Efficacy and outcomes of antiplatelet therapy versus oral anticoagulants in patients undergoing transcatheter aortic valve replacement: a systematic review and meta-analysis.

Background: Recent guidelines suggest that antiplatelet therapy (APT) is the standard of care in the absence of long-term oral anticoagulation (OAC) indications in patients post-transcatheter aortic valve replacement (TAVR). The superiority of one method over the other remains controversial. Materials and methods: Several databases, including MEDLINE, Google Scholar, and EMBASE, were electronically searched. The primary endpoint was the all-cause mortality (ACM) rate. Secondary endpoints included cardiovascular death, myocardial infarction (MI), stroke/TIA, haemorrhagic stroke, bleeding events, systemic embolism, and valve thrombosis in post-TAVR patients receiving APT and oral anticoagulants (OACs). Forest plots were generated using Review Manager version 5.4, with a p value less than 0.05 indicating statistical significance. Subgroup analysis was performed to explore potential sources of heterogeneity. Results: Twelve studies were selected. No significant differences were observed in APT and OAC group for ACM [risk ratio (RR): 0.67; 95% CI:0.45-1.01; P=0.05], cardiovascular death [RR:0.91; 95% CI:0.73-1.14; P=0.42], MI [RR:1.69; 95% CI:0.43-6.72; P=0.46], Stroke/TIA [RR:0.79; 95% CI:0.58-1.06; P=0.12], ischaemic stroke [RR:0.83; 95% CI:0.50-1.37; P=0.47], haemorrhagic stroke [RR:1.08; 95% CI: 0.23-5.15; P=0.92], major bleeding [RR:0.79; 95% CI:0.51-1.21; P=0.28], minor bleeding [RR:1.09; 95% CI: 0.80-1.47; P=0.58], life-threatening bleeding [RR:0.85; 95% CI:0.55-1.30; P=0.45], any bleeding [RR:0.98; 95% CI:0.83-1.15; P=0.78], and systemic embolism [RR:0.87; 95% CI:0.44-1.70; P=0.68]. The risk of valve thrombosis was higher in patients receiving APT than in those receiving OAC [RR:2.61; 95% CI:1.56-4.36; P =0.0002]. Conclusions: Although the risk of valve thrombosis increased in patients receiving APT, the risk of other endpoints was comparable between the two groups.

Epigenetics in Neurological and Psychiatric Disorders: A Comprehensive Review of Current Understanding and Future Perspectives.

The burgeoning field of epigenetics offers transformative insights into the complex landscape of neurological and psychiatric disorders. By unraveling the intricate interplay between genetic, epigenetic, environmental, and lifestyle factors, this comprehensive review highlights the multifaceted nature of mental health. The exploration reveals the potential of epigenetic modifications to revolutionize our understanding, diagnosis, treatment, and prevention of these disorders. Emphasizing the importance of multidisciplinary collaborations, large-scale studies, technological advancements, and ethical considerations, the review asserts the promise of epigenetics as a vital tool for personalized medicine, early intervention, and public health strategies. While acknowledging the challenges in a still-emerging field, the review paints an optimistic picture of epigenetics as a groundbreaking approach that can reshape mental healthcare, offering hope for those affected by neurological and psychiatric conditions. The future trajectory of the field relies on interdisciplinary efforts, ethical diligence, innovative technologies, and translating scientific insights into real-world applications, thereby unlocking the vast potential of epigenetics in mental health.

Comparison of the Efficacy of Cisplatin/Paclitaxel Versus Carboplatin/Paclitaxel in Improving Survival and Quality of Life in the Advanced Ovarian Cancer Patient Population: A Systematic Review and Meta-Analysis of Randomized Control Trials.

