In which condition are "bite cells" commonly observed?

Bite cells, also known as degmacytes, are commonly associated with G6PD deficiency, a genetic condition that affects the enzyme glucose-6-phosphate dehydrogenase. This deficiency makes red blood cells particularly vulnerable to oxidative stress. When these cells are exposed to oxidizing agents, such as certain medications, infections, or certain foods like fava beans, they can sustain damage.

The oxidative stress leads to the formation of Heinz bodies, which are aggregates of denatured hemoglobin. The spleen recognizes these damaged red blood cells and starts removing the Heinz bodies. As portions of the cell membrane are removed during this process, it results in the characteristic "bite" appearance of the cells. Therefore, the presence of bite cells serves as an important diagnostic clue for G6PD deficiency and reflects the ongoing hemolytic process in this condition.

In contrast, the other conditions listed do not typically lead to the formation of bite cells in the same way. Rh null trait primarily affects hemolytic anemia due to Rh incompatibility, chronic granulomatous disease involves issues with phagocyte function and susceptibility to certain infections, and PK deficiency is more associated with different morphological changes in red blood cells rather than bite cells. Understanding these associations