ABSTRACT
BRAF V600E mutations are present in virtually all cases of hairy cell leukemia (HCL). We hypothesized that detection of phospho-ERK (pERK) in tissue sections may be a useful marker for diagnosis of HCL. pERK/CD20 double immunostaining was performed on 90 formalin-fixed bone marrow trephine samples affected with small B-cell lymphoproliferative disorders, including 28 cases of HCL. pERK staining was observed in all 28 cases of HCL and in 1 of 62 cases of non-HCL B-cell lymphoproliferative disorders. By allele-specific polymerase chain reaction, all 11 cases of HCL with available DNA were positive for BRAF V600E, as was the 1 pERK non-HCL case. The remaining 31 non-HCL cases tested were negative for BRAF V600E. The sensitivity and specificity of pERK for diagnosis of HCL was 100% and 98%, respectively. We conclude that the presence of pERK as detected by immunohistochemical staining is a useful surrogate marker for BRAF V600E in the diagnosis of HCL.
Subject(s)
Biomarkers, Tumor/metabolism , Extracellular Signal-Regulated MAP Kinases/metabolism , Leukemia, Hairy Cell/diagnosis , Leukemia, Hairy Cell/enzymology , Bone Marrow Cells/metabolism , Bone Marrow Cells/pathology , Bone Marrow Examination/methods , Cell Line, Tumor , DNA, Neoplasm/analysis , Diagnosis, Differential , Humans , Phosphorylation , Point Mutation , Proto-Oncogene Proteins B-raf/genetics , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
INTRODUCTION: Candida lusitaniae was originally described as a human pathogen in 1979 and typically affects immunocompromised patients. CASE PRESENTATION: We describe a case of prosthetic valve endocarditis with Candida lusitaniae in an immunocompetent 62-year-old woman following aortic valve replacement. In vitro testing demonstrated that our isolate was sensitive to amphotericin B, caspofungin and fluconazole. CONCLUSION: The infection was lethal despite aggressive medical and surgical management and sterilization of blood cultures. The outcome of our case illustrates the need to recognize Candida lusitaniae fungemia as a life-threatening infection in a patient with a prosthetic aortic valve.