Ovarian cancer, being one of the prevalent gynecological cancers, warrants a therapy that's both effective and well tolerated. After extensive drug testing, combination regimens with paclitaxel plus platinum-based agents such as cisplatin/carboplatin and taxanes, have shown promising results for advanced ovarian cancer. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to compare the efficacy of two treatment regimens for advanced ovarian cancer: cisplatin/paclitaxel and carboplatin/paclitaxel.  PubMed (Medline), Science Direct, and Cochrane Library were searched from inception to March 2023. The meta-analysis included patients with histologically verified International Federation of Gynaecology and Obstetrics (FIGO) stages IIB to IV ovarian carcinoma who received either carboplatin/paclitaxel or cisplatin/paclitaxel. The primary outcomes were progression-free survival (PFS), overall survival (OS), quality of life (QOL), complete response rate (CRR), and partial response rate (PRR). The revised Cochrane Risk of Bias Tool 2.0 was used to assess the quality of the RCTs The five RCTs chosen for this statistical analysis consisted of a total of 2239 participants, with 1109 receiving paclitaxel/cisplatin for treatment and the remaining 1130 receiving carboplatin/paclitaxel. Among all included outcomes, these reported significant findings: QoL (p-value=0.0002), thrombocytopenia (p=<0.00001), neurological toxicity (p-value=0.003), nausea/vomiting (p-value=<0.00001), myalgia/arthralgia (p-value=0.02), and febrile neutropenia (p-value=0.01). We concluded that the carboplatin/paclitaxel doublet endows a better quality of life (QOL) to patients along with significantly fewer gastrointestinal and neurological toxicities when compared with the cisplatin/paclitaxel combination. However, the myelosuppressive effects of carboplatin/paclitaxel remain a point of concern and may require clinical management.

Growth arrest of PPP2R5C and PPP2R5D double knockout mice indicates a genetic interaction and conserved function for these PP2A B subunits.

Protein phosphatase 2A (PP2A) is a heterotrimeric phosphatase that controls a wide range of cellular functions. The catalytic activity and intracellular location of PP2A are modulated by its association with regulatory B subunits, including B56 proteins, which are encoded by five separate genes in humans and mice. The specific effects of each B56 protein on PP2A activity and function are largely unknown. As part of an effort to identify specific PP2A-B56 functions, we created knockout strains of B56ß, B56δ, and B56ε using CRISPR/Cas9n. We found that none of the individual B56 genes are essential for mouse survival. However, mice that have both B56δ and B56γ inactivated (B56δγ-), arrest fetal development around Day E12. The hearts of B56δγ- mice have a single outflow vessel rather than having both an aorta and a pulmonary artery. Thus, there appears to be strong genetic interaction between B56δ and B56γ, and together they are necessary for heart development. Of note, both these proteins have been shown to localize to the nucleus and have the most related peptide sequences of the B56 family members. Our results suggest there are B56 subfamilies, which work in conjunction to regulate specific PP2A functions.

Natural history of monoclonal B-cell lymphocytosis among relatives in CLL families.

Chronic lymphocytic lymphoma (CLL) has one of the highest familial risks among cancers. Monoclonal B-cell lymphocytosis (MBL), the precursor to CLL, has a higher prevalence (13%-18%) in families with 2 or more members with CLL compared with the general population (5%-12%). Although, the rate of progression to CLL for high-count MBLs (clonal B-cell count ≥500/µL) is ∼1% to 5%/y, no low-count MBLs have been reported to progress to date. We report the incidence and natural history of MBL in relatives from CLL families. In 310 CLL families, we screened 1045 relatives for MBL using highly sensitive flow cytometry and prospectively followed 449 of them. MBL incidence was directly age- and sex-adjusted to the 2010 US population. CLL cumulative incidence was estimated using Kaplan-Meier survival curves. At baseline, the prevalence of MBL was 22% (235/1045 relatives). After a median follow-up of 8.1 years among 449 relatives, 12 individuals progressed to CLL with a 5-year cumulative incidence of 1.8%. When considering just the 139 relatives with low-count MBL, the 5-year cumulative incidence increased to 5.7%. Finally, 264 had no MBL at baseline, of whom 60 individuals subsequently developed MBL (2 high-count and 58 low-count MBLs) with an age- and sex-adjusted incidence of 3.5% after a median of 6 years of follow-up. In a screening cohort of relatives from CLL families, we reported progression from normal-count to low-count MBL to high-count MBL to CLL, demonstrating that low-count MBL precedes progression to CLL. We estimated a 1.1% annual rate of progression from low-count MBL, which is in excess of that in the general population.

