Flow cytometric crossmatching and panel-reactive antibodies in chronic renal failure patients

Association of C1q Binding Status With De Novo HLA Antibody Clinical Features and Allograft Function in Kidney Transplantation Patients During Eight Years of Dynamic Follow-up

BACKGROUND

C1q-binding donor-specific antibody (DSA) is detrimental to transplanted kidney function. However, the factors that affect C1q binding status are unclear.

METHODS

A total of 519 samples from 129 consecutive kidney transplantation patients during 8 years of dynamic follow-up were collected for HLA antibody (Ab) screening and C1q detection.

RESULTS

Among the detected HLA Abs, the majority were class II, and the DQ subtypes composed the highest proportion. The C1q-binding Abs were all HLA-II, and the DQ subtypes had the highest rate of C1q positivity. With a cutoff mean fluorescence intensity (MFI) value of 7349, the sensitivity and specificity of detecting C1q-binding Abs from all HLA-II Abs were 84.48% and 83.56%, respectively. Additionally, C1q is more likely to be bound by DSA than non-donor-specific antibody (NDSA). Compared with free DSA/NDSA, the MFI values of C1q-binding DSA/NDSA are more closely correlated with serum creatinine levels and reflect the effect of anti-antibody-mediated rejection treatment more sensitively.

CONCLUSIONS

HLA-II Abs (particularly DQ subtypes), high titers of Abs, and DSA are important relevant factors of C1q positivity. The MFI value of C1q-binding DSA may be a useful clinical indicator of HLA antibody-mediated graft injury before the appearance of histologically typical humoral rejection.

Detection of Antileukocytic Antibodies in Blood Serum using Lymphocytes and Latex Microspheres Carrying HLA-Antigens upon Alloimmunization of Women with Recurrent Pregnancy Loss

Anti-HLA-antibodies were detected using cross-reaction of blood serum with allogenic T and B cells and latex microspheres coated with HLA-I and HLA-II antigens. HLA+ and HLA-sera obtained from women before and after allogeneic immunization were tested. The results obtained by these methods significantly differed. The test with latex microspheres detected antibodies to HLA-I and HLA-II antigens with high sensitivity and specificity and can be used for assessment of clinical significance of alloantibody detection when using alloimmunization in the therapy of gestation disorders.

Is flow cytometry crossmatch analysis using sera with different dilutions important for pretransplant analysis? A case report

The most effective form of treatment for chronic renal failure is kidney transplantation from a cadaver or a living donor. For a kidney transplant to be successful, tissue compatibility and a lack of donor-specific anti-human leukocyte antigen (HLA) antibodies in the circulation of the patient are vital, in addition to ABO blood group compatibility. The presence of anti-HLA antibodies is assayed before transplantation using various methods, but because organ rejections have been observed in previous studies, different techniques are required to detect anti-HLA antibodies. Today, flow cytometry crossmatching is one of the most important and effective techniques in testing for donor-specific anti-HLA antibodies (DSAs). If weakly positive serum is assayed after serial dilution, it can yield high positivity. Herein, we describe the differences between the results for diluted and undiluted weakly positive sera studied using the flow cytometry crossmatch (FCXM) technique. In a recent study, the sera of weakly FCXM-positive patients were diluted 1/50, and the FCXM test was repeated. The use of diluted serum eliminated the effect of the prozone so that the DSAs could be detected.