Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0024312 (lymphopenia)
 4,859 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

More immunosuppressive drugs than ever have recently graduated from the laboratory to extensive clinical trials of their safety and efficacy in patients undergoing transplantation. Although none of these drugs is perfect, they control different forms of rejection in stringent animal models more effectively than other immunosuppressants; yet these novel molecules suppress the immune system far more specifically than steroids and regimens that cause lymphopenia. Cyclosporin G and IMM 125 (analogues of cyclosporine) and FK506 are the only drugs that selectively inhibit T-cell proliferation by blocking cytokine synthesis. The primary action of rapamycin and leflunomide appears to be an inhibition of the actions of cytokines and growth factors on T, B, and some nonimmune cells. T and B cells are more sensitive than nonimmune cells to the depletion of purines and pyrimidines caused by mizoribine, mycophenolic acid, and brequinar sodium. Nucleotide depletion causes interruption of DNA synthesis and glycosylation of adhesion molecules in immune cells. Further differentiation of T and B cells after proliferation into fully functional immune cells is inhibited by unknown mechanisms by brequinar and deoxyspergualin. On the basis of preclinical studies, these drugs may effectively suppress clinical rejection that is (1) acute (all drugs), (2) chronic (rapamycin, leflunomide, and mycophenolic acid), or (3) antibody-mediated (brequinar, deoxyspergualin, mycophenolic acid, and rapamycin). Some drugs (FK506, deoxyspergualin, mycophenolic acid, rapamycin, and leflunomide) may reverse acute rejection refractory to conventional immunosuppression. These new drugs not only block different biochemical steps that normally lead to fully functional T and B cells after stimulation by alloantigen, but their toxicity profiles also differ. Results from preclinical studies predict that use of selected combinations of these drugs in patients will be more effective, less nephrotoxic, less myelotoxic, and less broadly immunosuppressive than current regimens based on cyclosporine, T-cell depletion, steroids, and azathioprine ... at least, that's the idea! Or as former Vice President Dan Quayle said, "It's a question of whether we're going to go forward into the future, or past to the back."
 ...
PMID:New small molecule immunosuppressants for transplantation: review of essential concepts. 750 52

More immunosuppressive drugs than ever have recently graduated from the laboratory to extensive clinical trials of their safety and efficacy in transplant patients. None of these drugs is perfect, but they control different forms of rejection in stringent animal models more effectively than other immunosuppressants, and these novel molecules suppress the immune system far more specifically than steroids and regimens that cause lymphopenia. Cyclosporin A and FK506 are the only drugs that selectively inhibit T-cell proliferation by blocking cytokine synthesis. The primary action of rapamycin appears to be inhibition of the actions of cytokines and growth factors on T, B, and some nonimmune cells. T and B cells are more sensitive than nonimmune cells to the depletion of purines and pyrimidines caused by mizoribine, mycophenolate mofetil, brequinar sodium, and leflunomide. Nucleotide depletion causes interruption of DNA synthesis and glycosylation of adhesion molecules in immune cells. Further differentiation of T and B cells after proliferation into fully functional immune cells is inhibited by unknown mechanisms of brequinar and deoxyspergualin. On the basis of preclinical studies, these drugs may effectively suppress clinical rejection that is acute (all), chronic (rapamycin, leflunomide, mycophenolate mofetil), or antibody mediated (brequinar, deoxyspergualin, mycophenolate mofetil, rapamycin, leflunomide). Some drugs (FK506, deoxyspergualin, mycophenolate mofetil, rapamycin, leflunomide) may reverse acute rejection refractory to conventional immunosuppression. Not only do these new drugs block different biochemical steps that normally lead to fully functional T and B cells after stimulation by alloantigen, but their toxicity profiles also differ. Results from preclinical studies predict that use of selected combinations of these drugs will be more effective, less nephrotoxic, less myelotoxic, and less broadly immunosuppressive than current regimens based on cyclosporine, T-cell depletion, steroids, and azathioprine.
 ...
PMID:Mechanisms of action of new immunosuppressive drugs. 858 21

