CARE AND MONITORING OF THE TRANSPLANT PATIENT
(for more specifics on the process of obtaining and managing a transplant through the UW-VMTH, see SPECIFIC ISSUES RELATING TO FELINE KIDNEY TRANSPLANTATION AT THE UNIVERSITY OF WISCONSIN)
After discharge from the hospital you will need to be observant of your cat's general health and have periodic monitoring of its blood performed. Early detection of problems in the postoperative period, especially for signs of rejection, can be instrumental in successfully reversing the rejection episode and salvaging the transplanted kidney.
Observation. The first signs of a rejection episode will most likely be a behavioral change in your cat. Loss of appetite, depressed attitude, malaise, loss of energy, vomiting, etc. may indicate a rejection episode. It is possible that early rejection may be picked up on a routine monitoring visit by an increase in serum creatinine or decreased urine specific gravity. However, it is more likely that you will observe a change that should be brought to the attention of your veterinarian (see rejection section below).
Monitoring. Measurements of the cats weight, serum creatinine, BUN (blood urea nitrogen), PCV (packed cell volume), total protein, urine specific gravity (free catch urine only unless there is a need for a urine culture) and cyclosporine A trough level in the blood need to be done periodically to be sure that all is going well. In particular, it is important that the cyclosporine A level is closely monitored. As cats get healthier due to their transplant they seem to become more able to metabolize cyclosporine A (probably their liver is getting healthier too) and the blood levels can drop. Monitoring is done daily while the cat is in the hospital. After discharge it is usually done weekly for a month. Then the intervals are increased to biweekly and then monthly. Eventually, depending on the individual cat the monitoring may be done every 2-3 months. It is vital that the blood tests are drawn just before the next dose of cyclosporine to get an accurate assessment of the drug levels.
Immunosuppressive Drug Dosing. The antirejection drugs are given either once or twice a day. These are cyclosporine A (customized dose to obtain blood trough levels of 500 ng/ml as measured by HPLC) and prednisolone (0.25 mg/kg twice a day) and are given by mouth. After one month the prednisolone is changed to once a day at 0.25 mg/kg and the cyclosporine A decreased to achieve 12-hour blood levels about 250 ng/ml. See the section on Immunosuppressive Therapy for more detailed information.
Rejection episodes. Rejection needs to be rapidly identified to prevent loss of the kidney. Rejection is often first noticed as a general malaise, loss of appetite and loss of vigor in the recipient. The recipient should be immediately tested for serum creatinine levels and blood cyclosporine trough levels. A high creatinine combined with a low cyclosporine is considered de facto evidence of rejection. Occasionally a kidney biopsy may be needed to confirm the diagnosis. Since it takes some time to get cyclosporine levels done and we prefer not to lose this time in starting anti-rejection treatment, we will usually give anti-rejection medications if we suspect rejection is present and use response to this therapy as another diagnostic aid in identifying rejection. Serum creatinines will usually drop within 24 hours if rejection was present. Other causes of elevated creatinine can be cyclosporine toxicity or ureteral scarring and stricture. Thus, it may be necessary to examine the kidney by ultrasound to be sure that the problem is not an obstructed ureter. The cat is then administered fluids intravenously to promote urine production.
The further along a transplant patient survives from the time of surgery, the less risk certain problems present to them. See POSTOPERATIVE MILESTONES IN THE PROGRESS AND MANAGEMENT OF THE TRANSPLANT RECIPIENT for a synopsis of these risks.
Taking your cat home. Although the cat is on immunosuppressive drugs, it should be able to mingle with other cats (as long as they dont have known infectious diseases). It will be at a slightly increased risk for infections but this increased risk is not great enough to take undue precautions in managing your cat. Your cat will not require any special diet once it is home and is maintaining itself with a creatinine in the normal range. Your cat should get its normal vaccinations and otherwise be treated normally.
Enjoy your cat. If all has gone well your cat should be healthier, more active, have a good appetite and generally a much improved quality of life. Feline transplant patients have had survivals up to 6 years and more to date (early UC-Davis patients). Our longest survivor is out 4.5 years (as of February 2001) and still going strong. We still dont know what the maximum time limit is yet.