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

microscope A microscope () is a 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 means being invisibl ...

where

red blood cell Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...

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 medicineImmunology for Medical Students, Roderick Nairn, Matthew Helbert, Mosby, 2007 and biology that covers the medical study of immune systems in humans, animals, plants and sapient species. In such we can see there ...

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 A T cell is a type of lymphocyte. T cells are one of the important white blood cells 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 ...

s although more modern tests such as

immunohistochemistry Immunohistochemistry (IHC) is the most common application of immunostaining. It involves the process of selectively identifying antigens (proteins) in cells of a tissue section by exploiting the principle of antibodies binding specifically to a ...

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 Fetal-maternal haemorrhage is the loss of fetal blood cells into the maternal circulation. It takes place in normal pregnancies as well as when there are obstetric or trauma related complications to pregnancy. Normally the maternal circulation and ...

in case of an

Rh negative The Rh blood group system is a human blood group system. It contains proteins on the surface of red blood cells. After the ABO blood group system, it is the most likely to be involved in transfusion reactions. The Rh blood group system consist ...

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. It is often given both during and followi ...

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 objects and areas of objects that cannot 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 micr ...

. 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 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