CD38 Expression and Variation as a Prognostic Factor Chronic Lymphocytic Leukemia

BACKGROUND

In this study, we aimed to determine a cutoff level for CD38 that would aid us in identifying chronic lymphocytic leukemia patients in need of early therapy and predicting patients at sufficiently low risk who would likely exhibit a rapid improvement; we also aimed to find out if CD38 expression would show variability during disease course and determine the extent of CD38 expression.

METHODS

124 patients were diagnosed with CLL. CD38 and ZAP-70 expression levels were measured with four color flowcytometry. Time from diagnosis to initial therapy was calculated for all patients. CD38 expression was studied for a second time during follow-up in 50 patients.

RESULTS

For cutoff levels of 7%, 20%, and 30%, CD38 expressions were 61.3%, 25%, and 24.2%, respectively. At all three cutoff levels there were significant correlations with all parameters except age between CD38+ vs. CD38- groups (p < 0.001). The comparative rates of starting therapy for cutoff levels of 7%, 20%, and 30% in CD38+ and CD38- groups were 77.5% vs. 6.25%; 100% vs. 30.7%, and 100% vs. 31.5%, respectively (p < 0.001). Multiple Cox Proportional Hazards Regression analysis: for a cutoff level of 7%, survival was affected by STAGE, ZAP70, and CD38.

CONCLUSIONS

A CD38 cutoff level of 7% determined by standardized laboratory techniques is an important prognostic marker. However, the number and frequency of repeat measurements of CD38 expression, and cutoff level of CD38 expression that significantly predict disease prognosis should be further determined by future cohort studies.

Gene expression profiling of peripheral blood cells: new insights into Ewing sarcoma biology and clinical applications

Ewing sarcoma (ES) is a group of highly aggressive small round cell tumors of bone or soft tissue with high metastatic potential and low cure rate. ES tumors are associated with a rapid osteolysis and necrosis. The currently accepted clinical prognostic parameters do not accurately predict survival of high-risk patients. Moreover, neither the subtype of EWS-FLI1/ERG in the tumor, nor the detection of fusion transcripts in the peripheral blood (PB) samples, has prognostic value in ES patients. We evaluated the prevalence of circulating tumor cells (CTCs) in 34 adult ES patients. Since CTCs were confirmed in only small subset of patients, we further explored the expression profiles of PB leukocytes using a panel of genes associated with immune system status and increased tumor invasiveness. Moreover, we analyzed the alterations of the routine blood tests in the examined cohort of patients and correlated our findings with the clinical outcome. A uniform decrease in ZAP70 expression in PB cells among all ES patients, as compared to healthy individuals, was observed. Monocytosis and the abnormal expression of CDH2 and CDT2 genes in the PB cells significantly correlated with poor prognosis in ES patients. Our study supports the previously proposed hypothesis of systemic nature of ES. Based on the PB cell expression profiles, we propose a mechanism by which immune system may be involved in intensification of osteoclastogenesis and disease progression in ES patients. Moreover, we demonstrate the prognostic value of molecular PB testing at the time of routine histopathological diagnosis.

Role of high expression of IL-9 in prognosis of CLL

Chronic lymphocytic leukemia (CLL) is a common leukemia in adults, but its pathogenesis is still poorly understood. Interleukin-9 (IL-9) is initially described as a growth factor secreted by helper T cells. Recently, the oncogenic activities of IL-9 were reported in some leukemia but not chronic lymphocytic leukemia (CLL). The purpose of the present study is to investigate the expression of IL-9 from patients with CLL and to evaluate its correlation with clinical characteristics. Serum and peripheral blood mononuclear cells (PBMCs) from patients with CLL were analyzed using ELISA, RT-PCR, and western blot. ELISA analysis indicated IL-9 could be detected in 20 of 47 sera from CLL patients while none serum sample from healthy volunteers contained detectable levels of IL-9. There was a higher expression of IL-9 within PBMCs from patients with CLL compared with B cells of healthy blood donors using RT-PCR and western blot. The upregulated IL-9 was correlated to the clinical staging, ZAP-70 expression, β2 microglobulin expression and IgVH status of CLL patients (P<0.05). Our findings suggest that overexpression of IL-9 may contribute to the pathogenesis of CLL and is associated with some adverse prognostic parameters.

Copper levels in patients with hematological malignancies

BACKGROUND

Copper levels are elevated in cancer patients compared to normal subjects. However, few studies have investigated the relationship between copper and hematological malignancies.

METHODS

84 patients with hematological diseases were studied, along with 50 healthy individuals. Copper was measured by flame atomic absorption spectrometry. The patients were classified to 2 homogeneous groups, acute and chronic hematological neoplasms, respectively. For the patients with acute hematological malignancies, relapse and remission were investigated in relation to serum copper levels. For chronic hematological neoplasms, serum copper was connected either with stable or progressive disease. Zeta-chain-associated protein kinase 70 (ZAP70) and CD38 expression, along with the unmutated VH immunoglobulin genes (IgVH) status were also determined for the 22 chronic lymphocytic leukemia (CLL) patients.

