Case 156

1. Presented by Abi Norwood, M.D.  and reviewed by Herleen Rai, MD

A child arrives at the emergency department (ED) presenting with fever, fatigue, and dark brown discolored urine. The child has no significant past medical problems.

A history and physical reveals the child had a recent upper respiratory infection. On exam, the child is currently febrile (with a Tmax 102.1°F), lethargic, and exhibiting diffuse jaundice. Initial laboratory results indicate severe anemia (hemoglobin 5.7 g/dL) and signs of hemolysis (total bilirubin: 2.5 mg/dL, lactate dehydrogenase: 2,255 U/L, haptoglobin: <3 mg/dL). An expedited blood bank workup is performed and includes a Donath-Landsteiner test, the results of which are shown below.

Donath-Landsteiner test:

30 minutes 0°C,

60 minutes 37°C​

90 minutes 0°C​

90 minutes 37°C​

A1​A2​A3​B1​B2​B3​C1​C2​C3​Interpretation ​
++++​+++​0​++​+​0​++​+​0​Positive
Question:  Given the clinical presentation, what is most likely direct antiglobulin test (DAT) results for this patient?
 

Poly Specific
(anti-IgG, anti-C3)

Anti-IgG

Anti-C3

A.

+++

B.

++

-

C.

+-

+

D.--

-