Impact of the D-index deduced from duration and intensity of neutropenia following chemotherapy on the risk of invasive fungal infection in pediatric acute myeloid leukemia

D-index and invasive fungal infections (IFIs) in adult acute myeloid leukemia (AML) patients with the first episode of febrile neutropenia

INTRODUCTION

This study aimed to evaluate the performance of the D-index, a calculated measure of neutropenic burden, in predicting the risk of invasive fungal infections (IFIs) in acute myeloid leukemia (AML) patients.

METHODS

A retrospective study of adult AML patients who received the first induction chemotherapy and developed febrile neutropenia was conducted. Clinical characteristics, laboratory data, and the calculation of the D-index and cumulative D-index (c-D-index) were collected and analyzed between patients with and without IFIs.

RESULTS

A total of 101 patients were included, with 16 (15.8%) patients who developed IFIs. Clinical characteristics, antifungal prophylaxis, and AML cytogenetic risk were similar between patients with or without IFIs. The results showed that the D-index and c-D-index were more effective in predicting IFIs than the duration of neutropenia. With the D-index cutoff of 7083, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 81.3%, 83.5%, 48.2%, and 95.9%, respectively. c-D-index at 5625 revealed sensitivity, specificity, PPV, and NPV for IFIs of 68.8%, 68.2%, 28.9%, and 92.1%, respectively. Using this cutoff of c-D-index, patients without IFIs were overtreated with an antifungal regimen in 45 (52.9%) cases.

CONCLUSION

The D-index and c-D-index were helpful indicators for defining the risk of IFIs in AML patients with febrile neutropenia.

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.

Early reconstitution of lymphocytes after allogenic hematopoietic stem cell transplantation affects chronic graft-versus-host disease

BACKGROUND

Lymphocyte reconstitution after hematopoietic stem cell transplantation (HSCT) is important for the prevention of infections, as well as for the reduction of recurrence, by its graft versus tumor effect. However, these lymphocytes may also play a role in the development of graft-versus-host disease (GVHD). Few studies have investigated the association between lymphocyte reconstitution and clinical outcomes after HSCT.

METHODS

This issue was investigated by retrospectively analyzing pediatric patients who received their first allogeneic-HSCT using a newly developed parameter, the LD-index, which evaluates both the intensity and duration of lymphopenia. A total of 101 patients underwent allo-HSCT from April 2007 to August 2019 in our hospital. Excluding patients who died before lymphocyte recovery or underwent multiple HSCT, 78 patients were analyzed for associations between the LD-index with various factors relating to HSCT.

RESULTS

A significantly high association was observed between a low LD-index and the incidence of chronic GVHD (P = 0.0019). Analysis of predictive factors for chronic GVHD was carried out using univariate analysis. Lower LD-index, donor source and duration of lymphopenia were found to be significant factors associated with chronic GVHD. Multivariate analysis, however, only identified an association between a lower LD-index and an increased incidence of chronic GVHD (P = 0.00081).

CONCLUSIONS

Early reconstitution of lymphocytes after allo-HSCT is associated with a higher incidence of chronic GVHD.

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.

Comparison of myelosuppression using the D-index between children and adolescents/young adults with acute lymphoblastic leukemia during induction chemotherapy

BACKGROUND

Adolescents and young adults (AYAs) with acute lymphoblastic leukemia (ALL) are more likely to have chemotherapy-related complications than children. In addition, several reports have shown that infections account for most of the therapy-related mortality during cancer treatment in AYAs. Thus, we hypothesized that chemotherapy-induced myelosuppression is more severe in AYAs than in children, and the state of neutropenia was compared between children and AYAs using the D-index, a numerical value calculated from the duration and depth of neutropenia.

PROCEDURE

This study retrospectively analyzed 95 patients newly diagnosed with ALL at our institution between 2007 and 2019. Of these, 81 were children (<15 years old) and 14 were AYAs (≥15 years old). The D-index and duration of neutropenia during induction chemotherapy for ALL were compared between children and AYAs.

RESULTS

The median D-index of children was significantly higher than that of AYAs (8187 vs 6446, respectively, P = .017). Moreover, the median duration of neutropenia was also significantly longer in children than in AYAs (24.0 days vs 11.5 days, respectively, P = .007).

CONCLUSION

Contrary to our expectations, myelosuppressive toxicity during induction chemotherapy for ALL was more severe in children than in AYAs.