Bayesian estimation of post-test probability of Candida glabrata fungemia by means of serum creatinine.

Fungemia is a life-threatening condition associated with high mortality; the most frequently isolated genus is Candida. Candida glabrata is of particular concern because of its increasing resistance to azoles. We evaluated common lab tests accessible by almost all healthcare professionals to estimate the post-test probability of recovery of C. glabrata from a blood culture collected by venipuncture, positive for fungi identified by microscopic examination. Patients with blood cultures positive for C. glabrata had significantly higher median values of serum creatinine (P=0.006), and a value of ≥1.45 mg/dL was the best cut-off in discriminating C. glabrata from other Candida spp., with 0.67 [95% Confidence Interval (CI): 0.49-0.85] sensitivity and 0.75 (95% CI: 0.66-0.84) specificity; Youden's J statistic: 0.42. The receiver operator characteristic curve analysis showed an area under the curve of 0.718 (95% CI: 0.603-0.833); P=0.001. Therefore, given a pre-test probability of 24% and applying the Bayes' theorem, the post-test probability of C. glabrata fungemia with creatinine values ≥1.45 mg/dL increased to 45.8%. In conclusion, we showed how the probability of recovery of C. glabrata from blood cultures collected by venipuncture and positive for fungi can be better estimated using concurrent creatinine values.

Hematopoietic Stem Cells (HSC) and Granulocyte Macrophage Progenitors (GMP) are the Oxidative Stress Targets in Low/Intermediate-1 Risk Myelodysplastic Syndromes.

Introduction: Myelodysplastic Syndromes (MDS) are a heterogenous group of clonal hematopoietic stem cell malignancies. Previous studies showed that Reactive Oxygen Species (ROS) play a role in the pathogenesis and clinical evolution of MDS, contributing to Hematopoietic Stem and Progenitor Cells (HSPC) genetic instability. Less is known about ROS levels in the various sub-populations of MDS HSPC and how they correlate with clinical data in MDS patients. Our study aims to analyze ROS levels in MDS Hematopoietic Stem Cells (HSC), common myeloid progenitors (CMP), Granulocyte Macrophages Progenitors (GMP) and megakaryocyte-erythrocyte progenitors (MEP); afterwards, we looked at the relationship between ROS levels and clinical data. Methods: thirty-eight MDS and 27 Normal Bone Marrow (NBM) samples were collected; ROS levels were analyzed via multicolor flow cytometry. Results: In both NBM and MDS, HSC showed much higher ROS levels than progenitors (3 to 4 folds, p < 0.0001); HSC ROS were significantly more elevated in MDS-no excess blasts versus MDS with excess blasts and versus NBM. GMP from MDS-no excess blasts showed higher ROS compared to NBM GMP. The 3 MDS with Ringed Sideroblasts (RS) showed more elevated ROS in HSC and GMP compared to the not RS low/intermediate-1 MDS; the 2 monosomy 7 patients displayed higher ROS levels in each subpopulation compared to the normal karyotype MDS; the only del(5q) patient did not show relevant differences in ROS levels compared to the median of the normal karyotype MDS ROS. The 9 high transfusion burden patients exhibited higher ROS in HSC and GMP compared to NBM HSC and GMP. These data were not confirmed in low transfusion burden (n:2) and non-transfused patients (n:26). In low/intermediate-1 MDS, a direct correlation between ferritin values and ROS levels in progenitors, but not in HSC, was detected. Interestingly, low/intermediate-1 risk patients that are no longer responding to recombinant human erythropoietin (rh-EPO) showed higher ROS levels in GMP and HSC. Conclusions: Our data showed that ROS can play a role in the pathogenesis and maintenance of low and intermediate-1 risk MDS clone; ROS status can be influenced by several clinical factors as ferritin levels and rh-EPO treatment. In this scenario, high ROS levels can contribute to genetic instability and influence progression to AML. Further biological studies are needed to elucidate ROS role in MDS pathogenesis and analyze the possible benefit of antioxidant drugs added to the standard MDS treatments.

Health technology assessment-based approach to flow cytometric immunophenotyping of acute leukemias: a literature classification.

OBJECTIVE: Acute leukemia (AL) is a broad, heterogeneous group of malignant diseases. The diagnostic workup of AL is based on several clinical and laboratory findings, including flow cytometric immunophenotyping. However, the role of this assay in the diagnosis of AL has not been systematically investigated. The aim of this study was to determine the accuracy and utility of flow cytometric immunophenotyping in the identification, characterization, and staging of AL. METHODS: We performed a systematic selection and classification of the literature since 1980, focused on flow cytometric immunophenotyping of AL. We applied a 6-variables model to cover both the technical capabilities and the clinical value of flow cytometric immunophenotyping in the diagnosis of AL. RESULTS: Using 3 key words (acute leukemia, immunophenotyping, flow cytometry), we screened the literature from January 1985 to April 2015 in PubMed and Embase databases and found 1010 articles. A total of 363 were selected and submitted to the expert panel, which selected a final data set of 248 articles to be analyzed. Of these, 160 were focused on clinical and biological issues, 55 were technical articles, and 31 were reviews. These 248 articles were then analyzed according to the 6-variables model and definitively classified. CONCLUSIONS: We assessed the literature on flow cytometric immunophenotyping of AL over 3 decades as the first step toward an evidence-based analysis of the impact of this technology on the clinical management of patients with AL.

