galactomannan and Pneumonia--Pneumocystis

Both 1,3-beta-D-glucan (BDG) and galactomannan (GM) are polysaccharide components of the fungal cell wall. Although elevated levels of serum BDG and Aspergillus GM suggest invasive fungal infection or Pneumocystis pneumonia and aspergillosis, respectively, it is also necessary to consider the possibility of false-positives. We herein report a 68-year-old man with marked elevation in serum BDG and GM levels accompanied by Mendelson's syndrome after rice aspiration. With the improvement of Mendelson's syndrome, his serum BDG and GM levels decreased. The false-positive serum BDG and GM findings may have been due to his aspiration of food containing them. It is important to take a detailed history of aspiration in addition to making a conventional differential diagnosis in patients with pneumonia with elevated serum BDG and GM levels.

Topics: Aged; Aspergillus; beta-Glucans; Galactose; Glucans; Humans; Male; Mannans; Oryza; Pneumonia, Aspiration; Pneumonia, Pneumocystis; Sensitivity and Specificity

The present study aims to evaluate the diagnostic yield of bronchoalveolar lavage (BAL) fluid in patients with hematological malignancies and describe the most common pathogens detected in BAL fluid (BALF.) An analysis of 480 BALF samples was performed in patients with hematological malignancies over a period of 7 years. The results of culture methods, PCR, and immunoenzymatic sandwich microplate assays for Aspergillus galactomannan (GM) in BALF were analyzed. Further, the diagnostic thresholds for Aspergillus GM and Pneumocystis jiroveci were also calculated. Microbiological findings were present in 87% of BALF samples. Possible infectious pathogens were detected in 55% of cases; 32% were classified as colonizing. No significant difference in diagnostic yield or pathogen spectrum was found between non-neutropenic and neutropenic patients. There was one significant difference in BALF findings among intensive care units (ICU) versus non-ICU patients for Aspergillus spp. (22% versus 9%, p = 0.03). The most common pathogens were Aspergillus spp. (n = 86, 33% of BAL with causative pathogens) and Streptococcus pneumoniae (n = 46, 18%); polymicrobial etiology was documented in 20% of cases. A quantitative PCR value of > 1860 cp/mL for Pneumocystis jirovecii was set as a diagnostic threshold for pneumocystis pneumonia. The absorbance index of GM in BALF of 0.5 was set as a diagnostic threshold for aspergillosis. The examination of BAL fluid revealed the presence of pathogen in more than 50% of cases and is, therefore, highly useful in this regard when concerning pulmonary infiltrates.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Aspergillus; Bronchoalveolar Lavage Fluid; DNA, Fungal; Female; Galactose; Hematologic Neoplasms; Humans; Intensive Care Units; Male; Mannans; Middle Aged; Neutropenia; Pneumocystis carinii; Pneumonia, Pneumocystis; Retrospective Studies; Streptococcus pneumoniae; Young Adult

To investigate the utility of beta-D-glucan (BDG) testing in bronchoalveolar lavage (BAL) fluid for the diagnosis of invasive fungal infection (IFI), as compared to BAL galactomannan (GM).. We retrospectively reviewed medical records of 132 consecutive patients at the National Institutes of Health (NIH) in whom BAL BDG testing was performed for diagnosis of pneumonia. Using the European Organization for Research and Treatment of Cancer/Mycoses Study Group guidelines, we determined which patients had proven or probable IFI, and assessed the diagnostic performance of BAL BDG testing, relative to BAL GM. We also determined the reproducibility of the BDG assay in BAL via repeat testing of patient samples.. Ten patients had Pneumocystis pneumonia, and 34 patients had proven/probable IFI, including 14 with invasive aspergillosis (IA). BAL BDG was 100% sensitive for Pneumocystis. Although BAL BDG had similar sensitivity to BAL GM for the diagnosis of IA and IFI, it exhibited inferior specificity. Repeat testing demonstrated poor reproducibility of the BDG assay in BAL but not in serum.. BDG testing exhibits poor specificity and reproducibility in BAL. Identification of the BAL-specific factors that may interfere with the performance of the assay could improve the clinical usefulness of BAL BDG testing.

Topics: beta-Glucans; Bronchoalveolar Lavage Fluid; Female; Fusariosis; Galactose; Humans; Invasive Pulmonary Aspergillosis; Lung Diseases, Fungal; Male; Mannans; Mucormycosis; Paecilomyces; Pneumonia, Pneumocystis; Reproducibility of Results; Retrospective Studies; Scopulariopsis; Sensitivity and Specificity

Invasive aspergillosis is a major cause of morbidity and mortality in immunocompromised patients receiving intensive care. The double-sandwich ELISA for galactomannan is reported to have a high sensitivity (96.5%) for the detection of invasive aspergillosis when a cut-off value of 0.8 ng/ml is used. However, we have experienced a case of lethal disseminated aspergillosis in a patient that presented with a negative galactomannan (GM) test and persistent elevation of beta-D glucan (BG) levels. A 63-year-old female was admitted to our Intensive Care Unit (ICU) in acute respiratory failure and elevated BG. She had been receiving medication for Good-pasture syndrome based on anti-glomerular basement membrane antibodies and myeloperoxidase-antineutrophil cytoplasmic antibodies for 9 months and was receiving long-term prednisolone therapy (20 mg/day). On admission, her trachea was immediately intubated, and a PCR analysis of the bronchoalveolar lavage sample revealed Pneumocystis jiroveci. Trimethoprimsulfamethoxazole therapy was started for Pneumocystis pneumonia. The levels of BG remained elevated (> 100 pg/ml) during the treatment period despite the clinical resolution of Pneumocystis pneumonia, raising concerns of another complicated invasive fungal disease; consequently, fosfluconazole was administered empirically. The serum BG levels, however, did not decrease. Blood cultures did not detect a fungal infection. Serum GM levels measured by a double-sandwich ELISA on the 6th, 11th, and 24th days in the ICU were negative (< 0.2 ng/ml). The patient ultimately died of multiple organ failure on the 45th ICU day. Postmortem examination revealed a disseminated fungal infection with aggressive vascular invasion of the lungs, heart, and brain. In situ hybridization with a 568-bp probe of the alkaline proteinase sequence of Aspergillus fumigatus showed specific positive staining within the fungus present in the infected lung tissue, revealing that this patient may have had a systemic infection by A. fumigatus or A. flavus. This is a case of serum GM-negative disseminated aspergillosis pathologically proven by autopsy. Persistent elevated BG levels (> 100 pg/ml) refractory to trimethoprim-sulfamethoxazole and fosfluconazole may suggest possible Aspergillus infection and should prompt the initiation of empiric anti-aspergillosis therapies in patients at risk for fungal infection.

Topics: Antifungal Agents; Aspergillosis; Aspergillus; beta-Glucans; Brain; Fatal Outcome; Female; Galactose; Heart; Humans; Immunosuppressive Agents; Intensive Care Units; Lung; Mannans; Middle Aged; Pneumocystis carinii; Pneumonia, Pneumocystis; Prednisolone; Trimethoprim, Sulfamethoxazole Drug Combination