Assessment of the immune system's capability to respond to antigens with the generation of specific antibodies, whilst under the influence of a test article, is required in toxicity tests according to the European guideline for repeated dose toxicity testing of medicinal products. The purpose of this study in rats was to validate methodology for the determination of Keyhole Limpet Haemocyanin (KLH)-specific antibodies under the influence of an immunologically active compound. The immunosuppressant FK506, commercially available as Prograf, was administered orally (gavage) to five rats per sex per group at dosages of 0.5mg/kg per day or 3mg/kg per day, for a period of 4 weeks. On days 14 and 22, KLH was administered subcutaneously, with an adjuvant (AluGel), to the two treated groups and a control (i.e. without FK506 treatment) approximately 1h following administration of FK506. Terminal investigations included haematology parameters, titration of KLH-specific antibodies in serum (ELISA), macroscopic pathology, spleen and thymus weights, immunophenotyping of splenocytes (FACS analysis) and histopathology of the lymphatic tissues. At 3mg/kg per day a minimal reduction of subcutaneous KLH-induced granuloma formation and a moderate to marked reduction of germinal centre development (axillary lymph node and spleen) were observed. Reduced CD4+ (T-cell) counts were found in the spleen of males, consistent with a suppressed production of KLH-specific antibodies (IgG in both sexes, IgM in males only) and a higher incidence of atrophy in the periarteriolar lymphoid sheaths of males. Slight-to-moderate lymphopenia was present in both sexes at 3mg/kg per day. These findings are consistent with the known pharmacological activity of FK506. In conclusion, determination of antibody titres following immunisation of rats with KLH, with concurrent exposure to a drug, appears to be a valid method in the context of the immunotoxicity evaluation required by European regulation.
 ...
PMID:Validation of immune function testing during a 4-week oral toxicity study with FK506. 1509 57

Calcineurin inhibitors (CNIs) are routinely used in immunosuppressive therapy and both Cyclosporine (CsA) and Tacrolimus (FK506) show similar efficacies to prevent rejection and death within the first year after organ transplantation. However, their use is limited by side effects such as kidney damage, hypertension, onset of diabetes and hyperlipidemia. It is a consensus that compared with CsA, FK506 causes less changes in blood pressures, serum lipids and renal function. Nevertheless, FK506 use is associated with a higher incidence of post-transplant diabetes mellitus (PTDM). FTY720 is a new compound that has shown a protective effect in animal models with respect to rejection in transplantation, ischemia-reperfusion injury, autoimmune diseases and tumor development. FTY720 acts by altering lymphocytes homing from blood to peripheral lymphoid organs. In mice, FTY720 administered in combination with CsA during 21 days has prolonged skin allograft survival without causing significant renal changes. In a model of CsA-induced chronic nephropathy in rats, FTY720 administration prevented renal injury suggesting benefit from using a combination of these drugs. In a canine kidney allograft model, FTY720 in combination with low doses of CsA or FK506 showed an addictive anti-rejection effect without causing critical adverse effects. We therefore, investigated whether 21 days of FTY720 administration in association with FK506 could prevent renal damage and development of diabetes in mice. Mice receiving FK506 alone or FTY720 + FK506 during 21 days showed changes in kidney function and structure besides an increase in blood glucose and lymphopenia. The FTY720 + FK506 combination requires further investigation with an aim toward understanding the mechanisms involved with respect to side effects.
 ...
PMID:Tacrolimus in combination with FTY720--an analysis of renal and blood parameters. 1721 91

Calcineurin inhibitors such as cyclosporine (CsA) and tacrolimus (FK506) show similar efficacy to prevent rejection within the first year after organ transplantation. However, their use is limited by side effects, such as kidney damage, hypertension, new-onset diabetes, and hyperlipidemia. The consensus opinion suggests that compared with CsA, FK506 has fewer negative effects on blood pressure, serum lipids, and renal function. Nevertheless, FK506 use is associated with a higher incidence of posttransplantation diabetes mellitus. FTY720 is a new compound that has shown beneficial effects in animal models of rejection in transplantation, ischemia/reperfusion injury, autoimmune diseases, and tumor development. Our aim was to investigate whether FTY720 + tacrolimus association could provide additional immunosuppression without causing renal toxicity. FTY720 as a monotherapy or in association with FK506 was administered to C57BL/6 mice for 21 days to prevent skin graft rejection and to evaluate renal function and structure. Increased skin allograft survival in the FTY720 + FK506 group was associated with decreased cell numbers in the spleen, blood, and axillary lymph nodes. Changes in major histocompatibility complex (MHC) class II and intercellular adhesion molecule-1 (ICAM-1) expressions in splenocytes were also found in this group. The major effects already described for FK506 (diabetes) or FTY720 (lymphopenia) were observed after 21 days administration even when the drugs were associated. FTY720 associated with FK506 caused fewer changes in kidney structure, and blood glucose levels were lower than in FK506 monotherapy.
 ...
PMID:Skin allograft survival and analysis of renal parameters after FTY720 + tacrolimus treatment in mice. 1845 36