Erythrocyte rosetting or E-rosetting is a phenomenon seen through a

microscope A microscope () is a laboratory equipment, laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic ...

where

red blood cell Red blood cells (RBCs), referred to as erythrocytes (, with -''cyte'' translated as 'cell' in modern usage) in academia and medical publishing, also known as red cells, erythroid cells, and rarely haematids, are the most common type of blood cel ...

s ''(erythrocytes)'' are arranged around a central cell to form a cluster that looks like a flower. The red blood cells surrounding the cell form the ''petal,'' while the central cell forms the ''stigma'' of the flower shape. This formation occurs due to an

immunological Immunology is a branch of biology and medicine that covers the study of immune systems in all organisms. Immunology charts, measures, and contextualizes the physiological functioning of the immune system in states of both health and disease ...

reaction between an epitope on the central cell's surface and a receptor or antibody on a red cell. The presence of E-rosetting can be used as a test for

T cell T cells (also known as T lymphocytes) are an important part of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell ...

s although more modern tests such as

immunohistochemistry Immunohistochemistry is a form of immunostaining. It involves the process of selectively identifying antigens in cells and tissue, by exploiting the principle of Antibody, antibodies binding specifically to antigens in biological tissues. Alber ...

are available. Rosetting is caused by parasites in the genus ''Plasmodium'' and is a cause of some malaria-associated symptoms.

Rosetting techniques

Three types of rosette techniques have been developed and used experimentally.

Rosette test for Rh factor

The ''Rosette test'' is performed on postpartum maternal blood to estimate the volume of fetal-maternal hemorrhage in case of an Rh negative mother and an Rh positive child. This estimate, in turn, also estimates the required amount of

Rho(D) immune globulin Rho(D) immune globulin (RhIG) is a medication used to prevent RhD isoimmunization in mothers who are RhD negative and to treat idiopathic thrombocytopenic purpura (ITP) in people who are Rh positive. RhIG is commonly referred to as 'anti-D ...

to administer.FETAL Maternal hemorrhage SCREEN (007-0155)
at The University of Texas Medical Branch at Galveston. Reviewed/Revised 6/27/10 by T. Moore, MT(ASCP)SBB In this test, a sample of maternal blood is incubated with Rho(D) immune globulin, which will bind to any fetal Rh positive

s, if present.Rosette test
at the TraQ Program of the BC Provincial Blood Coordinating Office. A program of the Provincial Health Services Authority. January 2005 Upon addition of enzyme-treated cDE indicator cells, the presence of Rh positive fetal blood causes rosetting, which can be seen by

light microscopy Microscopy is the technical field of using microscopes to view subjects too small to be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of microscopy: optical, el ...

. The test is recommended for Rh negative mothers within 72 hours of giving birth to an Rh-positive infant. In a positive test, it is recommended that a

Kleihauer–Betke test The Kleihauer–Betke ("KB") test, Kleihauer–Betke ("KB") stain, Kleihauer test or acid elution test is a blood test used to measure the amount of fetal hemoglobin transferred from a fetus to a mother's bloodstream. It is usually performed on ...

should be performed to confirm and quantify any positive rosette tests.

E-rosetting

E-rosetting is used in the identification of T cells where a T cells

CD2 CD2 (cluster of differentiation 2) is a cell adhesion molecule found on the surface of T cells and natural killer (NK) cells. It has also been called T-cell surface antigen T11/Leu-5, LFA-2, LFA-3 receptor, erythrocyte receptor and rosette re ...

surface protein is bound to a sugar based LFA-3 homologue on the surface of a sheep red blood cell. Because the LFA-3 homologue is only present on the surface of sheep red blood cells other species red blood cells can not be used in this type of rosetting.

EA-rosetting

Erythrocyte antibody rosetting (EA-rosetting), occurs when an antibody molecule that is specific for an epitope on another cell is embedded in the membrane of a red blood cell and then reacted against a cell carrying the epitope that the antibody is specific for.

EAC-rosetting

Erythrocyte antibody complement rosetting (EAC-rosetting), occurs when antibody in the presence of complement is bound to the surface of a red blood cell. The complement binds to the tail region (Fc region) of the antibody. Finally T-cells with a complement receptor are added and the T-cells bind to the complement on the antibody completing the rosette.

References

{{DEFAULTSORT:Erythrocyte Rosetting Blood tests