In what can be called a medical breakthrough, a Singaporean, who had a bone marrow transplant in July last year, survived a recent kidney transplant operation without taking drugs to prevent rejection.
Koh Hock Heng, 43, was diagnosed with kidney failure four years ago. Two years later, doctors discovered he also had a stem cell disease called myelodysplastic syndrome (MDS).
According to Dr Pary Sivaraman, Consultant Renal Physician, Department of Medicine (NUH), "MDS is a pre-leukemia disease in which the bone marrow doesn't function properly. It needs intensive chemotherapy and treatment can be quite toxic, which is not possible for someone with renal failure".
In the case of Koh, both the transplanted bone marrow and kidney came from his younger brother, which cured his pre-leukemia illness first and then took him back to a normal life. When he received a kidney from his brother the following year after the marrow transplant, his body could tolerate it better even with fewer drugs.
The doctors used non-myeloablative stem cell transplantation (NMT), which involves using significantly lower doses of chemotherapy and radiation compared to standard bone marrow transplantation therapy.
In the procedure, the patient and donor stem cells blend completely, so that later on, the patient's body does not reject the donor's kidney. The two immune systems blended in Koh's body after the bone marrow transplant and now his younger brother's bone marrow cells have completely taken over his own immune system.
Being the first person in Asia to undergo such medical treatments, Koh does not need to take anti-rejection medicine for the rest of his life.
Doctors at the National University Hospital said Koh was one of the few transplant patients in the world who do not need to take medication for life to prevent his body rejecting the new kidney.
Even though Koh does not take any medication to suppress his immune system, the kidney will not undergo rejection. So basically he does not need any medication at all which is something we cannot achieve in standard kidney transplants.
Dr Sivaraman calls their procedure the "holy grail" in transplantation. It is hoped that in the future, this medical breakthrough can be applied to other kidney patients who require a transplant but who do not have leukemia. They too can benefit from a healthy new kidney without the risk of rejection and without the need to take drugs for the rest of their lives.