The predictive value for pulmonary infection by area over the neutrophil curve (D-index) in patients who underwent reduced intensity hematopoietic stem cell transplantation

c-D-index at day 11 can predict febrile neutropenia during chemotherapy in acute myeloid leukemia

Acute myeloid leukemia (AML) often requires long-term intensive chemotherapy for its cure. During chemotherapy, the patient always experiences neutropenia with readings below 500 cells/μL; this is often accompanied by pyrexia with a temperature of more than 101°F. This combination of neutropenia and fever is called febrile neutropenia (FN). A tool to sum up the daily severity of a patient’s neutropenia, the “D-index,” has been validated in some specific clinical settings. In this study, we examined whether the D-index is a useful predictor of the onset of FN. We recruited consecutive patients treated with induction and consolidation chemotherapy for newly diagnosed AML. We gathered all the FN events and their clinical background data retrospectively. Patients’ background, such as pre-existing conditions and disease status before the treatment, were analyzed using multivariate methods. All FN events during chemotherapy were evaluated for infection focus and causative organism. A total cohort of 51 cases (25 women, 26 men; median age 51 years, range 18–74) was analyzed. They displayed 171 neutropenic events (115 FN and 56 afebrile episodes) during chemotherapy, and complete neutropenic events were used in this study. Sensitivity and specificity analysis showed that the most useful cutoff value to predict the onset of FN was a cumulative D-index at day 11 (c-D11-index) of 718. The cumulative incidence of FN during chemotherapy was significantly higher in the group with c-D11-index ≥710 (80%) than in the group with c-D11-index <710 (39%) (P < 0.0001). Through multivariate analysis, the presence of diabetes mellitus and the c-D11-index were extracted as contributing factors to the onset of FN (P = 0.0087 and 0.0002, respectively). In conclusion, we can predict that AML patients receiving chemotherapy will experience the complication of FN when the c-D-index at day 11 is >710, with an odds ratio of 2.1.

D-index as a marker of bloodstream infections in patients with allogeneic hematopoietic stem cell transplantation

BACKGROUND

Neutropenia is a risk factor for development of infections; however, the direct effect of neutropenia on development of bloodstream infection (BSI) is not known. D-index, which is area between the neutrophil time curve and a neutrophil count of 0.5 × 10⁹ /L, incorporates the combined effect of severity and duration of neutropenia. We aimed to evaluate whether D-index can be used as a marker for BSI in patients with allogeneic stem cell transplantation.

METHOD

We conducted a retrospective cohort study of patients undergoing allogeneic stem cell transplantation between January 1, 2005, and September 30, 2015. The primary outcome measure was the development of BSI within 30 days of transplantation.

RESULTS

A total of 714 patients were included in the study of whom 101 developed BSI. Patients with BSI had a significantly higher median D-index value compared with patients who did not have BSI (4990 vs. 3570, P < .001). As a marker, the performance of the D-index was similar to that of the duration of profound neutropenia (P = .18) and significantly better than the total duration of neutropenia (P = .001).

CONCLUSION

The D-index performed better than the total duration of neutropenia as a marker for BSI in patients with allogeneic stem cell transplantation. There was no difference between D-index and, a more easily calculable indicator, duration of profound neutropenia.

The D-index is not correlated with invasive fungal infection during the early-post engraftment phase among allogeneic hematopoietic stem cell transplant recipients

The D-index assesses neutropenia dynamics. Prolonged neutropenia is a major risk for invasive fungal infection (IFI); we hypothesized that D-index is predictive of IFI risk. We retrospectively reviewed 789 adults who underwent allogeneic hematopoietic transplant (HSCT) from 1/1/2005 to 9/30/2015. Medical records were reviewed from transplant (D0) through Day 100. The D-index was calculated as area over the neutrophil curve until engraftment. 714 patients were included for analysis. Sixteen (2%) developed probable (11) or proven (5) IFI. Median time to IFI was 40 days (range 8-98) after HSCT. Groups with and without IFI did not differ significantly in duration of mild or profound neutropenia. Median D-index of those with IFI was 4293 days neutrophil/µl compared to 3590 days neutrophil/µl for those without IFI (P = 0.17). Patients who were neutropenic on D0 showed higher rates of IFI than those who were not (10/123 [8%] vs 6/591 [1%]; P < 0.001). Only 2% developed IFI, likely due to mold-active antifungal prophylaxis. The D-index was not significantly higher in those with IFI. Duration of profound neutropenia and neutropenia at D0 may be better markers for IFI among HSCT recipients during the first 30 and 100 days after transplant.

c-D-index is a risk factor for prolonged febrile neutropenia during chemotherapy in patients with acute myeloid leukemia

BACKGROUND

D-index is a recently established clinical tool for assessing neutropenia severity. This study examined whether the D-index can predict the onset of various infections in patients with febrile neutropenia (FN).

METHODS

We retrospectively investigated FN events in consecutive patients aged < 65 years who were treated for newly diagnosed acute myeloid leukemia at our institution. We collected data on all FN events during chemotherapy and evaluated the association of FN severity with infectious events.

RESULTS

This study included 35 patients (18 women and 17 men; median age, 51 years [range 18-65 years]) with 122 FN events. The response rate to induction chemotherapy was 60% (21/35), and all but one patient survived the treatment. The D-index did not predict FN onset. However, in multivariate analysis, high-dose cytarabine and total D-index were statistically significant explanatory factors for microbiological-proven infections. In addition, multivariate analysis showed that diabetes mellitus is the only risk factor for FN onset. Furthermore, older age, consolidation therapy, and cumulative D-index (c-D-index) were risk factors for prolonged FN. The FN period was the longest in patients with respiratory infections.

CONCLUSION

The D-index did not predict the onset of infection. However, FN duration might be prolonged during consolidation therapy in elderly patients with diabetes mellitus, and it is important to manage respiratory infections. These findings indicate the c-D-index is a useful tool to predict prolonged FN.