Risk Factors for Candidemia After Open Heart Surgery: Results From a Multicenter Case-Control Study

BACKGROUND

Candida species are among the most frequent causative agents of health care-associated bloodstream infections, with mortality >40% in critically ill patients. Specific populations of critically ill patients may present peculiar risk factors related to their reason for intensive care unit admission. The primary objective of the present study was to assess the predictors of candidemia after open heart surgery.

METHODS

This retrospective, matched case-control study was conducted in 8 Italian hospitals from 2009 to 2016. The primary study objective was to assess factors associated with the development of candidemia after open heart surgery.

RESULTS

Overall, 222 patients (74 cases and 148 controls) were included in the study. Candidemia developed at a median time (interquartile range) of 23 (14-36) days after surgery. In multivariable analysis, independent predictors of candidemia were New York Heart Association class III or IV (odds ratio [OR], 23.81; 95% CI, 5.73-98.95; P < .001), previous therapy with carbapenems (OR, 8.87; 95% CI, 2.57-30.67; P = .001), and previous therapy with fluoroquinolones (OR, 5.73; 95% CI, 1.61-20.41; P = .007). Crude 30-day mortality of candidemia was 53% (39/74). Septic shock was independently associated with mortality in the multivariable model (OR, 5.64; 95% CI, 1.91-16.63; P = .002). No association between prolonged cardiopulmonary bypass time and candidemia was observed in this study.

CONCLUSIONS

Previous broad-spectrum antibiotic therapy and high NYHA class were independent predictors of candidemia in cardiac surgery patients with prolonged postoperative intensive care unit stay.

Comparison of T-cell-depleted BMT and PBPCT with respect to chimerism, graft rejection, and leukemic relapse

Chimerism analysis by DNA-based methods is a valuable diagnostic tool for monitoring engraftment and leukemic relapse after allogeneic BMT or PBPC transplantation (PBPCT). We investigated the chimerism after T-cell-depleted BMT (n = 32) in comparison with T-cell-depleted PBPCT (n = 39). BM grafts were T-cell depleted using the Campath-IgM antibody plus complement. For T-cell depletion of the PBPC grafts, a selection of CD34+ cells with or without a subsequent CD2/3 depletion was performed. In all patients, the T-cell dose of the transplant was < 10(6)/kg body weight. Between day 13 and day 120 after transplantation, chimerism analysis was done by RFLP or amplified fragment length polymorphism (PCR-AFLP), with a detection limit of 1%-5% recipient cells. In the BMT group, 8 of 32 (25%) patients showed a mixed chimerism, but only one graft rejection and no leukemic relapse occurred after a median follow-up of 41 (3-84) months. All patients with PBPCT revealed a complete chimerism of their granulocytes, and 38 of 39 patients showed complete chimerism of their lymphocytes. Follow-up time in these patients is 7 (2-21) months, with no graft rejection and two leukemic relapses. G-CSF-mobilized PBPC are superior to BM cells for full engraftment even after T-cell-depleted transplantation. The more relevant factor for developing complete chimerism seems to be the quantity and possibly the quality of the stem cells rather than the residual T-cell load of the graft. However, a mixed chimerism of the lymphocytes early after transplantation does not predict a higher rate of graft rejection or leukemic relapse.

Collection of allogeneic peripheral blood progenitor cells by two protocols on an apheresis system

BACKGROUND

Granulocyte-colony stimulating factor-mobilized allogeneic peripheral blood progenitor cells (PBPCs) are replacing bone marrow in transplantation for the treatment of several hematologic malignancies. The advantages of PBPCs are offset by the donor-associated disadvantages of granulocyte-colony stimulating factor side effects and the risk of apheresis-like platelet loss.

