Rouleaux Formation

Rouleaux Formation

Background Information of Rouleaux Formation

Rouleaux formation is a RBC phenomenon that is caused by an increased  concentration of plasma proteins such as fibrinogen, globulin, or paraproteins in the blood. The characteristically flat surface of the discoid RBCs provides a large surface area to make contact and stick to each other; thus, forming a coin-stacking like formation known as rouleaux formation. In particular, fibrinogen, an acute phase protein promotes the interaction of sialic acid with the surface of RBCs resulting in the formation of this rouleaux phenomenon. When this phenomenon is observed throughout the PBF slide, the medical technologist will usually suggest a blood sample to measure the Erythrocyte Sedimentation Rate (ESR). Patients that suffer from this condition, will have an enhanced ESR. This is because a rouleaux formation with a few RBCs sticking onto one another on tangent will increase their density leading to an accelerated sedimentation.

Clinical Significance

Clinical conditions that can lead to this phenomenon includes: 

• Infections
• Multiple myeloma
• Inflammatory
• Connective tissue disorders
• Cancers

Cellular Description

The hall mark of rouleaux formation is the presence of numerous RBCs stack in an almost linear coin-stack formation. These abnormal RBCs usually appear slightly bigger than the normal RBCs.