Evaluation of the differentiation status of neural stem cells based on cell morphology and the expression of Notch and Sox2.

Neural stem cells (NSCs) isolated from a variety of sources are being developed as cellular therapies aimed at treating neurodegenerative diseases. During NSC culture and expansion it is important the cells do not differentiate prematurely because this may have an unfavorable effect on product quality and yield. In our study, we evaluated the use of Notch and Sox2 as markers for undifferentiated human and mouse NSCs. The expression of Notch2 and Sox2 during extensive-passage, low-oxygen culture and differentiation conditions were analyzed to confirm that the presence of these signature proteins directly correlates with the ability of NSCs to form new neurospheres and differentiate into multiple cell types. Using expression of Notch1, Notch2 and Sox2 as a reference, we then used flow cytometry to identify a specific morphological profile for undifferentiated murine and human NSCs. Our studies show that Notch and Sox2 expression, along with flow cytometry analysis, can be used to monitor the differentiation status of NSCs grown in culture for use in cellular therapies.

PP2A-B56γ is required for an efficient spindle assembly checkpoint.

The Spindle Assembly Checkpoint (SAC) is part of a complex feedback system designed to ensure that cells do not proceed through mitosis unless all chromosomal kinetochores have attached to spindle microtubules. The formation of the kinetochore complex and the implementation of the SAC are regulated by multiple kinases and phosphatases. BubR1 is a phosphoprotein that is part of the Cdc20 containing mitotic checkpoint complex that inhibits the APC/C so that Cyclin B1 and Securin are not degraded, thus preventing cells going into anaphase. In this study, we found that PP2A in association with its B56γ regulatory subunit, are needed for the stability of BubR1 during nocodazole induced cell cycle arrest. In primary cells that lack B56γ, BubR1 is prematurely degraded and the cells proceed through mitosis. The reduced SAC efficiency results in cells with abnormal chromosomal segregation, a hallmark of transformed cells. Previous studies on PP2A's role in the SAC and kinetochore formation were done using siRNAs to all 5 of the B56 family members. In our study we show that inactivation of only the PP2A-B56γ subunit can affect the efficiency of the SAC. We also provide data that show the intracellular locations of the B56 subunits varies between family members, which is consistent with the hypothesis that they are not completely functionally redundant.

Quantitative Flow Cytometry Measurements in Antibodies Bound per Cell Based on a CD4 Reference.

Multicolor flow cytometer assays with fluorescently labeled antibodies are routinely used in clinical laboratories to measure the cell number of specific immunophenotypes and to estimate expression levels of specific receptors/antigens either on the cell surface or intracellularly. The cell number and specific receptors/antigens serve as biomarkers for pathological conditions at various stages of a disease. Existing methods and cell reference materials for quantitative expression measurements have not yet produced results that are of wide clinical interest or are instrument-independent across all fluorescence channels. This unit details a procedure for quantifying surface and intracellular biomarkers by calibrating the output of a multicolor flow cytometer in units of antibody bound per cell (ABC). The procedure includes (1) quality control of the flow cytometer, (2) fluorescence intensity calibration using hard dyed microspheres assigned with fluorescence intensity values, (3) compensation for fluorescence spillover between adjacent fluorescence channels, and (4) application of a biological reference calibrator to establish an ABC scale. The unit also points out current efforts for quantifying biomarkers in a manner that is independent of instrument platforms and reagent differences.

Consistent, multi-instrument single tube quantification of CD20 in antibody bound per cell based on CD4 reference.

