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Hyperhomocysteinemia in organ transplantation
G Sunder-Plassmann1, A Floth, M Födinger
1Department of Medicine III, University of Vienna, Austria. Gere.Sunder-Plassmann@akh-wien.ac.at
Insights
Elevated total homocysteine is linked to cardiovascular disease. Supplementing folic acid, vitamin B6, and B12 can normalize levels in transplant patients, though long-term benefits require further study.
Area of Science:
- Cardiovascular Science
- Nephrology
- Transplantation Medicine
Background:
- Elevated total homocysteine (tHcy) is a risk factor for cardiovascular disease (CVD) in the general population and transplant recipients.
- Hyperhomocysteinemia affects 50-60% of stable renal transplant recipients and most heart transplant recipients.
Purpose of the Study:
- To investigate the prevalence of hyperhomocysteinemia in organ transplant recipients.
- To evaluate the efficacy of vitamin therapy in normalizing tHcy levels in these patients.
Main Methods:
- Measurement of fasting and post-methionine loading plasma total homocysteine concentrations.
- Administration of folic acid, vitamin B6, and vitamin B12 to renal transplant recipients.
Main Results:
- Hyperhomocysteinemia is common in renal and heart transplant recipients.
- A combination of folic acid (5 mg/d), vitamin B6 (50 mg/d), and vitamin B12 (0.4 mg/d) normalized tHcy in nearly all renal transplant patients.
- Lower doses of folate and vitamin B12 suffice for individuals without renal failure.
Conclusions:
- Vitamin therapy effectively normalizes elevated homocysteine levels in renal transplant recipients.
- While treatment is promising for high-risk groups like transplant patients, its impact on CVD outcomes is under investigation and considered experimental.
Abstract:
An elevated total homocysteine plasma concentration is associated with an increased morbidity and mortality due to cardiovascular disease in the general population, in patients with renal failure and in recipients of kidney or heart transplants. The fasting or post-methionine loading plasma concentration of total homocysteine is elevated in 50-60% of renal transplant recipients with stable graft function and in the majority of heart transplant recipients. Fasting and post-methionine loading hyperhomocysteinemia can be normalized in virtually all renal transplant patients by a combination of folic acid (5 mg/d), vitamin B6 (50 mg/d) and vitamin B12 (0.4 mg/d). In individuals without renal failure much lower doses of folate and vitamin B12 are able to correct hyperhomocysteinemia. Currently, prospective studies are under way to clarify whether folate and vitamin therapy improves cardiovascular disease morbidity and mortality in the general population and in organ transplant recipients. While population wide screening for and treatment of hyperhomocysteinemia is generally not recommended, treatment of high risk patients, including renal failure patients and kidney and heart transplant recipients, can be considered but still represents an experimental therapy.