Immuno q from UW

[MudPhud20XX]

Could we discuss this q?

A 32 yr old woman who recieved minimal prenatal care during her pregnancy gives birth to an infant with jaundice, hepatomegaly, and generalized edema. Lab studies show a hemoglobin level of 6 g/dL and peripheral blood smear shows many nucleated erythrocytes. The infant dies soon after birth, and on autopsy areas of extramedullary hematopoiesis are found in many tissues. Which of the following is the most likely cause of this pt's condition?

A. Abnormal hemoglobin polymeriziation
B. Decreased bilirubin conjugation
C. Erythrocyte opsonization by maternal antibodies
D. Glucose 6 phosphate dehydrogenase def
E. Impaired inhibition of complement activation
F. Red blood cell lysis by fetal antibodies

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[dfib slim]

Could we discuss this q?

A 32 yr old woman who recieved minimal prenatal care during her pregnancy gives birth to an infant with jaundice, hepatomegaly, and generalized edema. Lab studies show a hemoglobin level of 6 g/dL and peripheral blood smear shows many nucleated erythrocytes. The infant dies soon after birth, and on autopsy areas of extramedullary hematopoiesis are found in many tissues. Which of the following is the most likely cause of this pt's condition?

A. Abnormal hemoglobin polymeriziation
B. Decreased bilirubin conjugation
C. Erythrocyte opsonization by maternal antibodies
D. Glucose 6 phosphate dehydrogenase def
E. Impaired inhibition of complement activation
F. Red blood cell lysis by fetal antibodies

C
Hydrops fetalis from Rh incompatibility

 

[Silverish]

I agree with @dfib slim C.
The child has a high turnover rate of RBC's. You know this because he has jaundice (too many cells are being broken down), and has a high reticulocyte count (too many cells are being made at once - pushing early RBC's into the vasculature). The extramedullary hematopoiesis is just an additional factor to this diagnosis.
So, with that said, you know this is a type of hemolytic anemia in a newborn.
A. Sickle cell isn't observed well in newborns as they have HbF
B. Criggler Najjar isn't a bad answer here, but happens after birth (not at birth). Even if it did, it has nothing to do with prenatal care as Hydrops fetalis would.
D. G6PD def. will only show inc. unconjugated bilirubin after an oxidizing stress, usually later in life.
E. Fetus doesn't start making antibodies until its born. So F doesn't make sense here.