Detecting changes in the expression levels of cell antigens could provide critical information for the diagnosis of many diseases, for example, leukemia, lymphoma, and immunodeficiency diseases, detecting minimal residual disease, monitoring immunotherapies and discovery of meaningful clinical disease markers. One of the most significant challenges in flow cytometry is how to best ensure measurement quality and generate consistent and reproducible inter-laboratory and intra-laboratory results across multiple cytometer platforms and locations longitudinally over time. In a previous study, we developed a procedure for instrument standardization across four different flow cytometer platforms from the same manufacturer. CD19 quantification was performed on three of the standardized instruments relative to CD4 expression on T lymphocytes with a known amount of antibody bound per cell (ABC) as a quantification standard. Consistent and reliable measures of CD19 expression were obtained independent of fluorochrome used demonstrating the utility of this approach. In the present investigation, quantification of CD20 relative to CD4 reference marker was implemented within a single tube containing both antibodies. Relative quantification of CD20 was performed using anti-CD20 antibody (clone L27) in three different fluorochromes relative to anti-CD4 antibody (clone SK3). Our results demonstrated that cell surface marker quantification can be performed robustly using the single tube assay format with novel gating strategies. The ABC values obtained for CD20 expression levels using PE, APC, or PerCP Cy5.5 are consistent over the five different instrument platforms for any given apparently healthy donor independent of the fluorochrome used.

Quantification of cells with specific phenotypes I: determination of CD4+ cell count per microliter in reconstituted lyophilized human PBMC prelabeled with anti-CD4 FITC antibody.

A surface-labeled lyophilized lymphocyte (sLL) preparation has been developed using human peripheral blood mononuclear cells prelabeled with a fluorescein isothiocyanate conjugated anti-CD4 monoclonal antibody. The sLL preparation is intended to be used as a reference material for CD4+ cell counting including the development of higher order reference measurement procedures and has been evaluated in the pilot study CCQM-P102. This study was conducted across 16 laboratories from eight countries to assess the ability of participants to quantify the CD4+ cell count of this reference material and to document cross-laboratory variability plus associated measurement uncertainties. Twelve different flow cytometer platforms were evaluated using a standard protocol that included calibration beads used to obtain quantitative measurements of CD4+ T cell counts. There was good overall cross-platform and counting method agreement with a grand mean of the laboratory calculated means of (301.7 ± 4.9) µL(-1) CD4+ cells. Excluding outliers, greater than 90% of participant data agreed within ±15%. A major contribution to variation of sLL CD4+ cell counts was tube to tube variation of the calibration beads, amounting to an uncertainty of 3.6%. Variation due to preparative steps equated to an uncertainty of 2.6%. There was no reduction in variability when data files were centrally reanalyzed. Remaining variation was attributed to instrument specific differences. CD4+ cell counts obtained in CCQM-P102 are in excellent agreement and show the robustness of both the measurements and the data analysis and hence the suitability of sLL as a reference material for interlaboratory comparisons and external quality assessment.

Quantifying CD4 receptor protein in two human CD4+ lymphocyte preparations for quantitative flow cytometry.

