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Key Clinical Message Nontuberculous mycobacteria infrequently cause disseminated infections in immunocompetent hosts. However, they are increasingly being recognized in immunocompromised patients. We present the case of a 40-year-old HIV-positive male presenting with lymphadenopathies and pancytopenia in whom disseminated infection, with bone marrow involvement by Mycobacterium genavense ( M. genavense) was diagnosed. [ABSTRACT FROM AUTHOR]

Background: Laparoscopic splenectomy (LS) is considered the standard treatment for patients with refractory primary immune thrombocytopenia (ITP). Patients and Methods: All patients with ITP who underwent LS during the last 17 years and who had a minimum follow-up of 1 year were included. Several perioperative variables such as age, platelet count, and duration of preoperative therapy were recorded and analyzed, looking for potential predictive variables of clinical response. Results: In total, 150 patients were included: 108 (72%) women and 42 (28%) men, with a mean age of 37.3±15.8 years. In the evaluation 1 year after surgery, 133 (88.7%) patients had achieved complete response, 4 (2.7%) had a response, and in 13 (8.6%) there was no response. None of the analyzed preoperative variables was identified as a predictive factor of response at 1 year. Immediate responders after surgery (≥150,000 platelets/mL during the first week) had a higher platelet count and rate of complete response at 1 year (94.2%). Conclusions: LS has a high success rate in patients with refractory ITP. Potential predictive indicators of success remain to be determined. [ABSTRACT FROM AUTHOR]

High P-glycoprotein-mediated multidrug resistance-1 (P-gp/MDR1) activity in lymphocytes from idiopathic thrombocytopenic purpura (ITP) patients may affect disease outcome. ITP treatment includes glucocorticoids that are substrates of P-gp; hence, P-gp functional activity and antigenic expression were assessed by flow cytometry in T and natural killer (NK) cells from ITP patients before and after prednisone therapy. Herein, patients’ T and NK cells did not show increased MDR1 functional activity, whereas P-gp antigenic expression was significantly enhanced in both therapy-free and prednisone-treated patients. Prednisone treatment did not significantly modify the function and expression of MDR1 in T and NK cells of ITP patients. [Copyright &y& Elsevier]

Objective. P-glycoprotein (P-gp) expression has been widely observed in normal and neoplastic cells. The physiologic role of P-gp involves hormone and metabolite secretion, bacterial product detoxification, and transport of several drugs to the extracellular space. Multidrug resistance-1 is characterized by drug extrusion through P-gp, reducing the intracellular levels of drugs and diminishing their pharmacological effects. Treatment of immune thrombocytopenic purpura (ITP) includes agents that are substrates of P-gp; hence, the objective of this study was to analyze the functional activity of P-gp in lymphocytes from patients with ITP.Patients and Methods. 30 ITP patients (9 refractory, 5 dependent, 14 responders to treatment, and 2 with stable disease) and 25 healthy controls were studied. Peripheral blood mononuclear cells were isolated by gradient centrifugation and incubated with daunorubicin (a fluorescent drug extruded by P-gp). Functional activity of P-gp was analyzed by flow cytometry. Results were expressed as the percentage of lymphocytes able to extrude daunorubicin.Results. ITP patients showed an increased number of lymphocytes with P-gp activity (mean = 12.3%±16%) when compared to controls (mean = 0.87%±0.72%) (p<0.05). P-gp function was higher in the refractory group (median = 9.4%) than in the treatment-dependent (median = 5.4%), responder (median = 6.4%), and stable disease (median = 5.2%) groups, although no statistical differences were found among them.Conclusion. Enhanced P-gp activity in ITP may be related to an unfavorable clinical outcome and poor response to treatment. Furthermore, P-gp function might affect therapeutic requirements for disease control. [Copyright &y& Elsevier]

