Creatinine is getting higher and higher, is it a rejection reaction? Or is it a BK virus infection?

Creatinine is a routine examination item for follow-up after kidney transplantation because it reflects kidney function. If creatinine is abnormally elevated, kidney transplant patients need to be vigilant. There are many reasons for the increase in creatinine, such as drug damage, relapse of nephritis, acute rejection or BK virus-related nephropathy.

After kidney transplantation, patients need to take immunosuppressants for a long time to reduce the occurrence of rejection reactions, thereby improving the long-term survival of the transplanted kidney. However, immunosuppressants can reduce the patient's immunity, and the BK virus lurking in the body will be activated, causing damage to the transplanted kidney and affecting the survival of the transplanted kidney. In short, if the suppression is too strong and the immunity is low, infection will occur; if the immunity is strong but the suppression is not enough, rejection will occur.

With the accumulation of clinical treatment experience, rejection and BK virus-related nephropathy are not difficult to treat once diagnosed. The difficulty lies in how to diagnose and distinguish them in the early stage. Since creatinine is not specific in the diagnosis of rejection and BK virus-related nephropathy, it is usually necessary to perform a puncture biopsy on the transplanted kidney to clearly diagnose the cause clinically. Obviously, this is a traumatic examination. Since the patient is in the supine position for puncture and is under local anesthesia, the patient can watch the doctor insert the thin puncture needle into the body and draw out the tiny renal tissue. The psychological fear is self-evident. In addition, there is uncertainty in puncture. Research data show that for BK virus-related nephropathy, the actual incidence rate of negative puncture can reach 10-36.5%. There are many reasons that can lead to false negative punctures. For example, BKV is mostly present in the renal medulla, and the renal medulla is located in the center of the kidney like the core of a fruit. Sometimes the puncture depth is not enough and the medulla is not penetrated, which will cause false negative results and cause confusion in treatment.

So, is there a detection method that can not only help relieve patients' pain, but also detect rejection and BK virus nephropathy at the same time, and at the same time has high accuracy? In fact, Ogen Diagnostics, a domestic company specializing in organ transplant rehabilitation monitoring, launched a non-invasive AlloK seq® detection technology as early as 2018: by detecting the content of free DNA from donor kidneys that has fallen off due to cell apoptosis in the blood and urine of patients after transplantation, to identify rejection and BK virus-related nephropathy. The scientific principle of this detection technology is that the blood and urine of transplant patients carry free DNA produced by donor kidney cells. When the patient is in a stable state after surgery, the ddcfDNA content in the blood and urine is relatively stable. When the transplanted kidney is damaged, the ddcfDNA content will change. Moreover, the damage caused by rejection and BK virus-related nephropathy is different, which can be distinguished by ddcfDNA detection in blood and urine.