Economic evaluation of a preemptive treatment strategy for invasive fungal infection in neutropenic patients with hematological diseases.

We compared the expected medical costs of empirical and preemptive treatment strategies for invasive fungal infection in neutropenic patients with hematological diseases. Based on the results of two clinical trials with different backgrounds reported by Oshima et al. [J Antimicrob Chemother 60(2):350-355; Oshima study] and Cordonnier et al. [Clin Infect Dis 48(8):1042-1051; PREVERT study], we developed a decision tree model that represented the outcomes of empirical and preemptive treatment strategies, and estimated the expected medical costs of medications and examinations in the two strategies. We assumed that micafungin was started in the empirical group at 5 days after fever had developed, while voriconazole was started in the preemptive group only when certain criteria, such as positive test results of imaging studies and/or serum markers, were fulfilled. When we used an incidence of positive test results of 6.7 % based on the Oshima study, the expected medical costs of the empirical and preemptive groups were 288,198 and 150,280 yen, respectively. Even in the case of the PREVERT study, in which the incidence of positive test results was 32.9 %, the expected medical costs in the empirical and preemptive groups were 291,871 and 284,944 yen, respectively. A sensitivity analysis indicated that the expected medical costs in the preemptive group would exceed those in the empirical group when the incidence of positive test results in the former was over 34.4 %. These results suggest that a preemptive treatment strategy can be expected to reduce medical costs compared with empirical therapy in most clinical settings.

Allotype analysis to determine the origin of cytomegalovirus immunoglobulin-G after allogeneic stem cell transplantation.

BACKGROUND: Cytomegalovirus (CMV) reactivation still remains a major problem following allogeneic hematopoietic stem cell transplantation (HSCT). PATIENTS AND METHODS: In this study, we analyzed an immunoglobulin allotype, IgG1m(f), in CMV-seropositive HSCT recipients and their donors to distinguish donor-derived antibody from recipient-derived antibody. Eight donor-recipient pairs were informative regarding the appearance of donor-derived immunoglobulin-G (IgG), as the recipients were homozygous null for the IgG1m(f) allotype and the donors were IgG1m(f) positive. In these patients, total IgG, IgM, and allotype-specific IgG against CMV were measured by enzyme-linked immunosorbent assay. All subjects were monitored for at least 9 months after HSCT with (n = 5) or without (n = 3) CMV reactivation. RESULTS: Donor-derived CMV IgG tended to be elevated earlier in patients with CMV-seropositive donors than in those with CMV-seronegative donors. In 1 patient with a CMV-negative donor, donor-derived CMV IgG was not detected until late CMV reactivation. In 3 patients without CMV reactivation, donor-derived CMV IgG was also elevated within 1-6 months after HSCT. CONCLUSION: In conclusion, the CMV serostatus of the donor may be related to the timing of the appearance of donor-derived CMV IgG and the reconstitution of humoral immunity against CMV, regardless of the CMV antigenemia level after HSCT.

Persistence of recipient-derived as well as donor-derived clones of cytomegalovirus pp65-specific cytotoxic T cells long after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Cytomegalovirus (CMV)-specific CD8(+) cytotoxic T lymphocytes (CMV-CTLs) play a crucial role in preventing CMV disease. However, the actual in vivo dynamics of CMV-CTL clones after allogeneic hematopoietic stem cell transplantation (alloHCT) are still unclear. METHODS: Using a single-cell T-cell receptor repertoire analysis, we monitored clones and chimerism of CMV-CTLs in 3 CMV-seropositive alloHCT recipients from CMV-seronegative donors, with or without CMV reactivation. RESULTS: Nearly all of the CMV-CTLs during follow-up were CD45RA(-) CCR7(-) effector memory/CD45RA(+) CCR7(-) effector T cells, and were highly matured. In each case, the use of BV gene families was restricted, especially in BV5, 7, 28, and 29. Although no common predominant CMV-CTL clones were found, several shared motifs of complementarity-determining region-3 were identified among the 3 cases; QGA in all, TGE and TDT in Case 1 and Case 2, and RDRG in Case 2 and Case 3. In all cases, CMV-CTL clones that were detected for the first time after alloHCT persisted as the dominant clones. In Case 1, without CMV reactivation, recipient-derived CMV-CTLs exclusively persisted as a dominant clone, while all CMV-CTLs in the other 2 cases, with CMV reactivation, were donor derived. CONCLUSION: Clone monitoring and chimerism analyses should help to further clarify novel aspects of immuno-reconstitution after alloHCT.

