Biomedical subjects

Denise Pochinco

Publications and source records attributed to Denise Pochinco.

3 recordsLinked to original sources

PubMed2004

Leukocyte reduction of red blood cell transfusions does not decrease allosensitization rates in potential kidney transplant candidates.

A significant proportion of potential kidney transplant candidates continue to periodically require blood transfusions that carry a risk of allosensitization. Leukocyte reduction (leukoreduction) of blood products has been proved to reduce transfusion-associated allosensitization in patients with hematologic malignancies; however, the effect in potential kidney transplant candidates is unknown. A total of 112 kidney transplant candidates who received red blood cell transfusions while on the transplant waiting list were identified retrospectively. Sixty received a transfusion before leukoreduction (non-LR), and 52 received a transfusion after the local implementation of universal leukoreduction of blood products (LR). There was no difference in transfusion-associated allosensitization rates in patients who received a transfusion during the two eras (non-LR 27% [16 of 60] versus LR 33% [17/52]; NS). Likewise, no difference was observed in subgroups identified as being at high risk of allosensitization (previous pregnancy, transplant, or five or more previous transfusions) or at low risk (no previous allogeneic exposures) (high risk: non-LR 52% versus LR 55%; low risk: non-LR 10% versus LR 8%). Multivariate analysis revealed previous pregnancy to be the only significant risk factor associated with transfusion-associated allosensitization (relative risk, 8.2; 95% confidence interval, 2.4 to 24.0; P = 0.0001). Leukoreduction, in particular, was not associated with any protective effect. In summary, leukoreduction of red blood cell transfusions does not confer any protection against transfusion-associated allosensitization for potential kidney transplant candidates. Physicians who care for patients with ESRD must continue to practice careful transfusion avoidance while alternative strategies to minimize transfusion associated allosensitization are sought.

Adult↗

PubMed2003

Heightened peripheral blood lymphocyte CD69 expression is neither sensitive nor specific as a noninvasive diagnostic test for renal allograft rejection.

It has been reported that acute allograft rejection is associated with heightened expression of the peripheral blood lymphocyte (PBL) early activation marker CD69 and that this may serve as a potential biomarker of rejection. This study sought to determine whether PBL CD69 expression correlates with both acute clinical and subclinical renal allograft rejection as well as clinically inapparent cytomegalovirus (CMV) infection. Flow cytometric determination of PBL CD69 expression was performed at the time of clinical and protocol biopsies (n = 131) in 45 renal transplant recipients. Nineteen patients also underwent weekly monitoring of PBL CD69 expression for the initial 15 wk after transplantation. Simultaneous screening for CMV viremia was performed with a semiquantitative PCR assay. No differences were seen in either CD4+ or CD8+ lymphocyte CD69 expression between the biopsy diagnoses. CMV viremia however, independent of rejection, was associated with greater CD69 expression on CD8+ lymphocytes (17.8 +/- 10.4% versus 9.6 +/- 4.8%; P < 0.0001) but not CD4+ lymphocytes. No individuals experienced clinical CMV disease. Weekly monitoring of PBL CD69 expression did not change coincident with the diagnosis of rejection; however, CMV viremia coincided with a substantial rise in the proportion of CD8+69+ lymphocytes in a number of individuals. Thus, PBL CD69 expression is neither sensitive nor specific for the noninvasive diagnosis of renal allograft rejection. Furthermore, clinically inapparent CMV viremia is associated with heightened expression of this activation marker on CD8+ lymphocytes. This latter finding suggests that clinically inapparent CMV viremia may be a potential confounder for biomarkers of rejection that examine peripheral blood lymphocytes.

Antigens, CD↗

PubMed2001

Flow cytometric crossmatching in primary renal transplant recipients with a negative anti-human globulin enhanced cytotoxicity crossmatch.

Flow cytometric crossmatching (FCXM) and panel reactive antibody (PRA) screening techniques are more sensitive than anti-human globulin enhanced cytotoxicity (AHG-CDC) techniques at detecting anti-HLA antibodies. The clinical significance of a positive FCXM in primary renal transplant recipients with a negative AHG-CDC crossmatch is unclear. We performed retrospective FCXM and flow cytometric panel reactive antibody (FlowPRA) determinations in primary renal transplant recipients with a negative T cell AHG-CDC crossmatch and a negative B cell CDC crossmatch pretransplant. Eighteen (13%) of 143 patients exhibited a positive retrospective T cell FCXM. Of these patients, six (33%) experienced early graft loss with explant histology, demonstrating antibody-mediated rejection in five of six cases. The 12 patients with positive T cell FCXM who maintained their grafts experienced more adverse events posttransplant, including more early, steroid-resistant, and recurrent rejection. Furthermore, in a subgroup of patients undergoing protocol biopsies, those with a positive T cell FCXM exhibited more subclinical rejection. Anti-HLA antibodies were detected by FlowPRA in all 18 patients with a positive T cell FCXM, whereas AHG-CDC PRA detected antibodies in only 8 of 18 patients. Therefore, flow cytometric techniques identify sensitized primary renal transplant recipients undetected by AHG-CDC techniques. In those patients, a positive T cell FCXM is associated with an increased risk of early graft loss due to antibody-mediated rejection and may represent a relative contraindication to transplantation. Moreover, those patients are also at increased risk of severe and recurrent rejection, which may carry implications for long-term graft outcomes.

Adult↗