galactomannan and Anemia--Aplastic

Invasive aspergillosis has become the leading cause of death after allogeneic hematopoietic stem cell transplantation. This is partially due to the lack of a prompt diagnosis. Recently the detection of Aspergillus galactomannan antigen by means an ELISA technique in serum has been described. The objective of this study was to validate its usefulness in the allogeneic hematopoietic stem cell transplantation setting.

Topics: Adolescent; Adult; Amphotericin B; Anemia, Aplastic; Antifungal Agents; Antigens, Fungal; Aspergillosis; Aspergillus; Biomarkers; Enzyme-Linked Immunosorbent Assay; False Negative Reactions; Female; Fungemia; Galactose; Hematologic Neoplasms; Hematopoietic Stem Cell Transplantation; Humans; Immunocompromised Host; Male; Mannans; Middle Aged; Predictive Value of Tests; Prospective Studies; Transplantation Conditioning; Transplantation, Homologous

The double sandwich ELISA detecting Aspergillus galactomannan (GM) was prospectively evaluated for the diagnosis of invasive aspergillosis (IA) in 50 haematological patients at risk for IA. Serum samples were collected once weekly as long as the risk factors persisted. Six patients had proven or probable IA (3 A. fumigatus, 1 A. flavus, 1 A. niger, 1 A. ustus) and the GM titres were parallel to the clinical evolution of IA. Six of nine patients with suspected IA had at least two consecutive serum GM titres above 1 ng/ml and died with increasing titres, whereas the GM-negative patients survived. Positive GM titres did not anticipate the isolation of fungi. Unfortunately, positive GM titres did not anticipate the initiation of antifungal therapy, based on clinical suspicion. Moreover, if a true-positive result was defined as two consecutive positive serum samples, four patients out of 35 without proven, probable or suspected IA were positive. Then, the rate of false-positive results was high (12%) in the range previously reported. Nevertheless, the GM ELISA appears useful to assess IA and to follow the efficacy of antifungal treatment.

Topics: Adolescent; Adult; Aged; Anemia, Aplastic; Antigens, Fungal; Aspergillosis; Aspergillus; Bone Marrow Transplantation; Child; Enzyme-Linked Immunosorbent Assay; False Positive Reactions; Fatal Outcome; Female; Galactose; Humans; Leukemia; Male; Mannans; Middle Aged; Neutropenia; Prospective Studies

Screening for galactomannan (GM) has been adopted by many European centers as part of the management plan for allogeneic stem cell transplant recipients. However, the temporal onset of GM antigenemia remains unknown. A series of allogeneic stem cell transplant recipients were monitored prospectively, and the relationship between antigenemia and other diagnostic triggers for initiation of antifungal therapy was analyzed. GM detection had a sensitivity of 94.4% and a specificity of 98.8%. Positive and negative predictive values were 94.4% and 98.8%, respectively. This statistical profile was better than that of other triggers, including unexplained fever, new pulmonary infiltrates, isolation of Aspergillus species, and abnormalities seen on computed tomography. Antigenemia preceded diagnosis on the basis of radiologic examination or Aspergillus isolation by 8 and 9 days in 80% and 88.8% of patients, respectively. Antigenemia preceded therapy in 83.3% of patients. Detection of GM was especially useful when patients were receiving steroid treatment or when coexisting conditions masked the diagnosis of invasive aspergillosis. Prospective screening for GM allows earlier diagnosis of aspergillosis than do conventional diagnostic criteria.

Topics: Adolescent; Adult; Age Distribution; Anemia, Aplastic; Aspergillosis; Biomarkers; Female; Galactose; Hematologic Neoplasms; Humans; Male; Mannans; Middle Aged; Neoplasms; Stem Cell Transplantation; Survival Analysis; Time Factors; Transplantation, Homologous