CAMLPR Evaluation and Interpretation Competency Practice Test 2026 - Free Practice Questions and Study Guide

The main idea is recognizing a nonimmune, membrane–defect–driven hemolysis. Echinocytes (burr cells) on a smear reflect red cell membrane instability often due to low ATP within the cell. Pyruvate kinase deficiency is a glycolytic enzyme defect that lowers ATP in red cells, causing membrane changes like burr cells and a chronic hemolytic picture. Because the hemolysis is not immune, the direct antiglobulin test is negative. The supravital dark inclusions on the membrane can be seen with membrane abnormalities of red cells, which fits this scenario of a structural/energetic defect rather than an immune process.

Other options don’t fit as well: a immune-mediated process like cold agglutinin disease would typically have a positive DAT; sideroblastic anemia doesn’t characteristically produce burr cells or these membrane inclusions; and G6PD deficiency often shows Heinz bodies (hidden in supravital stains) and bite cells, with a different smear pattern, rather than the prominent echinocytes described here.