1820. A Critical Reappraisal of Prolonged Neutropenia as a Risk factor for Invasive Pulmonary Aspergillosis
Session: Poster Abstract Session: Respiratory Infections: Potpourri
Saturday, October 10, 2015
Room: Poster Hall

Background: There is an extensive scientific literature that supports the view that prolonged neutropenia is an important risk factor for invasive pulmonary aspergillosis (IPA). Our goal was to re-explore this established view and determine the frequency, severity and duration of neutropenia that immediately precedes the diagnosis of IPA.

Methods: Patients hospitalized at Massachusetts General Hospital or Brigham and Women's Hospital from 2004-2014 were retrospectively identified. Patients were included if EORTC criteria for probable or proven IPA were met and a peripheral blood absolute neutrophil count (ANC) was drawn within 7 days prior to IPA diagnosis. Neutropenia was defined as ANC<500 and was categorized as prolonged if present for >7 days consecutively. Profound neutropenia was defined as ANC<50. Patients were classified into the following categories of immunosuppression: hematologic malignancy or bone marrow transplant (HM/BMT), solid organ transplant (SOT), or Others.

Results: In total, 315 patients were included. 187 HM/BMT, 42 SOT, and 86 Others. Neutropenia preceded IPA in 138 (43.8%) patients and was significantly more common in the HM/BMT (67.4%) cohort compared to SOT (14.3%, P<.01) or Others (7.0%, P<.01). The proportion of neutropenic episodes categorized as prolonged and/or profound was significantly higher in the HM/BMT (97.6%) cohort compared to SOT (66.7%, P=.03) or Others (50.0%, P<.01).

Conclusion: Neutropenia preceded IPA in fewer than half of the cases. The vast majority of neutropenic episodes occurred in the HM/BMT cohort. In these cases, neutropenia was nearly always prolonged and/or profound. The absence of neutropenia should not dissuade the clinician from considering the diagnosis of IPA, especially in non-HM/BMT populations.

Table 1. Duration and Severity of Neutropenia that Precedes IPA

Description of Neutropenia

All

(n=315)

HM/BMT

(n=187)

SOT

(n=42)

Others

(n=86)

Neutropenic (any)*

138

(43.8%)

126

(67.4%)

6

(14.3%)

6

(7.0%)

Prolonged

116

(36.8%)

111

(59.4%)

2

(4.8%)

3

(3.5%)

Profound

118

(37.5%)

112

(59.9%)

3

(7.1%)

3

(3.5%)

Prolonged Profound

90

(28.6%)

86

(46.0%)

1

(2.4%)

3

(3.5%)

Prolonged and/or Profound

130

(41.3%)

123

(65.8%)

4

(9.5%)

3

(3.5%)

Figure 1. ANC at the Time of IPA Diagnosis

Michael Abers, MD, Mark Poznansky, MD, PhD, FIDSA and Jatin Vyas, MD, PhD, FIDSA, Massachusetts General Hospital, Harvard Medical School, Boston, MA

Disclosures:

M. Abers, None

M. Poznansky, None

J. Vyas, None

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