Which leukocyte abnormality is suggested by the presence of roulaeu formation in a blood smear?

The presence of rouleaux formation in a blood smear is strongly associated with conditions characterized by increased levels of certain proteins in the blood, particularly immunoglobulins. Multiple myeloma, a malignancy of plasma cells, often leads to the overproduction of monoclonal antibodies. These proteins can cause red blood cells to stack together, resembling a stack of coins, which is what rouleaux formation looks like under a microscope.

In the context of multiple myeloma, the high concentration of immunoglobulins alters the plasma viscosity and enables these stacking formations to appear. This phenomenon is utilized diagnostically to suggest underlying conditions like multiple myeloma, especially when viewed alongside clinical symptoms and other laboratory findings.

While other conditions can influence red blood cell morphology, they do not specifically cause rouleaux formation in the same characteristic way. For example, infection might lead to an increase in white blood cells, iron deficiency anemia is more about red blood cell size and count rather than stacking phenomena, and dehydration affects plasma volume rather than the specific immunoglobulin dynamics involved in rouleaux formation.