Lymphocyte Immune Globulin Health Article

Definition

Lymphocyte immune globulin is a drug used to suppress the immune system. Lymphocyte immune globulin is also known by the generic name anti-thymocyte globulin (ATG) and the brand names Atgam and Thymoglobulin. Atgam first received FDA approval in 1981 and Thymoglobulin in 1999. As of 2001, no generic preparations are available.

Purpose

Lymphocyte immune globulin is used to treat aplastic anemia and to prevent rejections during bone marrow transplantation. This drug has also been used experimentally to treat advanced non-Hodgkin's lymphomas and cutaneous T-cell lymphoma.

Description

This drug suppresses the immune system by slowing down T cells, cells critical in immunity. Without them, the immune system is essentially paralyzed. Lymphocyte immune globulin contains antibodies that attach to T cells and prevent them from working properly. This drug also decreases the number of T cells in the blood.

Lymphocyte immune globulin is made by vaccinating an animal with immature human T cells, then collecting the antibodies made against them. Atgam is made in horses and Thymoglobulin in rabbits.

Atgam is labeled for use only in kidney transplantation and aplastic anemia, and Thymoglobulin is specifically approved only for kidney transplantation. The effectiveness of either drug for treating aplastic anemia in cancer patients, however, is unknown.

Lymphocyte immune globulin is often used off-label to treat graft-versus-host disease (GVHD) after bone marrow transplantation. The drug has been beneficial for GVHD patients in some studies, but its effectiveness has not been conclusively demonstrated. In some clinical trials, it is also being used to prepare the patient's body for bone marrow transplantation. This drug produces short partial remissions of some lymphomas in published experiments.

Recommended dosage

The usual dose of Atgam in adults is 10-30 mg/kg (1 kilogram is 2.2 pounds). Doses of 5-25 mg/kg have been given to a few children. Thymoglobulin, which is about 10 times stronger, has a recommended dose of 1-1.5 mg/kg in adults. Typically these drugs are given daily or every other day for several days or weeks. They are injected into the blood over several hours, under close supervision in the hospital or clinic.