Leukocyte Cell Population Data for Hematology Analyzer-Based Distinction of Clonal-versus-Non-Clonal Lymphocytosis: A Real-World Testing Experience

Automated blood counts revealing lymphocytosis necessitate smear reviews. Even expert morphological evaluation may however, fail to differentiate a benign-versus-malignant etiology without further testing. Automated analyser-derived quantitative data on leukocyte cell populations remain undertested for distinguishing such etiologies. Instrument manufacturers claim that if successful, they may be used to generate software flags that help under-resourced laboratories better triage hemogram specimens requiring further testing. We tested the diagnostic accuracy of volume-conductivity-scatter (VCS) indices together with complete blood count (CBC) parameters in such scenarios. We compared LH780-derived (Beckman Coulter, FL, USA) CBC + VCS parameters from patients with clonal lymphoproliferations (n = 42, including 30 chronic lymphocytic leukemia cases) versus 83 controls with absolute or relative lymphocytosis (derivation cohort). Diagnostic performances of 11 logistic regression equations derived were subsequently evaluated on two specific validation cohorts (n = 130 and n = 1465). Clonal lymphocytoses showed significantly lower hemoglobin and higher leukocyte counts but similar lymphocyte percentages (LY %) vis-à-vis controls. The most significant, albeit overlapping predictor of clonality was the absolute lymphocyte count, LY# (47.8 ± 48.4 × 10⁹/L vs. 2.9 ± 1.4 × 10⁹/L in clonal vs. benign cases). In eleven logistic regression equations constructed using four combinatorial approaches, only the models with LY# (highest sensitivity/specificity of 99.3%/100%) and the lymphocytic VCS parameters alone (highest sensitivity/specificity of 76.2%/90.2%) performed consistently in both validation cohorts. Lymphocytic VCS parameters were moderately successful in distinguishing benign-versus-malignant lymphocytes. Other approaches of CBC-plus-VCS parameters did not sustain their initial excellent performances in the validation cohorts, highlighting a need for careful appraisal and better standardization of automated cellular analysis technologies.     

Interferon‐Induced Protein with Tetratricopeptide Repeats 1 (IFIT1) as a Prognostic Marker for Local Control in T1‐2 N0 Breast Cancer Treated with Breast‐Conserving Surgery and Radiation Therapy (BCS + RT)

Interferon‐induced protein with tetratricopeptide repeats 1 (IFIT1) expression, involved in the regulation of translation, has been implicated to mediate resistance to chemotherapy and radiation in cancer cells in vitro. The purpose of this study was to evaluate the prognostic significance of IFIT1 protein expression in patients with breast cancer treated with Breast‐Conserving Surgery and Radiation Therapy (BCS + RT). A tissue microarray was constructed with specimens from 282 women with node‐negative, early‐stage (I/II) breast cancer who were treated with BCS + RT. Immunohistochemistry was used to stain for the IFIT1 protein. Cytoplasmic IFIT1 protein expression levels were correlated with clinicopathologic factors, local relapse‐free survival (LRFS), disease‐free survival (DFS), and overall survival (OS). IFIT1 positivity was found in 123 (49%) of cases. The median follow‐up time was 7.3 years. Eighty percent of the patients had T1 disease, 88% were human epidermal growth factor receptor 2 (HER2) negative, and 20% had triple‐negative breast cancer (TNBC). IFIT1 positivity was associated with estrogen receptor negative status (p = 0.002), progesterone receptor negative status (p = 0.02), TNBC (p = 0.01), and HER2‐positive status (p = 0.006). In univariate and multivariate analysis, IFIT1 positivity was associated with improved LRFS (p = 0.055 and p = 0.04, respectively). Using a log‐rank test, IFIT1 positivity was found to be associated with improved LRFS (94% versus 85%, p = 0.046) but not DFS or OS at 10 years. On subset analysis of the TNBC patients, IFIT1 positivity was found to correlate with improved LRFS (100% versus 53%, p = 0.004) and DFS in (87% versus 49%, p = 0.048) at 10 years. Elevated IFIT1 protein expression is associated with improved LRFS. In addition, our data suggest that IFIT1 expression may help risk stratify patients with TNBC who may benefit from more aggressive therapy. As there is limited data on IFIT1 in breast cancer, additional work is needed to ascertain its significance.     

A novel series of highly potent benzimidazole-based microsomal triglyceride transfer protein inhibitors

A series of benzimidazole-based analogues of the potent MTP inhibitor BMS-201038 were discovered. Incorporation of an unsubstituted benzimidazole moiety in place of a piperidine group afforded potent inhibitors of MTP in vitro which were weakly active in vivo. Appropriate substitution on the benzimidazole ring, especially with small alkyl groups, led to dramatic increases in potency, both in a cellular assay of apoB secretion and especially in animal models of cholesterol lowering. The most potent in this series, 3g (BMS-212122), was significantly more potent than BMS-201038 in reducing plasma lipids (cholesterol, VLDL/LDL, TG) in both hamsters and cynomolgus monkeys.     

Spontaneous cytotoxicity of human intraepithelial lymphocytes against epithelial cell tumors.

Human intraepithelial lymphocytes are T cells primarily of the CD8+ phenotype located between intestinal epithelial cells. The cytotoxic and suppressor activities of these lymphocytes are largely unexplored. The spontaneous cytotoxic activity of these cells is evaluated in this study. Jejunal intraepithelial lymphocytes spontaneously lysed a variety of epithelial cell tumor lines (colonic and pancreatic adenocarcinomas and bladder epidermoid carcinoma) but not the highly natural killer-sensitive K-562 cells. Cold target inhibition studies showed that these lymphocytes preferentially bind the DLD-1 colonic adenocarcinoma cells rather than the K-562 cells. Pretreatment of the effector cells with interferon-gamma did not change their cytotoxic activity. The cytotoxic cells are T lymphocytes (expressing CD2, CD3, and CD8). In contrast, the spontaneous cytotoxic activity of peripheral blood lymphocytes is directed against both epithelial cell targets and K-562 cells, is enhanced by interferon-gamma, and is effected by natural killer cells (expressing CD2, CD16, and NKH1). Thus, the spontaneous cytotoxicity of intraepithelial lymphocytes differs from that of peripheral blood lymphocytes in their target cell restriction, lack of response to interferon gamma, and effector cell phenotype. Lymphocytes in the intestinal epithelium may have a novel and important role in recognizing and destroying transformed epithelial cells and colon cancers.     

Using cryo-EM to measure the dipole potential of a lipid membrane

The dipole potential of a lipid bilayer membrane accounts for its much larger permeability to anions than cations and affects the conformation and function of membrane proteins. The absolute value of the dipole potential has been very difficult to measure, although its value has been estimated to range from 200 to 1,000 mV from ion translocation rates, the surface potential of lipid monolayers, and molecular dynamics calculations. Here, a point charge probe method was used to investigate the dipole potentials of both ester and ether lipid membranes. The interactions between electrons and lipid molecules were recorded by phase-contrast imaging using cryo-EM. The magnitude and the profile of the dipole potential along the bilayer normal were obtained by subtracting the contribution of the atomic potential from the cryo-EM image intensity. The peak dipole potential was estimated to be 510 and 260 mV for diphytanoylphosphatidylcholine and diphytanylphosphatidylcholine, respectively.