The correct classification of acute leukemias (AL) is an essential part in the evaluation of any patient with this disease. Historically, CD117 has been an important asset in the diagnosis of patients with mixed-phenotype acute leukemia (MPAL). In an attempt to simplify the diagnosis of MPAL with fewer and more lineage specific markers, the World Health Organization (WHO) proposed in 2008 a new criteria for the diagnosis of this type of AL, which excluded CD117 from the myeloid markers that are utilized to diagnose MPAL. In order to assess whether CD117 is necessary in the diagnosis of MPAL, we evaluated the sensitivity and specificity of CD117 for acute myeloid leukemia (AML) in 331 patients with AL. The calculated sensitivity of CD117 for AML was 85.88% (103/120), while the specificity was 83.9% (177/211). Besides myeloperoxidase (MPO), which was used as the gold standard in differentiating AML from other type of ALs, the most specific markers for AML in our study were CD14 and CD64 (99.5 and 95.6%). Although the specificity of CD117 in this study is not as high as CD14 and CD64, markers concomitantly used in this this study and in the WHO classification, based on the results of other researches (i.e. the specificity of CD117 for AML was 100% in one study) and due to the fact that its specificity for AML in this study is relatively high, we recommend the use CD117 in assigning a myeloid lineage in MPAL. [ABSTRACT FROM AUTHOR]

: BackgroundDifferent flow cytometric methods have been developed to derive absolute CD34+ cells in predicting transplant outcome. Two techniques for preparing cells for quantification of CD34+ cells were compared.: MethodsEnumeration of CD34+ cells in 16 samples of bone marrow (BM) and in 29 samples of mobilized peripheral blood stem cells (PBSC) obtained by leukapheresis was assessed simultaneously by single-platform (ProCOUNT kit) and dual-platform (Milan protocol) approaches within the first 3 h of collection.: ResultsAbsolute number of CD34+ cells obtained in PBSC and BM using single- and dual-platform methods showed high determination coefficients as follows: for PBSC, slope = 1.0515 ± 0.048, y-intercept = 88.638 ± 52.45, and r2 = 0.941, and for BM, slope = 1.0203 ± 0.093, y-intercept = 122.25 ± 20.65, and r2 = 0.878. There were no statistically significant differences in absolute number of CD34+ cells from PBSC between single-platform (mean 575/μL, range 70–3,683/μL) and dual-platform (786/μL, range 51–3,804/μL) assays. In contrast, absolute number of CD34+ cells from BM was significantly lower (p = 0.0002) when enumerated by ProCount kit (135/μL, 14–758/μL) than with dual-platform method (260/μL, 74–889/μL).: ConclusionsBoth approaches can be used indistinctly to estimate absolute number of CD34+ cells in PBSC but not in BM. [Copyright &y& Elsevier]

Background: In Mexico, the frequency of thromboembolic events associated to paroxysmal nocturnal hemoglobinuria is 3%; a clone size > 50% in granulocytes has been associated with a higher risk of thromboembolic events., Methods: Between 2001 and 2012, 40 patients with paroxysmal nocturnal hemoglobinuria were studied. In 12 cases anticoagulant, procoagulant, and fibrinolytic pathways were analyzed., Results: Only two of 40 patients (5%) developed a thromboembolic event over a 25.5-year follow-up period. From 12 patients, 91.7% had a paroxysmal nocturnal hemoglobinuria clone > 50% in granulocytes and 83.3% a clone > 50 % in monocytes. Five of 12 cases had elevated FV levels and four showed increased FVIII, von Willebrand factor antigen, von Willebrand factor ristocetin cofactor activity and FX. Protein S and protein C were decreased in nine and three patients, respectively. Only antithrombin correlated positively with paroxysmal nocturnal hemoglobinuria clone size in monocytes (p = 0.0442), whereas von Willebrand factor ristocetin cofactor correlated negatively with lactic dehydrogenase levels (p = 0.0186). No statistically significant associations were recorded with all other factors., Conclusion: The low frequency of thromboembolic events in Mexican patients could partly be explained by the associations between anticoagulant system (antithrombin) with paroxysmal nocturnal hemoglobinuria monocyte clone size, and procoagulant system (von Willebrand factor ristocetin cofactor) with lactic dehydrogenase levels.