Kidney, Liver, and Heart Transplant
(See
BOXED WARNINGS.)
Cyclosporine capsules, (NON-MODIFIED), when used in high doses, can cause hepatotoxicity and nephrotoxicity.
Nephrotoxicity
It is not unusual for serum creatinine and BUN levels to be elevated during cyclosporine capsules therapy. These elevations in renal transplant patients do not necessarily indicate rejection, and each patient must be fully evaluated before dosage adjustment is initiated.
Nephrotoxicity has been noted in 25% of cases of renal transplantation, 38% of cases of cardiac transplantation, and 37% of cases of liver transplantation. Mild nephrotoxicity was generally noted 2 to 3 months after transplant and consisted of an arrest in the fall of the preoperative elevations of BUN and creatinine at a range of 35 to 45 mg/dl and 2.0 to 2.5 mg/dl, respectively. These elevations were often responsive to dosage reduction.
More overt nephrotoxicity was seen early after transplantation and was characterized by a rapidly rising BUN and creatinine. Since these events are similar to rejection episodes, care must be taken to differentiate between them. This form of nephrotoxicity is usually responsive to cyclosporine capsules dosage reduction.
Although specific diagnostic criteria which reliably differentiate renal graft rejection from drug toxicity have not been found, a number of parameters have been significantly associated to one or the other. It should be noted however, that up to 20% of patients may have simultaneous nephrotoxicity and rejection.
| Nephrotoxicity vs. Rejection |
Parameter | Nephrotoxicity | Rejection |
History | Donor > 50 years old or hypotensive | Antidonor immune response |
| Prolonged kidney preservation | |
| Prolonged anastomosis time | Retransplant patient |
| Concomitant nephrotoxic drugs | |
Clinical | Often > 6 weeks postop
p < 0.05, | Often < 4 weeks postop
p < 0.01, |
| Prolonged initial nonfunction | Fever > 37.5°C |
| (acute tubular necrosis) | Weight gain > 0.5 kg |
| | Graft swelling and tenderness |
| | Decrease in daily urine volume > 500 mL |
| | (or 50%) |
Laboratory | CyA serum trough level > 200 ng/mL | CyA serum trough level < 150 ng/mL |
| Gradual rise in Cr (< 0.15 mg/dL/day)
| Rapid rise in Cr (> 0.3 mg/dL/day)
|
| Cr plateau < 25% above baseline | Cr > 25% above baseline |
| BUN/Cr ≥ 20 | BUN/Cr < 20 |
Biopsy | Arteriolopathy (medial hypertrophy
,
| Endovasculitis
p < 0.001, (proliferation
,
|
| hyalinosis, nodular deposits, intimal | intimal arteritis
, necrosis, sclerosis)
|
| thickening, endothelial vacuolization, | |
| progressive scarring) | |
| Tubular atrophy, isometric vacuolization, | Tubulitis with RBC
and WBC
casts,
|
| isolated calcifications | some irregular vacuolization |
| Minimal edema | Interstitial edema
and hemorrhage
|
| Mild focal infiltrates
c | Diffuse moderate to severe mononuclear |
| | infiltrates
p < 0.0001 |
| Diffuse interstitial fibrosis, | Glomerulitis (mononuclear cells)
|
| often striped form | |
Aspiration Cytology | CyA deposits in tubular and | Inflammatory infiltrate with mononuclear phagocytes, |
| endothelial cells | macrophages, lymphoblastoid cells, and |
| | activated T-cells |
| Fine isometric vacuolization of | |
| tubular cells | |
| | These strongly express HLA-DR antigens |
Urine Cytology | Tubular cells with vacuolization and | Degenerative tubular cells, plasma cells, and |
| granularization | lymphocyturia > 20% of sediment |
Manometry | Intracapsular pressure < 40 mm Hg
| Intracapsular pressure > 40 mm Hg
|
Ultrasonography | Unchanged graft cross-sectional area | Increase in graft cross-sectional area |
| | AP diameter ≥ Transverse diameter |
Magnetic Resonance | Normal appearance | Loss of distinct corticomedullary junction, swelling, |
Imagery | | image intensity of parachyma approaching that |
| | of psoas, loss of hilar fat |
Radionuclide Scan | Normal or generally decreased perfusion | Patchy arterial flow |
| Decrease in tubular function | Decrease in perfusion > decrease in tubular function |
| (
131 I-hippuran) > decrease in perfusion
| Increased uptake of Indium 111 labeled platelets or |
| (
99m Tc DTPA)
| Tc-99m in colloid |
Therapy | Responds to decreased | Responds to increased steroids or |
| cyclosporine capsules | antilymphocyte globulin |
A form of chronic progressive cyclosporine-associated nephrotoxicity is characterized by serial deterioration in renal function and morphologic changes in the kidneys. From 5% to 15% of transplant recipients will fail to show a reduction in a rising serum creatinine despite a decrease or discontinuation of cyclosporine therapy. Renal biopsies from these patients will demonstrate an interstitial fibrosis with tubular atrophy. In addition, toxic tubulopathy, peritubular capillary congestion, arteriolopathy, and a striped form of interstitial fibrosis with tubular atrophy may be present. Though none of these morphologic changes is entirely specific, a histologic diagnosis of chronic progressive cyclosporine-associated nephrotoxicity requires evidence of these.
