Chapter 55: Immunopharmacology
HC is a 56-year-old man who underwent a successful lung transplant. Upon discharge he reviewed his drug regimen with the transplant team. It included cyclosporine. Which of the following most accurately describes the immunosuppressant action of cyclosporine?
(A) Activation of NK cells
(B) Blockade of tissue responses to inflammatory mediators
(C) Increased catabolism of IgG antibodies
(D) Inhibition of the gene transcription of interleukins
(E) Interference with MHC II-peptide activation of T cells
Cyclosporine inhibits calcineurin, a serine phosphatase that is needed for activation of T-cell-specific transcription factors such as NF-AT. Gene transcription of IL-2, IL-3, and interferon-γ is inhibited. The answer is D.
In addition to cyclosporine HC received two other drugs. Can you identify the second drug? It suppresses cellular immunity, inhibits prostaglandin and leukotriene synthesis, and increases the catabolism of IgG antibodies.
(D) Mycophenolate mofetil
The corticosteroid prednisone is used extensively as an immunosuppressant in autoimmune diseases and organ transplantation. Glucocorticoids have multiple actions, including those described. The answer is E.
A 30-year-old woman has one living child, age 6 years. Her child and her husband are Rh positive and she is Rho(D) and Du negative. She is now in her ninth month of pregnancy and is in the labor room having frequent contractions. Her Rh antibody test taken earlier in the pregnancy was negative. What immunotherapy is appropriate for this patient?
(D) Rho(D) immune globulin
Rho(D) immune globulin contains antibodies against Rho(D) antigens. If an injection of Rho(D) antibody is administered to the Rh-negative mother within 24–72 h after the birth of an Rh-positive infant, the mother’s own antibody response to the foreign Rho(D)-positive cells is suppressed because the infant’s red cells are cleared from circulation before the mother can generate a B-cell response against Rho(D). Therefore, she has no memory B cells that can activate upon subsequent pregnancies with an Rho(D)-positive fetus. The answer is D.