Chronic allograft nephropathy

Chronic Allograft Nephropathy (CAN) is a medical condition affecting the kidneys after a kidney transplant. It is characterized by a gradual loss of kidney function and is considered a leading cause of long-term graft failure. The term "chronic allograft nephropathy" has been largely replaced by the term "interstitial fibrosis and tubular atrophy" (IFTA) without specific etiology, as it more accurately describes the histological findings seen in these patients.

Causes

The exact cause of CAN is multifactorial and includes both immunologic and non-immunologic factors. Immunologic factors involve the recipient's immune response against the transplanted kidney, including acute and chronic rejection episodes. Non-immunologic factors include drug toxicity (especially from calcineurin inhibitors), hypertension, diabetes, and infections.

Symptoms

Symptoms of CAN are often nonspecific and can include a gradual decrease in kidney function, as evidenced by increased serum creatinine levels, decreased glomerular filtration rate (GFR), hypertension, and proteinuria. In many cases, symptoms may not become apparent until significant kidney damage has occurred.

Diagnosis

Diagnosis of CAN involves a combination of clinical assessment, laboratory tests, and histological evaluation of kidney tissue obtained through a biopsy. The biopsy is crucial for distinguishing CAN from acute rejection and other potential causes of kidney dysfunction post-transplantation.

Treatment

Treatment of CAN is challenging and focuses on slowing the progression of the disease. This may involve adjustments in immunosuppressive therapy, management of blood pressure and proteinuria, and addressing any modifiable risk factors such as diabetes and obesity. In cases where graft function continues to decline, dialysis or re-transplantation may be necessary.

Prevention

Preventive strategies for CAN include careful selection of donor and recipient, optimal management of immunosuppression to minimize drug toxicity while preventing rejection, and aggressive management of risk factors such as hypertension and diabetes.

Prognosis

The prognosis for patients with CAN varies. Early detection and intervention can slow the progression of the disease, but many patients eventually experience graft loss and return to dialysis or undergo a second transplant.