STUDY DESIGN AND METHODS

For each individual, the first donation of allogeneic PBPCs by apheresis on the Spectra, using either the standard protocol Version 4.7 (45 donors, [Version 4.7]) or the AutoPBSC (60 donors, [AutoPBSC]) was compared. Between July 1995 and May 1996, all donors enrolled underwent Version 4.7 apheresis. Since May 1996, the majority of donors underwent AutoPBSC apheresis. For statistical analysis, only data from the first apheresis for each individual donor was considered for independent values.

RESULTS

These results indicate a similar collection efficiency for CD34+ cells in the first apheresis of each donor (54% Version 4.7 vs. 53% AutoPBSC, p = 0.8). The apheresis time was longer with the AutoPBSC (233 min vs. 251 min, p = 0.005), whereas the loss of platelets was significantly lower (p < 0.001) with the AutoPBSC (28% vs. 19%). The mean number of CD34+ cells collected in the first apheresis component was 4.0 x 10(8) (Version 4.7) versus 3.8 x 10(8) (AutoPBSC).

CONCLUSION

Both apheresis protocols collect sufficient numbers of PBSCs for allogeneic transplantation. The AutoPBSC operates in a fully automatic fashion, avoiding manual adjustment and interindividual variations. The loss of platelets is lower with AutoPBSC than with Version 4.7, but the apheresis time is slightly longer.

Mobilization and collection of allogeneic peripheral blood progenitor cells for transplantation

A median dose of 11 (6-17) microg G-CSF per kg and day was given to 96 (49 female, 47 male) healthy family donors in order to mobilize and to collect peripheral blood progenitor cells (PBPC) for allogeneic transplantation. Donor age was 36 (17-76) years. The leukocytes of the donors increased to 46 (12-115) x 10(9)/l on days 4-6 of G-CSF treatment with a median of 71 (2-657) CD34+ cells per microl, respectively. Female and older donors seem to have a lower response to G-CSF. About 32% of the donors suffered from side-effects of G-CSF requiring analgetics. A total of 197 stem cell aphereses were performed using the COBE Spectra cell separator. Median apheresis time was 225 (118-300) min processing 11.8 (5.7-20) l blood, collecting 5.3 (1.7-14.9) x 10(10) nucleated cells and containing 0.7 (0.1-3.7)% CD34+ cells. Severe citrate toxicity occurred in 5% of the donors. Retransfusion of autologous platelets post apheresis was necessary in 16% of the donors because of a platelet count <80 x 10(9)/l. An insufficient number of stem cells was collected in four female donors due to a very poor response to G-CSF. In conclusion, the collection of allogeneic G-CSF-mobilized PBPC is safe and effective. One or two aphereses were sufficient in 91% of the donors to achieve >4 x 10(6) CD34+ cells per kg. In 4% of the donors an additional bone marrow harvest or the use of an alternative donor was necessary because of a poor mobilization.

Haematopoietic reconstitution after autologous transplantation of CD34(+)-selected versus non-selected peripheral blood progenitor cells

Selection of CD34+ cells for autologous transplantation is increasingly being used to reduce potential tumor cell contamination of the autograft. Haematopoietic reconstitution in 40 patients after transplantation of CD34(+)-selected versus non-selected G-CSF-mobilized PBPC was compared and was almost identical in the two groups of patients. Delayed platelet engraftment was only observed in patients transplanted with a CD34+ cell dose of < 2.5 x 10(6)/kg body weight. It has to be shown whether the positive selection of CD34+ cells will improve the disease free survival after autologous PBPC transplantation.

Improved lectin agglutination method for T-cell depletion of HLA-mismatched bone marrow grafts in children

For T-cell depletion in HLA-nonidentical bone marrow transplantation of children with malignant diseases, we improved the original lectin/rosetting method described in 1981 by adding anti-CD2/3 coated donor red blood cells to the combination to achieve lectin agglutination in one step. Further improvements in handling led to a shortened and simplified method and better quality of the graft. Five bone marrow grafts prepared with this modified protocol contained a median number of 6 (0-28) x 10(4) T-cells per kg, corresponding to 0.02 (0-0.08)% CD3+ cells and 6 (3.7-10.5) x 10(6) CD34+ cells per kg at a median body-weight of 7 (5-38)kg. The overall recoveries after T-cell depletion were: NC 17 (10-44)%, CD34+ cells 61 (22-100)%, and CFU-GM 55 (29-212)%.

