Immunosuppressive Therapy in Kidney Transplantation

Introduction to Immunosuppressants

Immunosuppressants, such as mycophenolic acid (Myfortic), are used to prevent organ rejection in kidney transplant recipients, in combination with cyclosporine and corticosteroids, with an enteric-coated formulation that delays MPA release until the small intestine 1
The American Society of Transplantation recommends mycophenolate as a first-line antiproliferative agent in kidney transplant recipients, which prevents organ rejection by inhibiting lymphocyte proliferation through selective blockade of purine synthesis 2, 3

Calcineurin inhibitors, such as cyclosporine and tacrolimus, bind to cytoplasmic receptors and inactivate calcineurin, preventing IL-2 gene transcription and T-cell proliferation, with tacrolimus showing better long-term graft and patient survival than cyclosporine 1
Antimetabolites, such as mycophenolate mofetil, inhibit inosine monophosphate dehydrogenase (IMPDH), reducing purine synthesis and lymphocyte proliferation, and have replaced azathioprine as the most commonly used antimetabolite 1
mTOR inhibitors, such as sirolimus, inhibit mammalian target of rapamycin (mTOR), blocking cytokine-driven T-cell proliferation and activation, and are used as an alternative to CNIs in patients with renal dysfunction 4
TNF-α inhibitors block interaction of TNF-α with its receptors, inhibiting proinflammatory cytokines (IL-1, IL-6) and modulating immune effector activity, and are particularly effective for immune-related colitis and inflammatory arthritis 5
IL-2 receptor antagonists, such as basiliximab, bind to CD25 on activated T lymphocytes, selectively inhibiting their proliferation, and are used as induction therapy in organ transplantation 1
Polyclonal antibodies, such as antithymocyte globulin, are heterologous preparations of rabbit- or equine-derived antibodies against human T cells, and are used as induction therapy in transplantation and treatment of steroid-resistant rejection 1, 6

The American College of Cardiology recommends losartan, an angiotensin II receptor blocker (ARB), to treat hypertension in transplant recipients, with typical starting doses ranging from 25-50 mg 2
The American Diabetes Association recommends glipizide, a sulfonylurea, to stimulate insulin secretion from pancreatic beta cells and treat type 2 diabetes in transplant recipients 2
The American Urological Association recommends tamsulosin, an alpha-1 blocker, to relax smooth muscle in the prostate and bladder neck and treat benign prostatic hyperplasia (BPH) symptoms in transplant recipients, with a typical dose of 0.4 mg once daily 2
Regular monitoring of renal function, blood glucose, electrolytes, and acid-base status is necessary due to the metabolic effects of immunosuppressants and the underlying kidney disease, as recommended by the National Kidney Foundation 2
Patients on immunosuppressive regimens should be monitored for signs of opportunistic infections, as recommended by the Infectious Diseases Society of America 2
Cardiovascular risk factors should be managed in transplant recipients, including diabetes, hypertension, and hyperlipidemia, as recommended by the American Heart Association 2

Complete blood count with differential, renal and hepatic function tests, and therapeutic drug monitoring for CNIs and mTOR inhibitors are essential for monitoring patients on immunosuppressive therapy 6
Prophylaxis for Pneumocystis jiroveci pneumonia should be considered for patients on intensive immunosuppression, and screening for latent tuberculosis prior to initiating therapy is recommended, according to the American Thoracic Society 6
Monitoring for viral infections, such as CMV, BK virus, and JC virus, is also important 7
Gastrointestinal effects, such as diarrhea, nausea, vomiting, and abdominal pain, are common adverse effects (up to 35% of patients) 3, 7
Hematologic effects, including bone marrow suppression leading to leukopenia, anemia, and thrombocytopenia, require regular complete blood count monitoring 7
Increased infection risk, including opportunistic infections and viral infections, particularly CMV, necessitates careful monitoring 7
Pregnancy risks, including increased risk of miscarriage (49%) and birth defects (23%), are associated with MMF use, prompting an FDA black box warning 8
Important drug interactions include decreased MMF levels with antacids containing magnesium/aluminum, cholestyramine, and rifampin, and increased toxicity with other immunosuppressants 9

The American Society of Transplantation recommends MMF in combination with calcineurin inhibitors (cyclosporine or tacrolimus) and corticosteroids for preventing rejection in kidney, heart, and liver transplants 3
The National Comprehensive Cancer Network recommends MMF for the management of steroid-refractory immune-related adverse events from cancer immunotherapy 5
MMF has demonstrated effectiveness in preventing acute rejection in organ transplantation, allowing reduction of calcineurin inhibitor doses to improve renal function, and treating steroid-refractory graft-versus-host disease 1, 10