Significance of Aspergillemia in Patients with Cancer: A 10-Year Study

Abstract

The significance of blood cultures positive for Aspergillus species for patients with cancer remains unclear. The significance of aspergillemia in 36 cancer patients over a 10-year period was evaluated. True aspergillemia was rare, occurred late in the course of aspergillosis, and was seen exclusively in patients with hematologic malignancies.

Clinical significance of non‐Candida fungal blood isolation in patients undergoing high‐risk allogeneic hematopoietic stem cell transplantation (1993–2001)

“…In concert with our observation, aspergillemia in patients with cancer who did not undergo hematopoietic stem cell transplantation seldom was observed as "clinically significant" or "definite" hematogenous mycosis. 3,4 Similar to the current study ( Table 2), other studies have shown that the presence of non-Candida fungal blood isolates in most transplantation recipients with profound immunosuppression most likely represents contamination from an environmental source, suggesting "clinically nonsignificant fungemia" or "pseudofungemia." 1,2 In a retrospective analysis of Aspergillus species fungemia in patients with cancer, nearly 20% of all Aspergillus species-positive blood cultures were reported as representing "definite" mycoses; however, using the existing guidelines, 86% of those diagnoses could be established on postmortem examination only.…”

“…1,2 In a retrospective analysis of Aspergillus species fungemia in patients with cancer, nearly 20% of all Aspergillus species-positive blood cultures were reported as representing "definite" mycoses; however, using the existing guidelines, 86% of those diagnoses could be established on postmortem examination only. 3 This inadequacy of positive and negative predictive values of the existing diagnostic tests raises serious concerns regarding the limitations of the existing parameters for diagnosing "clinically significant" bloodstream invasion due to low-virulence, saprophytic, environmental molds. 2,4 Patients with hematologic malignancies, 3,14 recipients of hematopoietic stem cell transplantation, and patients receiving cytotoxic therapy for posttransplantation complications, such as GVHD, are at increased risk for disseminated fungal infections of non-Candida organisms.…”

“…3 This inadequacy of positive and negative predictive values of the existing diagnostic tests raises serious concerns regarding the limitations of the existing parameters for diagnosing "clinically significant" bloodstream invasion due to low-virulence, saprophytic, environmental molds. 2,4 Patients with hematologic malignancies, 3,14 recipients of hematopoietic stem cell transplantation, and patients receiving cytotoxic therapy for posttransplantation complications, such as GVHD, are at increased risk for disseminated fungal infections of non-Candida organisms. [15][16][17] Traditionally, most systemic fungal infections have been observed during the early allogeneic stem cell transplantation period (Ͻ 180 days after the transplantation), although, in patients with prolonged, severe immune dysfunction due to chronic GVHD therapy, late reactivation of human cytomegalovirus, etc., invasive mycoses may be encountered Ͼ 360 days after transplantation.…”

“…[15][16][17] Traditionally, most systemic fungal infections have been observed during the early allogeneic stem cell transplantation period (Ͻ 180 days after the transplantation), although, in patients with prolonged, severe immune dysfunction due to chronic GVHD therapy, late reactivation of human cytomegalovirus, etc., invasive mycoses may be encountered Ͼ 360 days after transplantation. 18 Because of the risk of serious hemorrhage in patients with low platelet counts (Ͻ 50,000 cells/ L), histologic examinations of the involved or infected organ are often deferred 3,4,19 ; this problem is highlighted by the paucity of antemortem diagnoses of definite invasive mycoses and the fact that most definite invasive fungal infections diagnosed with current criteria are reported in patients only after death. 3,10,20 Fortunately, in the current study, the fungemia-associated attributable mortality (15%) was found to be low among neutropenic allogeneic stem cell transplantation recipients who did not receive antifungal therapy and suggests that most fungal blood isolates (85%), even in a highly susceptible group, were "clinically nonsignificant" and most likely represented environmental contamination (Table 2).…”

“…4 Pseudofungemia was defined as the presence of a non-Candida fungal species isolated from the blood culture of a patient with a clinical illness due to another known pathogen, with features inconsistent with systemic mycoses, or with both. 3,4 All positive blood cultures obtained during the same hospitalization were considered a single episode; if more than one species was isolated, then each was regarded as a separate episode. Attributable mortality was defined as death within 30 days of the last positive fungal blood culture and in the absence of a known terminal event, such as intracranial or severe gastrointestinal hemorrhage, pulmonary embolism, myocardial infarction, pneumonitis due to human cytomegalovirus, bacterial septic shock, adult respiratory distress syndrome, or progressive graft-versushost disease (GVHD).…”