BACKGROUND: In our previous study that characterized different human CD4+ lymphocyte preparations, it was found that both commercially available cryopreserved peripheral blood mononuclear cells (PBMC) and a commercially available lyophilized PBMC (Cyto-Trol™) preparation fulfilled a set of criteria for serving as biological calibrators for quantitative flow cytometry. However, the biomarker CD4 protein expression level measured for T helper cells from Cyto-Trol was about 16% lower than those for cryopreserved PBMC and fresh whole blood using flow cytometry and mass cytometry. A primary reason was hypothesized to be due to steric interference in anti- CD4 antibody binding to the smaller sized lyophilized control cells. METHOD: Targeted multiple reaction monitoring (MRM) mass spectrometry (MS) is used to quantify the copy number of CD4 receptor protein per CD4+ lymphocyte. Scanning electron microscopy (SEM) is utilized to assist searching the underlying reasons for the observed difference in CD4 receptor copy number per cell determined by MRM MS and CD4 expression measured previously by flow cytometry. RESULTS: The copy number of CD4 receptor proteins on the surface of the CD4+ lymphocyte in cryopreserved PBMCs and in lyophilized control cells is determined to be (1.45 ± 0.09) × 10(5) and (0.85 ± 0.11) × 10(5), respectively, averaged over four signature peptides using MRM MS. In comparison with cryopreserved PBMCs, there are more variations in the CD4 copy number in lyophilized control cells determined based on each signature peptide. SEM images of CD4+ lymphocytes from lyophilized control cells are very different when compared to the CD4+ T cells from whole blood and cryopreserved PBMC. CONCLUSION: Because of the lyophilization process applied to Cyto-Trol control cells, a lower CD4 density value, defined as the copy number of CD4 receptors per CD4+ lymphocyte, averaged over three different production lots is most likely explained by the loss of the CD4 receptors on damaged and/or broken microvilli where CD4 receptors reside. Steric hindrance of antibody binding and the association of CD4 receptors with other biomolecules likely contribute significantly to the nearly 50% lower CD4 receptor density value for cryopreserved PBMC determined from flow cytometry compared to the value obtained from MRM MS.

Monoclonal B-cell lymphocytosis in healthy blood donors: an unexpectedly common finding.

Circulating monoclonal B cells may be detected in healthy adults, a condition called monoclonal B-cell lymphocytosis (MBL). MBL has also been identified in donated blood, but no systematic study of blood donors has been reported. Using sensitive and specific laboratory methods, we detected MBL in 149 (7.1%; 95% confidence interval, 6.0% to 8.3%) of 2098 unique donors ages 45 years or older in a Midwestern US regional blood center between 2010 and 2011. Most of the 149 donors had low-count MBL, including 99 chronic lymphocytic leukemia-like (66.4%), 22 atypical (14.8%), and 19 CD5(-) (12.8%) immunophenotypes. However, 5 donors (3.4%) had B-cell clonal counts above 500 cells per µL, including 3 with 1693 to 2887 cells per µL; the clone accounted for nearly all their circulating B cells. Four donors (2.7%) had 2 distinct MBL clones. Of 51 MBL samples in which immunoglobulin heavy chain (IGH)V-D-J genotypes could be determined, 71% and 29% used IGHV3- and IGHV4-family genes, respectively. Sequencing revealed 82% with somatic hypermutation, whereas 18% had >98% germ-line identity, including 5 with entirely germ-line sequences. In conclusion, MBL prevalence is much higher in blood donors than previously reported, and although uncommon, the presence of high-count MBL warrants further investigations to define the biological fate of the transfused cells in recipients.

Bcl-2 level as a biomarker for 13q14 deletion in CLL.

BACKGROUND: Deletion 13q14.3 is the most common cytogenetic abnormality in chronic lymphocytic leukemia (CLL). Previously it was reported that miR-15/16 is the target of 13q14 deletions and plays a tumor suppressor role by suppressing Bcl-2. Therefore, Bcl-2 expression was examined more closely to determine whether it would predict 13q14 deletion status. METHODS: A multi-color flow panel consisting of anti-Bcl-2/anti-lambda/anti-kappa/CD19/CD5/CD3/CD20 was performed. The ability of Bcl-2 to predict 13q14 deletion was tested using the conventional Bcl-2 index (c-index): mean fluorescence intensity (MFI) of CLL clone/MFI of residual T cells. Fifty-four untreated CLL/MBL patients were studied. Bimodal Bcl-2 expression was evaluated to test the ability of Bcl-2 to detect intraclonal heterogeneity. Other CLL prognostic markers including CD38, CD49d, CD26, and CD69 were evaluated. FISH was performed on selected sorted populations. RESULTS: The Bcl-2 c-index strongly predicts del13q14 P < 0.0001. A statistically significant association was observed between the percentage of cells carrying the deletion and the level of Bcl-2 expression P < 0.05. Cells sorted based on Bcl-2 expression showed enrichment of both hemizygous and homozygous del 13q14 cells. Also, we observed that an alteration in Bcl-2 level over time predicts changes in 13q14 deletion status. And a statistically significant correlation between the bimodal pattern of CD69 expression and the presence of 13q14 deletion was found P < 0.0001. CONCLUSION: Bcl-2 expression using the c-index strongly predicts 13q14 deletion and can be used to distinguish homozygous, heterozygous, and diploid CLL clonal cells. Further systematic studies of this biomarker are needed for confirmation and expansion of these findings.

