A specimen has a reduced total hemolytic complement as measured by CH50. When individual components were measured, total C3 was very reduced, but total C4 was within normal limits. How can these results be best explained?

Question

Quizplus · Accepted Answer

The reduced total C3 with normal C4 levels suggests activation of the alternative complement pathway, which can directly consume C3 without initially involving C4.

A Specimen Has a Reduced Total Hemolytic Complement as Measured