalization. Hematologic recovery began 12 days after admission. At discharge on the 15th day, the Hb was 8.4 g/dL, Hct 24.3%, WBC count 5,840/mm3, platelet count 233,000/mm3, and reticulocyte 5.1%. HPV B19 serology was pending at the time of discharge. One week later, the patient's Hb and Hct rose to 10.0 g/dL and 30%, with a reticulocyte count of 10%. Tests for anti-HPV B19 IgM and IgG antibodies were positive.