Quantitative detection of zeta-chain-associated protein 70 expression in chronic lymphocytic leukemia.

Overexpression of zeta-chain-associated protein 70 (ZAP-70) was recently recognized as an independent prognostic marker for the aggressive form of chronic lymphocytic leukemia (CLL). The objective of this study was to demonstrate the feasibility and implementation of quantitative detection of ZAP-70 protein in B cells to clearly distinguish patients with CLL with the aggressive form of the disease. B cells were isolated from patient blood and lysed. Released ZAP-70 protein was detected using an immunomagnetic fluorescence assay. The assay protocol was developed using Jurkat cells and recombinant ZAP-70 (rZAP-70). The limit of detection was determined to be lower than 125 Jurkat cells and 39 pg of rZAP-70 protein. The signal response was linear over a wide dynamic range, from 125 to 40 000 Jurkat cells per test (R(2) = 0.9987) and from 0 to 40 000 pg rZAP-70 protein per test (R(2) = 0.9928). The results from 20 patients with CLL correlated strongly with flow cytometry analysis. Concordance between the two methods for positive and negative results was 100% (7/7) and 92% (12/13), respectively, while the overall concordance between the two methods was 95%. The assay reported here is a simple, reliable and reproducible method for quantitative detection of ZAP-70 in patient leukemic cells, without the need for cell fixation or permeabilization. The ZAP-70 signal was linear over a wide dynamic range, which we believe enables quantitative assessment of small changes in ZAP-70 expression over the course of the disease and in response to therapeutic intervention.

Human CD4+ lymphocytes for antigen quantification: characterization using conventional flow cytometry and mass cytometry.

To transform the linear fluorescence intensity scale obtained with fluorescent microspheres to an antibody bound per cell (ABC) scale, a biological cell reference material is needed. Optimally, this material should have a reproducible and tight ABC value for the expression of a known clinical reference biomarker. In this study, we characterized commercially available cryopreserved peripheral blood mononuclear cells (PBMCs) and two lyophilized PBMC preparations, Cyto-Trol and PBMC-National Institute for Biological Standard and Control (NIBSC) relative to freshly prepared PBMC and whole blood samples. It was found that the ABC values for CD4 expression on cryopreserved PBMC were consistent with those of freshly obtained PBMC and whole blood samples. By comparison, the ABC value for CD4 expression on Cyto-Trol is lower and the value on PBMC-NIBSC is much lower than those of freshly prepared cell samples using both conventional flow cytometry and CyTOF™ mass cytometry. By performing simultaneous surface and intracellular staining measurements on these two cell samples, we found that both cell membranes are mostly intact. Moreover, CD4(+) cell diameters from both lyophilized cell preparations are smaller than those of PBMC and whole blood. This could result in steric interference in antibody binding to the lyophilized cells. Further investigation of the fixation effect on the detected CD4 expression suggests that the very low ABC value obtained for CD4(+) cells from lyophilized PBMC-NIBSC is largely due to paraformaldehyde fixation; this significantly decreases available antibody binding sites. This study provides confirmation that the results obtained from the newly developed mass cytometry are directly comparable to the results from conventional flow cytometry when both methods are standardized using the same ABC approach.

Combined normal donor and CLL: Single tube ZAP-70 analysis.