Low-dose acyclovir prophylaxis for the prevention of herpes simplex virus disease after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Currently, acyclovir (ACV) at 1000 mg/day is widely used as prophylaxis in the early phase of hematopoietic stem cell transplant (HSCT) in Japan. However, low-dose ACV (200 mg/day) has been shown to prevent varicella zoster virus reactivation in the middle and late phases of HSCT. METHODS: Therefore, in this study, we decreased the dose of ACV to 200 mg/day in the early phase after HSCT. We analyzed 93 consecutive herpes simplex virus (HSV)-seropositive patients who underwent allogeneic HSCT for the first time in our center between June 2007 and December 2011. RESULTS: Before August 2009, 38 patients received oral ACV at 1000 mg/day (ACV1000) until day 35 after HSCT, whereas 55 patients received oral ACV at 200 mg/day (ACV200) after September 2009. We compared the cumulative incidence of HSV infection in the 2 groups. Oral ACV was changed to intravenous administration because of intolerance in 66% and 45% of the patients in the ACV1000 and ACV200 groups, respectively (P = 0.060). The probability of severe stomatitis (Bearman grade II-III) was 76% and 60% in the ACV1000 and ACV200 groups, respectively (P = 0.12). The number of patients who developed HSV disease before day 100 after HSCT was 0 in the ACV1000 group and 2 in the ACV200 group, with a cumulative incidence of 3.6% (P = 0.43). HSV disease in the latter 2 patients was limited to the lips and tongue and was successfully treated with ACV or valacyclovir at a treatment dose. CONCLUSION: ACV at 200 mg/day appeared to be effective for preventing HSV disease in the early phase after HSCT.

L-index as a novel index to evaluate both the intensity and duration of lymphopenia after allogeneic hematopoietic stem cell transplantation.

We retrospectively investigated L-index, which evaluates both the intensity and duration of lymphopenia after allogeneic hematopoietic stem cell transplantation (HSCT) (n = 50). L-index was defined as the area over the lymphocyte curve during lymphopenia (absolute lymphocyte count < 700/µL). We calculated the L-index from the start of conditioning to day 30 - L-index(30) - and to day 100 - L-index(100) - after HSCT. Multivariate analysis revealed that human leukocyte antigen mismatched donor, female gender, and non-lymphoid disease were significantly associated with high L-index(30). Grade III-IV acute graft-versus-host disease, alemtuzumab-containing regimen, and non-lymphoid disease were identified as independent significant factors for high L-index(100). Cytomegalovirus (CMV) antigenemia was detected > 3 cells/2 slides by C10/11 method in 30 patients (CMV-AG ≥ 3 group) and was not detected in 20 patients (CMV-AG < 3 group). Although no significant difference was seen in absolute lymphocyte count on day 30 between the 2 groups, the L-index(30) was significantly higher in the CMV-AG ≥ 3 group than in the CMV-AG < 3 group (P = 0.050). L-index(30) was identified as an independent factor on CMV reactivation in multivariate analysis, when it was treated as a dichotomous variable with a cut-off value of 22,318, determined by receiver operating characteristic curve analysis. In conclusion, both the intensity and duration of lymphopenia in early phase after HSCT evaluated on the basis of L-index(30) showed significant association with CMV reactivation.

A randomized controlled trial of cyclosporine and tacrolimus with strict control of blood concentrations after unrelated bone marrow transplantation.

