CAMLPR Competency Practice Test 2026 – Complete Exam Prep

Membrane skeleton defects in red blood cells cause loss of surface area and formation of spherocytes, which are less deformable and prone to splenic sequestration, producing a characteristic hemolysis pattern.

Here, the smear shows spherocytes and the osmotic fragility test is positive, both classic for hereditary spherocytosis. The direct antiglobulin test is negative, which argues against autoimmune hemolytic anemia that would typically have a positive DAT. The elevated unconjugated bilirubin and LDH, along with a retic count of 10%, indicate ongoing hemolysis with the bone marrow responding. The MCHC is elevated and the MCV is normal, which fits the dehydrated-spherocyte picture more than other RBC disorders. Taken together, these findings point to hereditary spherocytosis.

Other conditions don’t fit as well: autoimmune hemolysis would usually show a positive DAT; sideroblastic anemia and thalassemia trait typically present with microcytosis and different smear features rather than spherocytes with high osmotic fragility.