Pneumonia, Anemia, and a Positive Coombs Test

Abstract

A 13-month-old previously healthy African American male presented with a 10-day history of cough and a 4-day history of fever up to 104°F. His examination was unremarkable except for nasal congestion and clear nasal discharge. The chest radiograph was normal. The patient was not prescribed antibiotics and was discharged with a diagnosis of viral upper respiratory tract infection. Over the next 2 days, he only had low-grade fever. However, on the day of admission, he again developed fever up to 104°F accompanied by tachypnea and lethargy. A repeat chest radiograph showed opacities in the right lower lung base with pleural effusion. He was hospitalized for further care. Chest ultrasound showed anechoic regions separated by septae in the upper chest diagnosed as empyema. No surgical intervention was done. Complete blood count (CBC) on the peripheral smear at the time of admission showed a white blood cell count (WBC) of 13 000/mL, with 83% neutrophils, 12% lymphocytes, and 5% monocytes. Hemoglobin and hematocrit were 8.7 gm/ dL and 25.6%, respectively, and platelet count was 272 000/mL. Empirical treatment with ceftriaxone and linezolid was initiated. After 12 hours, the patient became afebrile with oxygen saturations of 98% on room air. However, he remained lethargic. A repeat CBC showed a WBC 19 500/mL, 63% neutrophils, 14% lymphocytes, 10% monocytes, and 8% banded neutrophils. The hemoglobin decreased to 5.5 gm/dL, and the platelet count to 45 000/ mL. A direct Coombs’ test done at this time was positive, and hematology was consulted. Subsequently, it was noted that there was a decrease in urine output. Review of the peripheral blood smear showed toxic changes along with schistocytes confirming that the infection was associated with microangiopathic hemolytic anemia. Blood urea nitrogen level was 61 mg/dL, and creatinine level was 2.7 mg/dL. Blood culture done grew penicillinresistant Streptococcus pneumoniae 19A susceptible to ceftriaxone. The patient was transfused with washed red blood cells and platelets. Because of persistent anuria and metabolic abnormalities, hemodialysis was initiated. The hematology evaluation did not reveal any underlying hemolytic condition. A repeat Coombs’ test (done within several hours of the first test and prior to transfusion of any blood products) was negative. Repeat blood cultures remained sterile. The patient was discharged after 2 weeks to complete a total of 4 weeks of antibiotic therapy. His pleural effusion resolved; however, he continues to have hypertension.