D-index: A New Scoring System in Febrile Neutropenic Patients for Predicting Invasive Fungal Infections

Risk Factors and Environmental Preventive Actions for Aspergillosis in Patients with Hematological Malignancies

(1) Background: Aspergillus spp. is a widely distributed filamentous fungus in the environment due to its high sporulation capacity. Currently, invasive aspergillosis (IA) is the most common invasive fungal infection in patients with hematologic malignancies, with high rates of mortality and morbidity. The multifactorial nature of the disease requires appropriate risk stratification to enable the most appropriate preventive measures to be adapted and implemented according to the characteristics of the patient. In this sense, the present research aims to identify recent risk factors and environmental control measures against invasive aspergillosis to establish preventive actions to reduce the incidence of invasive aspergillosis in hospitals. (2) Methods: We conducted a qualitative systematic review of the scientific literature on environmental risk factors and preventive measures for invasive aspergillosis in patients with hematologic malignancies. The Medline, Cochrane, and Scopus databases were consulted, following the PRISMA and STROBE guidelines. (3) Results: Adequate implementation of environmental control measures is presented as the most efficient intervention in terms of prevention to decrease the incidence of invasive aspergillosis in hospitals. Neutropenia, fungal contamination, insufficient environmental control measures in hospital and home settings, length of hospital stay, and anemia, are identified as independent risk factors. We show that HEPA, LAF, and Plasmair® systems are suitable methods to reduce the concentration of airborne fungal spores. Antifungal prophylaxis did not significantly influence IA reduction in our study. (4) Conclusions: Proper professional training and environmental control measures in hospitals are essential for the prevention of invasive aspergillosis. We should optimize risk stratification for patients with hematologic malignancies. Antifungal prophylaxis should be complementary to environmental control measures and should never be substituted for the latter. Studies should also be undertaken to evaluate the efficiency of environmental control measures against IA at patients' homes.

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.

D-index as a Risk Factor for Invasive Fungal Infections in Patients With Acute Lymphoblastic Leukemia From a Reference Hematology Center in Bogota

Introduction Patients with hematologic malignancies are susceptible hosts for the development of invasive fungal infection (IFI), one of the main life-threatening infectious complications faced by these patients. Currently, we have antifungal prophylaxis strategies and antifungal treatment schemes and we recognize that the main risk factor involved is profound and prolonged neutropenia. D-index and cumulative D-index are quantitative parameters, which determine the magnitude of neutropenia, as a function of duration and depth and their value correlates with the occurrence of IFI. Material and methods A case-control study in patients older than 18 years with acute lymphoblastic leukemia (ALL) was admitted between 2009 and 2019 at the National Cancer Institute for induction, consolidation and salvage chemotherapy. Results A total of 167 patients were included, who received 288 cycles of chemotherapy, the latter were considered the unit of analysis. A generalized estimating equations (GEE) model was designed to analyze correlated data; three quantitative and continuous variables of interest were included in this model: age (years), D-index and deep neutropenia (days). For the population D-index, an odds ratio (OR) = 1.000227 (95% CI 1.0002-1.0004); p < 0.001 was obtained. Conclusion D-index is associated with the development of IFI in patients with ALL, with an exponential increase in OR as the absolute value of the D-index increases.

Serial platelet level index improves prediction of pulmonary hemorrhage in patients with Stenotrophomonas maltophilia respiratory infections and thrombocytopenia

Patients with thrombocytopenia (platelet count &lt;150 × 103/μL) often develop pulmonary hemorrhage (PH) after Stenotrophomonas maltophilia (SM) respiratory infection, resulting in a high respiratory failure rate and increased mortality. Developing an efficient method for early prediction of PH in these patients may improve survival. This study aimed to evaluate risk factors in PH and to develop an index measuring serial platelet deficit to predict PH in patients with SM respiratory infection. Data of patients with SM respiratory infection and thrombocytopenia treated in a tertiary university hospital during 2018–2020 were retrospectively retrieved from electronic medical records and analyzed. SM respiratory infection was defined as SM isolated from sputum, endotracheal suction, or bronchial alveolar lavage plus acute respiratory symptoms. Between PH and non-PH groups, clinical characteristics and laboratory parameters were collected and compared. The newly developed platelet dissimilarity index (d-index) was calculated by accumulating differences between the actual and the lowest normal level of the platelet count in each patient at different time points. Within 1,039 patients with positive SM culture, 437 cases matched the criteria and were analyzed. A total of 125 (28.6%) patients developed PH and 312 (71.4%) did not. The patients with PH had increased prothrombin time/international normalized ratio (PT/INR), lower platelet count, and higher platelet d-index. Multivariate analysis revealed that extreme thrombocytopenia (platelet count &lt;50 × 103/μL) is a common independent risk factor in PH and mortality. The performance of platelet deficit and d-index varied between patients with different comorbidities. Performance of platelet deficit to predict PH is better in patients with hematology/oncology or liver disease (area under curve, 0.705–0.757), while d-index is better in patients with sepsis/treatment and various other groups (0.711–0.816). Prolonged and extreme thrombocytopenia is a determinant risk factor in PH in patients with SM respiratory infection. Given the complexity of causes of thrombocytopenia and associated comorbidities, different strategies should be applied when assessing the risk for PH.

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.

Invasive Fungal Disease in Patients with Newly Diagnosed Acute Myeloid Leukemia

This single-center retrospective study of invasive fungal disease (IFD) enrolled 251 adult patients undergoing induction chemotherapy for newly diagnosed acute myeloid leukemia (AML) from 2014–2019. Patients had primary AML (n = 148, 59%); antecedent myelodysplastic syndrome (n = 76, 30%), or secondary AML (n = 27, 11%). Seventy-five patients (30%) received an allogeneic hematopoietic cell transplant within the first year after induction chemotherapy. Proven/probable IFD occurred in 17 patients (7%). Twelve of the 17 (71%) were mold infections, including aspergillosis (n = 6), fusariosis (n = 3), and mucomycosis (n = 3). Eight breakthrough IFD (B-IFD), seven of which were due to molds, occurred in patients taking antifungal prophylaxis. Patients with proven/probable IFD had a significantly greater number of cumulative neutropenic days than those without an IFD, HR = 1.038 (95% CI 1.018–1.059), p = 0.0001. By cause-specific proportional hazards regression, the risk for IFD increased by 3.8% for each day of neutropenia per 100 days of follow up. Relapsed/refractory AML significantly increased the risk for IFD, HR = 7.562 (2.585–22.123), p = 0.0002, and Kaplan-Meier analysis showed significantly higher mortality at 1 year in patients who developed a proven/probable IFD, p = 0.02. IFD remains an important problem among patients with AML despite the use of antifungal prophylaxis, and development of IFD is associated with increased mortality in these patients.

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.