Diagnostic accuracy of a commercial multiplex PCR for the diagnosis of meningitis and encephalitis in an Italian general hospital.

Infectious meningitis and encephalitis are potentially life-threatening conditions caused mostly by bacterial and viral agents. Rapid diagnosis and prompt treatment are associated with a more favorable outcome. In recent years nucleic acid amplification tests have been developed to speed detection and identification of pathogens directly from cerebrospinal fluid (CSF). The aim of this study was to compare the diagnostic accuracy of a commercially available multiplex PCR assay for etiological diagnosis of infectious meningitis directly from CSF samples with culture. A secondary endpoint was to look for a possible screening threshold based on main CSF indices and urgent blood test results, to define CSF samples with low pre-test probability of PCR and/or culture-positive result. We performed a secondary analysis of results of CSF samples already processed as part of routine clinical care from February 2016 to December 2018. In all, 109 CSF samples were included in the study and a total of 14 bacteria were identified by either PCR, culture or both methods, along with nine samples positive for viruses. The comparison of PCR results with culture showed no significant difference: 7/109 (6.4%) vs 13/109 (11.9%) respectively, p=0.07. After exclusion of the isolates not detectable by the multiplex PCR panel, the diagnostic accuracy was: 100% (95% confidence interval (CI): 54.1% to 100%) sensitivity; 98.9% (95% CI: 93.5% to 99.9%) specificity; 85.7% (95% CI: 42% to 99.2%) positive predictive value; 100% (95% CI: 95.1% to 100%) negative predictive value; 96 (95% CI: 13.6 to 674.6) LR+; Zero LR-; Cohen's kappa: 0.918, p<0.0001. CSF protein value ≤ 28 mg/dl and CSF glucose/blood glucose ratio ≥0.78 were associated with both PCR-negative result for bacteria or viruses and culture-negative result. The multiplex PCR evaluated in this study showed a very good diagnostic performance compared to culture, and the thresholds found can be a useful tool to best choose which samples to test.

Features, reason for testing, and changes with time of 583 paroxysmal nocturnal hemoglobinuria clones from 529 patients: a multicenter Italian study.

In this study, we aimed at disclosing the main features of paroxysmal nocturnal hemoglobinuria (PNH) clones, their association with presentation syndromes, and their changes during follow-up. A large-scale, cooperative collection (583 clones from 529 patients) of flow cytometric and clinical data was entered into a national repository. Reason for testing guidelines were provided to the 41 participating laboratories, which followed the 2010 technical recommendations for PNH testing by Borowitz. Subsequently, the 30 second-level laboratories adopted the 2012 guidelines for high-resolution PNH testing, both upon order by the local clinicians and as an independent laboratory initiative in selected cases. Type3 and Type2 PNH clones (total and partial absence of glycosyl-phosphatidyl-inositol-anchor, respectively) were simultaneously present in 54 patients. In these patients, Type3 component was sevenfold larger than Type2 (p < 0.001). Frequency distribution analysis of solitary Type3 clone size (N = 442) evidenced two discrete patterns: small (20% of peripheral neutrophils) and large (> 70%) clones. The first pattern was significantly associated with bone marrow failure and myelodysplastic syndromes, the second one with hemolysis, hemoglobinuria, and thrombosis. Pediatric patients (N = 34) showed significant preponderance of small clones and bone marrow failure. The majority of PNH clones involved neutrophils, monocytes, and erythrocytes. Nevertheless, we found clones made exclusively by white cells (N = 13) or erythrocytes (N = 3). Rare cases showed clonal white cells restricted only to monocytes (6 cases) or neutrophils (3 cases). Retesting over 1-year follow-up in 151 cases showed a marked clone size increase in 4 cases and a decrease in 13, demonstrating that early breaking-down of PNH clones is not a rare event (8.6% of cases). This collaborative nationwide study demonstrates a clear-cut difference in size between Type2 and Type3 clones, emphasizes the existence of just two classes of PNH presentations based on Type3 clone size, depicts an asymmetric cellular composition of PNH clones, and documents the possible occurrence of changes in clone size during the follow-up.

Aberrant expression of CD8 in B-cell non-Hodgkin lymphoma: a multicenter study of 951 bone marrow samples with lymphomatous infiltration.

T-cell antigen expression can be observed in B-cell non-Hodgkin lymphoma (B-NHL). Although CD5 is expressed in B-cell chronic lymphocytic leukemia (B-CLL) and mantle cell lymphoma, the presence of other T-cell antigens is less common. This article reports a retrospective multicenter analysis in which flow cytometry was used to evaluate aberrant CD8 expression on the pathologic B cells of 951 bone marrow samples from patients with various types of B-NHL. In a total of 18 patients, CD8 was coexpressed: 10 had B-CLL; 1, small lymphocytic lymphoma (SLL); 1, marginal zone lymphoma; 1, lymphoplasmacytic lymphoma; 2, diffuse large B-cell lymphoma; and 3, follicular lymphoma. There was a 1.89% overall frequency of CD8 coexpression in which B-CLL/SLL had a higher frequency (3.03%) than did the other B-cell neoplasms (1.18%). Most cases were characterized by a favorable outcome.