Current issues in the clinical management of invasive aspergillosis--the AGIHO, DMykG, ÖGMM and PEG web-based survey and expert consensus conference 2009

Diagnostic work up to assess early response indicators in invasive pulmonary aspergillosis in adult patients with haematologic malignancies

In immunocompromised patients with acute leukaemia as well as in allogeneic hematopoietic stem cell transplant patients, pulmonary lesions are commonly seen. Existing guidelines provide useful algorithms for diagnostic procedures and treatment options, but they do not give recommendations on how to evaluate early success or failure and if or when it is best to change therapy. Here, we review the diagnostic techniques currently used in association with clinical findings and propose an approach using a combination of computer tomography, clinical and all available biomarkers and inflammation parameters, especially those positive at baseline, to assess early response in invasive pulmonary aspergillosis. Computed tomography scans should be carried out at regular intervals during early and long-term follow-up. Imaging on day seven, or even earlier in clinically unstable patients, combined with an additional testing of biomarkers and inflammatory markers in between, is needed for a reliable assessment at day 14. If no improvement is seen after 2 weeks of therapy or the clinical condition is deteriorating, a change of antifungal therapy should be considered. Alleged breakthrough infections or treatment failure should undergo early diagnostic workup, including tissue biopsies when possible, to retrieve fungal cultures for resistance testing.

Serial assessment of pulmonary lesion volume by computed tomography allows survival prediction in invasive pulmonary aspergillosis

BACKGROUND

Serial chest CT is the standard of care to establish treatment success in invasive pulmonary aspergillosis (IPA). Data are lacking how response should be defined.

METHODS

Digital CT images from a clinical trial on treatment of IPA were re-evaluated and compared with available biomarkers. Total volume of pneumonia was added up after manual measurement of each lesion, followed by statistical analysis.

RESULTS

One-hundred and ninety CT scans and 309 follow-up datasets from 40 patients were available for analysis. Thirty-one were neutropenic. Baseline galactomannan (OR 4.06, 95%CI: 1.08-15.31) and lesion volume (OR 3.14, 95%CI: 0.73-13.52) were predictive of death. Lesion volume at d7 and trend between d7 and d14 were strong predictors of death (OR 20.01, 95%CI: 1.42-282.00 and OR 15.97, 95%CI: 1.62-157.32) and treatment being rated as unsuccessful (OR 4.75, 95%CI: 0.94-24.05 and OR 40.69, 95%CI: 2.55-649.03), which was confirmed by a Cox proportional hazards model using time-dependent covariates.

CONCLUSION

Any increase in CT lesion volume between day 7 and day 14 was a sensitive marker of a lethal outcome (>50%), supporting a CT rescan each one and 2 weeks after initial detection of IPA. The predictive value exceeded all other biomarkers. Further CT follow-up after response at day 14 was of low additional value.

KEY POINTS

• CT evaluation offers good prediction of outcome for invasive pulmonary aspergillosis. • Predictive capability exceeds galactomannan, blood counts, and lesion count. • Any progression between day 7 and day 14 constitutes a high-risk scenario.

Impaired RASGRF1/ERK-mediated GM-CSF response characterizes CARD9 deficiency in French-Canadians

BACKGROUND

Caspase recruitment domain-containing protein 9 (CARD9) deficiency is an autosomal recessive primary immunodeficiency conferring human susceptibility to invasive fungal disease, including spontaneous central nervous system candidiasis (sCNSc). However, clinical characterization of sCNSc is variable, hindering its recognition. Furthermore, an in-depth understanding of the bases for this susceptibility has remained elusive.

OBJECTIVES

We sought to comprehensively characterize sCNSc and to dissect the mechanisms by which a hypomorphic CARD9 mutation causes susceptibility to Candida species.

METHODS

We describe the clinical and radiologic findings of sCNSc caused by CARD9 deficiency in a French-Canadian cohort. We performed genetic, cellular, and molecular analyses to further decipher its pathophysiology.