Previous studies have suggested that tacrolimus (TAC) is more potent than cyclosporine (CSA) for prophylaxis against acute GVHD after allogeneic hematopoietic stem cell transplantation (HSCT). However, the target blood concentrations of these drugs in these studies were not consistent with the current recommendations. Therefore, we performed a randomized controlled trial to compare CSA and TAC with target blood concentrations of 500 and 15 ng/ml, respectively, to prevent acute GVHD after unrelated HSCT. A total of 107 patients were randomized into a CSA group (n=53) or a TAC group (n=54). During the first 4 weeks after HSCT, more than 90% of the patients achieved a mean blood concentration of between 80 and 120% of the target concentration. The incidences of grade II-IV and grade III-IV acute GVHD were 39.6 and 7.5% for the CSA group and 33.3 and 9.4% for the TAC group, respectively (P=0.41 and P=0.76). Other clinical outcomes, including overall survival, disease-free survival and the incidences of relapse, non-relapse mortality, and organ toxicities, were also equivalent. We concluded that the combinations of CSA and TAC with strict dose adjustment showed similar efficacies and toxicities as prophylaxis against acute GVHD after unrelated HSCT.

Single-cell T-cell receptor-ß analysis of HLA-A*2402-restricted CMV- pp65-specific cytotoxic T-cells in allogeneic hematopoietic SCT.

Cellular immunity is important for the control of CMV infection after allogeneic hematopoietic cell transplantation (Allo-HCT). However, the actual in vivo dynamics of CMV-specific cytotoxic T cell (CMV-CTL) clones are still unclear. We conducted clone monitoring of tetramer(+) CMV-CTLs in HLA-A*2402-positive donor-patient pairs, using a direct single-cell analysis that enabled the simultaneous identification and quantification of CTL clones. Clone dynamics were assessed in three cases with or without CMV reactivation. In Case-1 without CMV reactivation, despite the long-term use of systemic steroid, dominant clones of Donor-1 persisted and remained dominant. The CMV-CTLs at 1 year after Allo-HCT included a high proportion of CD45RA(+)CCR7(-) effector and CD27(-)CD57(+)mature T cells. On the other hand, in Cases-2 and -3 with CMV reactivation, novel clones appeared and became dominant during the follow-up. Their CMV-CTLs included more CD27(+) immature T cells at 1 year after Allo-HCT. With regard to clonotypes, HLA-A*2402-restricted CMV-CTLs tended to select BV7 and BJ1-1 genes for complementarity-determining region 3 (CDR3) of T-cell receptor (TCR)-ß. Specific amino-acid sequences of CDR3 of TCR-ß were found in each case. Patterns of clone reconstitution and phenotype would be different according to CMV reactivation. In vivo clone monitoring of CMV-CTLs could provide insight into the mechanism of immunological reconstitution following Allo-HCT.

Prediction of infectious complications by the combination of plasma procalcitonin level and localized infection before allogeneic hematopoietic cell transplantation.

We previously reported that the baseline C-reactive protein level did not predict infectious events after hematopoietic cell transplantation (HCT). Procalcitonin (PCT) has recently emerged as a powerful biomarker for the early diagnosis of bacterial infection. We evaluated the ability of the baseline PCT level to predict early infectious events after HCT in 79 recipients who received HCT between 2008 and 2012. The high-PCT group (≥ 0.07 ng/mL, n=27) frequently experienced documented infection (DI) (21.2% vs 44.4% at day 30, P=0.038) and bloodstream infection (BSI) (15.4% vs 37.0% at day 30, P=0.035). In a multivariate analysis, however, the baseline PCT level was not significantly associated with DI (HR 2.01, P=0.089) or BSI (HR 2.28, P=0.084). Localized infection, such as anal canal problems, before the start of conditioning was seen in 26 patients. When we stratified the patients according to the presence of elevated PCT and localized infection, the group with elevated PCT and localized infection (n=17) was significantly associated with increased DI (HR 3.40, P=0.0074) and BSI (HR 3.59 P=0.0078) after HCT. A larger prospective observation is warranted to confirm the impact of the baseline PCT level and clinical features on the outcome of HCT.