Combined CD34 positive plus CD2 negative selection for effective T-cell depletion as GvHD-prophylaxis in HLA-nonidentical blood progenitor cell transplantation

G-CSF mobilized, T-cell-depleted peripheral blood progenitor cells (PBPC) and T-cell-depleted bone marrow (BM) were given to seven children (6 AL, 1 SCID) to prevent severe graft-versus-host-disease (GvHD) as well as graft rejection after transplantation from HLA-nonidentical parental donors. BM was T-cell-depleted by lectin agglutination and E-rosetting. For T-cell-depletion of the PBPC grafts a combination of CD34+ selection with the Ceprate SC immunoadsorption system and a subsequent depletion of CD2+ cells with immunomagnetic Dynabeads was used. The overall recovery was 0.3 (0.1-1.2)% for nucleated cells, 29 (18-45)% for CD3+ cells, respectively. The purity of CD34+ cells was 87 (68-97)% with a 0.3(0.05-0.7)% residual CD3+ T-cell contamination. In spite of the large T-cell number in the PBPC grafts the combination of CD34 positive and subsequent CD2 negative selection achieved a more than 4 log T-cell depletion and prevents severe GvHD even in HLA-nonidentical transplantation. In addition, if a high dose of progenitor cells ensures stable engraftment, this new approach could increase the possibility of wider use of HLA-mismatched family donors for transplantation.

Chimerism analysis after allogeneic bone marrow transplantation with nonradioactive RFLP and PCR-AFLP using the same DNA

We describe a method combining RFLP and PCR-AFLP analyses for studying chimerism after allogeneic bone marrow transplantation. Using RFLP analysis alone with DNA probe hMFl 87% of 244 donor/recipient pairs revealed different specific bands. By examination of the identical DNA probes using PCR-AFLP, an additional 52% of the residual donor/recipient pairs could be identified. Thus, 94% of allogeneic transplantations can be monitored using a combination of RFLP and PCR-AFLP analyses at one locus.

T-Cell Depletion of Allogeneic Peripheral Blood Progenitor Cells for HLA-Nonidentical Transplantation in Children

Bei Patienten mit malignen Systemerkrankungen ohne HLA-kompatiblen Kno-chenmarkspender wurde neben Knochenmark die zusätzliche Transplantation T-Zell-depletierter peripherer Blutstammzellen von nichtidenten Familienspendern durchgeführt. Die primär verwendete Lektin/Rosetten-Methode führte nicht immer zu einer ausreichenden Depletion von T-Lymphozyten der allogenen Blutstamm-zellpräparate. Deshalb wurde eine Kombination aus primärer Selektion von CD34+-Zellen und anschlieβender immunmagnetischer T-Zell-Depletion entwickelt. Dieses neue Verfahren reduzierte bei einem guten Ertrag von Stammzellen die T-Lymphozyten unter 1 × 105 pro kg Körpergewicht. Vier Kinder wurden mit einer Kombination aus Knochenmark und peripheren Stammzellen bei 3 bis 4HLA-Dif-ferenzen transplantiert und zeigten eine rasche hämatopoetische Regeneration ohne schwere Komplikationen einer Spender-gegen-Wirt-Reaktion.

A simplified rapid method for restriction fragment length polymorphism analysis after bone marrow transplantation

A rapid and simple protocol for restriction fragment length polymorphism (RFLP) analysis using digoxigenin labeled DNA probes is presented. The method described gives consistently good results even with minute cell numbers. The method has been used to evaluate chimerism after bone marrow transplantation but could also find other applications.