¹Afaf S. Abdel Rahman, ¹ Nehal MA. Fahim, ¹Abeer A. El Sayed, ¹Soha AR. El Hady, ²Yasser S. Ahmad
Departments of ¹Microbiology & Immunology and ²Internal
Medicine & Nephrology, Faculty of Medicine,
Renal transplantation, in most countries, is based on human
leukocyte antigen (HLA) matching of the donor kidney with the recipient.
Traditional human leukocyte antigen matching is based on defining human
leukocyte antigen specificities by antibodies utilizing cytotoxicity crossmatch
techniques. Newer techniques have emerged, which challenge the accuracy of
serological typing and crossmatching. We compared the results of the standard
complement- dependent cytotoxicity crossmatch (CDCXM) with the anti-human
globulin augmented cytotoxicity (AHG-CDC), and Flowcytometry
crossmatch (FCXM) for the detection of anti-HLA antibodies in 150
pre-transplant patients. The development of post-transplantation sensitization
was screened utilizing these three techniques within two weeks post-operative
and correlated with rejection episodes. Comparison between the results of CDCXM
and AHG-CDC in 150 recipients, revealed no significant correlation (P>0.05).
When comparing these results with that of FCXM in 50 recipients a significant
correlation was shown (P<0.05). Relative to CDCXM, the sensitivity of
AHG-CDC was 100%, specificity 97.4%, positive predictive value 92.3%, and
negative predictive value 100%. On the other hand, the sensitivity of FCXM was
100%, specificity 76.3%, positive predictive value 57.1%, and negative
predictive value 100%. According to the results of CDCXM, AHG-CDC, and FCXM, no
difference was detected between pre- and posttransplant anti-HLA sensitization
within two weeks after the operation. Patients with negative cytotoxicity
crossmatch (CDCXM and AHG-CDC) and positive FCXM may have an increased risk of
early graft loss and may represent a relative contraindication to transplantation.
Given the important theoretical advantages of FCXM over the CDC XM, further
testing of the clinical relevance is warranted.