INTRODUCTION: Zeta-chain-associated protein kinase 70 (ZAP-70) has been identified as an independent prognostic marker in chronic lymphocytic leukemia (CLL). Based on our previous studies, we have developed a combined one-tube technology with multiple internal controls to optimize ZAP-70 assessment. METHODS: Forty-eight untreated CLL cases were examined for ZAP-70 expression using a modified 7-color one-tube assay. Normal donor (ND) whole blood is stained with CD3 APC-Cy7 and CD19 APC. In a second tube, patient whole blood is stained with CD5 PE-Cy7, CD19 PerCP-Cy5.5, and CD20 eFluor450. After surface staining and fixation, these two tubes are combined. After saponin permeabilization, the cells were stained with two anti-ZAP-70 clones (1E7.2/AF488 and SBZAP/PE). The results obtained from this modified tube were compared with those obtained concurrently using the non-mixed single sample tubes. Five different methods of ZAP-70 expression analysis were evaluated: percentage positive cells using ND T-cells as a reference; the internal patient T-cell/clone ratio; ND T-cell/clone ratio; clone/ND B-cell ratio; and modified Z-index. RESULT: Overall, the combined patient and ND mix tube performed better than the non-mixed single sample tube. The strongest correlations between ZAP-70 expression and immunoglobulin heavy chain variable (IGHV) mutational status were seen with percentage positive ND T-cell, ND T-cell/clone ratio, and clone/ND B-cell ratio for both 1E7.2 and SBZAP clone (P < 0.0001). CONCLUSION: The modified one tube method combining the ND and patient sample provides highly reliable results that correlate with the IGHV mutational status. This method should be considered as part of the next step in standardization of the ZAP-70 assay in CLL.

Methodological comparison of two anti-ZAP-70 antibodies.

BACKGROUND: ZAP-70 expression is a stage independent prognostic marker in CLL. However, interlaboratory variation is large, and there is neither a consensus nor a regulatory approved methodology. METHODS: Two anti-ZAP70 clones (1E7.2 and SBZAP) were compared in 45 untreated CLL patients. Nine different methods for ZAP-70 expression analysis were evaluated: M1, isotype control to determine negative; M2, internal residual T-cell to determine positive; M3, normal donor (ND) T-cell to determine positive; M4, internal T-cell/clone ratio; M5, ND residual T-cell/clone ratio; M6, clone/normal remaining B-cell ratio; M7, clone/ND B- cell ratio; M8, CLL-Z score; M9, modified CLL-Z score. A scoring system was designed integrating both 1E7.2 and SBZAP clones to assign ZAP-70 expression. RESULTS: The correlation coefficients for the four selected highest statistically significant methods were as follows (M1 = 0.71, M3 = 0.72, M7 = 0.67, and M9 = 0.64). These four methods were used to generate a combined score. The two reagents showed agreement using the designed scoring system for 37/45 samples (82%), and 8/45 (18%) showed equivocal result with one of the two clones. Seven of the eight equivocal samples were resolved using the scoring system. CONCLUSIONS: Four of the nine methods of analysis were compared for each reagent. The use of two independent ZAP-70 reagents increases analytical certitude and the scoring method aids in the resolution of equivocal results. The combined use of two reagents, four methods of analysis, and a scoring method allowed for assignment of ZAP-70 expression in 44/45 samples (98%) tested and improved performance of this important prognostic assay.

Improved ZAP-70 assay using two clones, multiple methods of analysis and clinical correlation.