When considering the development of chronic nephrotoxicity it is noteworthy that several authors have reported an association between the appearance of interstitial fibrosis and higher cumulative doses or persistently high circulating trough concentrations of cyclosporine. This is particularly true during the first 6 posttransplant months when the dosage tends to be highest and when, in kidney recipients, the organ appears to be most vulnerable to the toxic effects of cyclosporine. Among other contributing factors to the development of interstitial fibrosis in these patients must be included, prolonged perfusion time, warm ischemia time, as well as episodes of acute toxicity, and acute and chronic rejection. The reversibility of interstitial fibrosis and its correlation to renal function have not yet been determined.
Impaired renal function at any time requires close monitoring, and frequent dosage adjustment may be indicated. In patients with persistent high elevations of BUN and creatinine who are unresponsive to dosage adjustments, consideration should be given to switching to other immunosuppressive therapy. In the event of severe and unremitting rejection, it is preferable to allow the kidney transplant to be rejected and removed rather than increase the cyclosporine capsules dosage to a very high level in an attempt to reverse the rejection.
Due to the potential for additive or synergistic impairment of renal function, caution should be exercised when co-administering cyclosporine capsules with other drugs that may impair renal function (see
PRECAUTIONS, Drug Interactions).
Thrombotic Microangiopathy
Occasionally patients have developed a syndrome of thrombocytopenia and microangiopathic hemolytic anemia which may result in graft failure. The vasculopathy can occur in the absence of rejection and is accompanied by avid platelet consumption within the graft as demonstrated by Indium 111 labeled platelet studies. Neither the pathogenesis nor the management of this syndrome is clear. Though resolution has occurred after reduction or discontinuation of cyclosporine capsules and 1) administration of streptokinase and heparin or 2) plasmapheresis, this appears to depend upon early detection with Indium 111 labeled platelet scans (see
ADVERSE REACTIONS).
Hyperkalemia
Significant hyperkalemia (sometimes associated with hyperchloremic metabolic acidosis) and hyperuricemia have been seen occasionally in individual patients.
Hepatotoxicity
Cases of hepatotoxicity and liver injury including cholestasis, jaundice, hepatitis, and liver failure have been reported in patients treated with cyclosporine. Most reports included patients with significant comorbidities, underlying conditions and other confounding factors including infectious complications and comedications with hepatotoxic potential. In some cases, mainly in transplant patients, fatal outcomes have been reported (see
ADVERSE REACTIONS, Postmarketing Experience).
Hepatotoxicity, usually manifested by elevations in hepatic enzymes and bilirubin, was reported in patients treated with cyclosporine in clinical trials: 4% in renal transplantation, 7% in cardiac transplantation, and 4% in liver transplantation. This was usually noted during the first month of therapy when high doses of cyclosporine capsules were used. The chemistry elevations usually decreased with a reduction in dosage.
Malignancies
As in patients receiving other immunosuppressants, those patients receiving cyclosporine capsules are at increased risk for development of lymphomas and other malignancies, particularly those of the skin. The increased risk appears related to the intensity and duration of immunosuppression rather than to the use of specific agents. Because of the danger of oversuppression of the immune system, which can also increase susceptibility to infection, cyclosporine capsules should not be administered with other immunosuppressive agents except adrenal corticosteroids. The efficacy and safety of cyclosporine in combination with other immunosuppressive agents have not been determined. Some malignancies may be fatal. Transplant patients receiving cyclosporine are at increased risk for serious infection with fatal outcome.