Hyperbilirubinemia in the early phase after allogeneic HSCT: prognostic significance of the alkaline phosphatase/total bilirubin ratio.

Hyperbilirubinemia in the early phase after allogeneic hematopoietic SCT (HSCT) is due to various causes. One of the most important causes of hyperbilirubinemia is veno-occlusive disease/sinusoidal obstructive syndrome (VOD/SOS). However, the prognosis of patients who are clinically diagnosed as SOS varies. We retrospectively evaluated 82 patients who underwent their first allogeneic HSCT. GVHD prophylaxis was a combination of short-term MTX and CsA (n=77) or tacrolimus (n=5). Thirty-three patients developed hyperbilirubinemia, with a bilirubin level of at least 2 mg/dL, within 20 days after HSCT. Of these patients, 24 were diagnosed as VOD/SOS using the modified Seattle criteria. Twenty-six recovered to a bilirubin level of <2 mg/dL. We focused on the serum alkaline phosphatase/total bilirubin ratio (ALP/TB) at the onset of hyperbilirubinemia and found that it significantly predicted the recovery from hyperbilirubinemia. OS was significantly higher in patients with a lower ALP/TB ratio (P=0.00056). In addition, a lower ALP/TB ratio was associated with better survival even in patients who were clinically diagnosed as SOS (P<0.001). The ALP/TB ratio at the onset of hyperbilirubinemia may be a useful predictor for the prognosis of hyperbilirubinemia and SOS early after HSCT.

Prediction of transplant-related complications by C-reactive protein levels before hematopoietic SCT.

Various biomarkers have been investigated with regard to their ability to predict the outcome of allogeneic hematopoietic SCT (HSCT). In this study, we retrospectively reviewed 90 recipients who received HSCT between 2007 and 2011 in our institution, and evaluated the predictive value of the baseline serum C-reactive protein (CRP) levels just before the initiation of conditioning for transplant-related complications after allogeneic HSCT. A receiver-operating characteristic curve revealed that the baseline serum CRP levels had an excellent predictive value for non-relapse mortality (NRM), with an area under the curve of 0.83. The sensitivity and specificity for NRM were 80% and 87%, respectively, with a cutoff of 0.6 mg/dL. With this cutoff value, multivariate analyses revealed that a higher baseline CRP level was an independent risk factor for NRM (HR 6.21, P<0.01), grade III-IV acute GVHD (HR 3.91, P=0.03) and poor overall survival (HR 3.27, P=0.0018). On the other hand, the baseline CRP level did not predict infectious events. These findings suggested that CRP levels before conditioning may be a useful predictive biomarker for poor survival.

Pharmacokinetics of CsA during the switch from continuous intravenous infusion to oral administration after allogeneic hematopoietic stem cell transplantation.

We investigated the serial changes in the blood CsA concentration during the switch from continuous intravenous infusion to twice-daily oral administration in allogeneic hematopoietic stem cell transplant recipients (n=12). The microemulsion form of CsA, Neoral, was started at twice the last dose in intravenous infusion in two equally divided doses. The area under the concentration-time curve during oral administration (AUC(PO)) was significantly higher than the AUC during intravenous infusion (AUC(IV)) (median 7508 vs 6705 ng/ml x h, P=0.050). The median bioavailability of Neoral, defined as (AUC(PO)/DOSE(PO)) divided by (AUC(IV)/DOSE(IV)), was 0.685 (range, 0.45-1.04). Concomitant administration of oral voriconazole (n=4) significantly increased the bioavailability of Neoral (median 0.87 vs 0.54, P=0.017), probably due to the inhibition of gut CYP3A4 by voriconazole. Although the conversion from intravenous to oral administration of CsA at a ratio of 1:2 seemed to be appropriate in most patients, a lower conversion ratio may be better in patients taking oral voriconazole. To obtain a similar AUC, the target trough concentrations during twice-daily oral administration should be halved compared with the target concentration during continuous infusion.