In which condition would an autohemolysis test yield a positive result?

The autohemolysis test is designed to evaluate the stability of red blood cells (RBCs) under conditions that mimic the environment they may face in a patient's bloodstream. A positive result from this test indicates that the red blood cells are prone to premature destruction or hemolysis.

In hereditary spherocytosis (HS), the red blood cells are abnormally shaped and more fragile, which leads to increased hemolysis. This condition is characterized by a positive autohemolysis test.

In glucose-6-phosphate dehydrogenase (G6PD) deficiency, although there can be episodes of hemolysis precipitated by certain triggers, the standard autohemolysis test is typically not indicative of this deficiency since hemolysis in this case is often acute and related to oxidative stress rather than a stable defect leading to continuous hemolysis over time.

Pyruvate kinase (PK) deficiency can also cause hemolytic anemia, but the autohemolysis test may not yield a positive result consistently due to different mechanisms involved in RBC destruction compared to hereditary spherocytosis.

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by episodes of hemolysis, but the autohemolysis test is