RESULTS

In our French-Canadian series (n = 4) sCNSc had onset in adulthood (median, 38 years) and was often misinterpreted radiologically as brain malignancies; 1 patient had additional novel features (eg, endophthalmitis and osteomyelitis). CARD9 deficiency resulted from a hypomorphic p.Y91H mutation and allelic imbalance established in this population through founder effects. We demonstrate a consistent cellular phenotype of impaired GM-CSF responses. The ability of CARD9 to complex with B-cell CLL/lymphoma 10 (BCL10) and mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) is intact in our series, arguing against its involvement in susceptibility to fungi. Instead, we show that the p.Y91H mutation impairs the ability of CARD9 to complex with Ras protein-specific guanine nucleotide-releasing factor 1 (RASGRF1), leading to impaired activation of nuclear factor κB and extracellular signal-regulated kinase (ERK) in monocytes and subsequent GM-CSF responses. Successful treatment of a second patient with adjunctive GM-CSF bolsters the clinical relevance of these findings.

CONCLUSIONS

Hypomorphic CARD9 deficiency caused by p.Y91H results in adult-onset disease with variable penetrance and expressivity. Our findings establish the CARD9/RASGRF1/ERK/GM-CSF axis as critical to the pathophysiology of sCNSc.

Laboratory diagnosis of invasive aspergillosis: from diagnosis to prediction of outcome

Invasive aspergillosis (IA), an infection caused by fungi in the genus Aspergillus, is seen in patients with immunological deficits, particularly acute leukaemia and stem cell transplantation, and has been associated with high rates of mortality in previous years. Diagnosing IA has long been problematic owing to the inability to culture the main causal agent A. fumigatus from blood. Microscopic examination and culture of respiratory tract specimens have lacked sensitivity, and biopsy tissue for histopathological examination is rarely obtainable. Thus, for many years there has been a great interest in nonculture-based techniques such as the detection of galactomannan, β -D-glucan, and DNA by PCR-based methods. Recent meta-analyses suggest that these approaches have broadly similar performance parameters in terms of sensitivity and specificity to diagnose IA. Improvements have been made in our understanding of the limitations of antigen assays and the standardisation of PCR-based DNA detection. Thus, in more recent years, the debate has focussed on how these assays can be incorporated into diagnostic strategies to maximise improvements in outcome whilst limiting unnecessary use of antifungal therapy. Furthermore, there is a current interest in applying these tests to monitor the effectiveness of therapy after diagnosis and predict clinical outcomes. The search for improved markers for the early and sensitive diagnosis of IA continues to be a challenge.

Aspergillus infection and extracorporeal membrane oxygenation support

BACKGROUND

The clinical characteristics of patients with Aspergillus isolation while supported on extracorporeal membrane oxygenator (ECMO) remain unclear.

OBJECTIVES

We present a case report of angioinvasive Aspergillus infection on an infant supported on ECMO and also investigate outcomes among patients with Aspergillus infection reported to the Extracorporeal Life Support Organization (ELSO) registry.

DESIGN

Case report and retrospective analysis of ELSO registry data set from 1985 to 2009.

SETTING

One hundred and seventy ECMO centers contributing data to the ELSO registry.

PATIENTS

Single case report and patients 0 to 90 years of age with Aspergillus infection requiring ECMO support as reported to the ELSO registry.

METHODS

Besides presenting details of our institutional case, we compared clinical characteristics and outcomes between pediatric and adult patients with Aspergillus isolation. Risk factors for in-hospital mortality were investigated. Kaplan-Meier estimates for freedom from death on ECMO for pediatric and adult patients were investigated.

MEASUREMENTS AND MAIN RESULTS

(a) we report a case with Aspergillus supported on ECMO, (b) the ELSO registry yielded 46 patients with 59% (n = 27) in the pediatric data set (≤20 years of age) and 41% (n = 19) in the adult data set (>20 years of age) with Aspergillus infection requiring ECMO support. Overall survival to hospital discharge was 30% (14/46) with 22% (6/27) in children as compared to 42% (8/18) in adults (P = .19). Table 1 shows a comparison of clinical characteristics between children and adults. The comparison between adults and pediatric groups differed significantly in age (P = .0001), more use of venoarterial ECMO in children (P = .028). The median age of pediatric group was 1.95 years (range 0-17.3 years) versus 30.2 years (range 22-60 years) among adults.

CONCLUSIONS

Aspergillus infection/colonization is associated with a 70% overall mortality among patients supported on ECMO. The ELSO registry data confirms that Aspergillus infection among ECMO supported patients occurs often in hosts who do not have known immunodeficiencies. The case stresses the need for a high level of suspicion for Aspergillus infection in nonimproving lung disease in patients on ECMO support.