INTRODUCTION: In a companion methodological study, we compared two anti-ZAP-70 clones (1E7.2 AF 488 and SBZAP PE) and four selected methods of analysis. Clinical correlations are required for validation. METHODS: Multicolor flow-cytometric evaluation of ZAP-70, CD38, CD69, CD26, CD49d, and CD27 was tested in 45 untreated-CLL patients. Four methods of ZAP-70 expression analysis and a scoring system were designed. A correlation analysis between ZAP-70 score, immunoglobulin heavy chain variable (IGHV) mutational status, fluorescence in situ hybridization, and these biomarkers was undertaken. RESULTS: There is a strong correlation between ZAP-70 expression and IGHV mutational status. The scoring system for a single reagent (P = 0.0006 or 0.0002) favors the use of multiple methods of analysis. The combined score was substantially equivalent (P = 0.0003). There was also a correlation with del 13q14 (P = 0.017) and trisomy12 (P = 0.011). A correlation for CD38 and ZAP-70 score was seen using both 1E7.2 AF488 and SBZAP PE when ≥20% or ≥7% cutoff was used. A positive correlation was seen for CD49d expression using both reagents. CD26 showed a correlation with ZAP-70 expression, but it was dependent upon the method of analysis. CD69 and CD27 showed no statistically significant correlation. CONCLUSION: In our study population, ZAP-70 expression is the better predictor of the IGHV mutational status. The correlation analysis confirms that the use of four methods of analysis with a single reagent or both reagents is superior to the use of a single method of analysis. The routine use of CD38, CD49d, and CD26 will require standardization.

Variables in the quantification of CD4 in normals and hairy cell leukemia patients.

BACKGROUND: Quantitative flow cytometry (QFCM) is being applied in the clinical flow cytometry laboratory. Quantitative normal T-cell CD4 expression represents a biologic standard and quality control agent. However, low levels of CD4 expression were detected in normal T-cells in Hairy Cell Leukemia (HCL) samples. METHODS: The QuantiBrite System® was used to determine the level of CD4 expression (mean antibody bound per cell, ABC) in fresh and shipped HCL blood and fresh normal donor blood (NDB). The effects of shipping, lysing reagent, cell preparation method, and antibody lot were evaluated. RESULTS: Shipped HCL specimens (n = 69) had a significantly lower mean CD4 ABC of 38,788 (CV = 9.1%) compared to fresh specimens (n = 105) CD4 value of 40,330 (CV = 8.4%) (P < 0.05). In NDB, significant differences were seen for fresh versus shipped specimens using the stain/lyse method but not for lyse/stain method. Consistent differences in CD4 ABC based upon antibody lot were observed in fresh HCL and NDB samples. Stain/lyse and lyse/stain methods using NH(4) Cl lyse were compared in NDB using identical samples and antibodies. The NDB CD4 ABC values obtained with the lyse (NH(4) Cl)/stain method (45,562, 3.7% CV) were lower than those obtained with the stain/lyse (NH(4) Cl) method (49,955, 3.3% CV) with P < 0.001. CONCLUSIONS: CD4 expression in HCL patient samples is not inherently different from that observed in NDB and therefore may serve as a biological control in clinical QFCM. Technical variables impact significantly on QFCM of CD4.

Prevalence of monoclonal B-cell lymphocytosis: a systematic review.

BACKGROUND: Individuals with monoclonal B-cell lymphocytosis (MBL) have been identified in clinic outpatients, in unaffected relatives of patients with chronic lymphocytic leukemia (CLL), and in general populations. MBL and its relationship with CLL have been actively investigated over the last decade. This report systematically reviews the prevalence of MBL in the context of the populations studied and the evolution of laboratory methods used to define MBL. METHODS: To identify published studies that have assessed the prevalence of MBL, we systematically searched the MEDLINE databases and consulted with members of the International MBL Study Group. We reviewed the 10 articles that were identified by this process. We abstracted information on study populations, laboratory tests, criteria for designating MBL, and the reported frequencies. RESULTS: Three of the ten studies were published in 2009, three between 2007 and 2008, and four between 2002 and 2004. Reported prevalences varied widely, ranging from 0.12 to 18.2%. This variability was clearly associated with both the laboratory methods and the populations studied. MBL was more common among older individuals and kindred of persons with CLL. The most common MBL subtype was CLL-like MBL. CONCLUSIONS: Large population-based studies of MBL that employ standardized laboratory methods with a consensus case definition are needed to assess prevalence and establish risk factors. These studies should include prospective follow-up of MBL cases to determine the relationship between MBL and CLL. Data from original studies should be reported in sufficient detail to allow future synthesis of information from multiple studies, such as meta-analysis.