Patients with kidney failure have to face a double dilemma - they often have to wait for years before they find a matching donor, sometimes succumbing to the illness even before they find one. Secondly, despite finding a matching donor, they still run at a risk of rejection - their body may treat the donor kidney as foreign and refuse to accept it. The body produces antibodies against the donor kidney; this ultimately leads to rejection of the transplant and brings the patient back to square one. This could also increase the chances of death in the patient.
Cross reaction between the donor kidney and the
recipient is avoided by matching of the HLA or Human Leucocyte Antigen. Subjecting the recipient to treatment with
certain medications prior to transplantation has made it possible to transplant
kidneys even if the HLA types do not match.
However, the duration of survival of these patients is less that of
those receiving HLA-matched kidney.
Hopkins Medical Institutions developed and tested one such pretreatment to
permit transplantation in patients having anti-HLA antibodies against the
donor, and thus at a high risk for rejection
this procedure, kidney failure patients initially underwent plasmapheresis
i.e. a process through
which antibodies that could react against the transplanted kidney were removed
from the blood. After each session,
patients were injected with intravenous immune globulin. The number of treatments depended upon the
baseline level of donor-specific anti-HLA antibodies. This process conditioned the patient's body to accept the
transplantation. Out of the 215
patients who underwent this process, 211 proceeded to transplantation. The patients received at least two
plasmapheresis sessions after the transplantation as well. As with normal transplantation procedures,
drugs that suppress immunity were administered in addition before, during and
researchers found that with this approach, the survival rates in the kidney
transplant patients were 90.6% at 1 year, 85.7% at 3 years, 80.6% at 5 years
and 79.7% at 8 years.
The survival rate at 3, 5 and
8 years was much better than patients who continued on dialysis (dialysis-only
group) or those receiving dialysis, some of whom underwent transplantation with
an HLA-compatible kidney during the study (dialysis-or-transplantation group).
In the study, the plasmapheresis procedure was
associated with minor adverse effects.
Anaphylaxis or a severe allergic reaction occurred in 3 patients. Some patients suffered from excessive
bleeding, which could have been associated with plasmapheresis.
researchers thus claim that pretreatment of renal transplant patients with
plasmapheresis and low dose immune globulin permits transplantation in patients
with anti-HLA antibodies against the donor kidney. These patients in addition show better survival as compared to
patients continuing on dialysis while waiting for a matched transplantation.
thus provides good news for patients who have a willing but non-matching donor.
The desensitization procedure will permit such transplantations
and hopefully reduce the waiting list of people in need of a matched kidney
However, since the study was conducted on a small
number of kidney failure patients and within a single center, the findings of
the study should be confirmed through a larger study.
Montgomery RA, Lonze BE, King KE, Kraus ES, Kucirka LM, Locke JE, et al.
Desensitization in HLA-Incompatible Kidney Recipients and Survival. N Engl J Med 2011; 365:318-326.