RESULTS

54 patients with relapse or progressive disease had elevated copper levels (mean value 1.8 mg/l), whereas 30 patients either in remission or in stable disease had normal copper levels (mean value 1.01 mg/l) (normal range 0.8-1.3mg/l).

CONCLUSION

Hence, our study indicates that serum elevated copper levels are associated with hematological malignancies either in relapse or in disease progression, whereas normal copper levels are linked with hematological neoplasms in remission or in stable disease. Furthermore, we report for the first time an association between high serum copper levels and several adverse prognostic markers in CLL, such as increased expression of ZAP70 and CD38, along with elevated percentage of unmutated IgVH.

Survival trends among 1,325 patients with chronic lymphocytic leukemia seen over the past 40 years in Israel

In the light of recent data showing survival improvement of patients with chronic lymphocytic leukemia (CLL), we investigated clinical characteristics and survival patterns of patients with CLL over the last 40 years in Israel. Demographic and clinical data collected in the database of the Israeli CLL Study Group were analyzed. Of the 1,325 patients, 221 were diagnosed during the time period 1968-1989, 456 during 1990-1999, and 639 during 2000-2010. There was shift toward older age (median, 71 vs. 68 vs. 66 years) and a higher proportion of patients at Binet stage A at diagnosis (77.6% vs. 66.7% vs. 60.3%) in the more recent time periods. Median survival for the entire cohort was 10.9 years; 12.2 years for patients diagnosed at Binet stage A, 8.5 years for stage B, and 6.4 years for stage C patients. Older age, high-beta 2-microglobulin level, and expression of ZAP-70 predicted shorter survival. There were no apparent changes over time regarding gender, age or different clinical stages. Young patients with Binet stage A had lower life expectancy than the general population; but, in older ages, the survival rates were comparable. There were increased proportions of CLL patients diagnosed in early stages, and, at older age, during the last decades, however, survival rates according to sex, age, or stage remained stable. CLL continues to be an incurable disease affecting survival even in patients diagnosed at early stages. Survival benefit shown in recent trials using chemoimmunotherapy has still to be proven in wider general practice.

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.

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.

Identifying the stage of new CLL patients using TK, ZAP-70, CD38 levels

Serum thymidine kinase (TK), zeta-associated protein of 70 kDa (ZAP-70) and CD38 levels have been shown to be correlated with survival in chronic lymphocytic leukaemia (CLL).

AIM

To investigate the possible correlations between TK, ZAP-70 and CD38 levels as prognostic markers in new diagnosed Rai stages of CLL patients.

METHODS

120 CLL patients were enrolled. ELISA was used to measure serum TK level, flow cytomerty - to determine ZAP-70 and CD38 expression applying ZAP-70 Kit and monoclonal antibody to CD38, respectively.

RESULTS

Significantly higher levels of TK were found in the high progression group of CLL patients that corresponded to stage II (Rai classification). An elevated level of TK, CD38 and ZAP-70 together was also found in the II stage. The coefficient of correlation between CD38 and ZAP-70 is reliable (p < 0.001). There is also a correlation between the level of TK and the disease stage (p < 0.05). Other parameters do not show this correlation.

CONCLUSION

The determination of TK, ZAP-70 and CD38 together allows patients susceptible to a possible stage of the disease, to be identified. Estimation of the factors at an early stage of the disease may allow an earlier commencement of treatment.

CCL3 (MIP-1α) plasma levels and the risk for disease progression in chronic lymphocytic leukemia

B-cell receptor (BCR) signaling has been inferred as an important mechanism for disease progression in chronic lymphocytic leukemia (CLL) and other B-cell malignancies. In response to BCR activation, CLL cells secrete the chemokine CCL3, which fosters interactions between CLL cells and the leukemia microenvironment. CCL3 secretion correlates with expression of the 70-kDa ζ-associated protein (ZAP-70) and responsiveness of the CLL clone to BCR stimulation. Here, we measured CCL3 plasma levels by enzyme-linked immunosorbent assay (ELISA) in 351 CLL patients and examined CCL3 levels for associations with established prognostic markers and time from diagnosis to initial therapy. We found that CCL3 plasma concentrations were strongly associated with established prognostic markers. In a Cox proportional hazards regression model, CCL3 as well as established prognostic markers (immunoglobulin heavy chain variable-region mutation status, CD38 or ZAP-70 cytogenetics, clinical stage) were significantly associated with time to treatment. Multivariable analysis revealed that CCL3 (hazard ratio [HR] = 2.33, P < .0001), advanced clinical stage (HR = 2.75, P = .0025), poor risk cytogenetics (del 17p, HR = 2.38; del11q, HR = 2.36, P = .001), and CD38 expression (HR = 1.43, P = .023) were independent prognostic markers. Collectively, CCL3 is a novel, robust, and independent prognostic marker in CLL that can easily and reliably be measured by ELISA. CCL3 therefore should become useful for risk assessment in patients with CLL.

Prognostic significance of serum immunoglobulin paraprotein in patients with chronic lymphocytic leukemia

The aim of this study was to explore the clinical and other associated laboratory features of chronic lymphocytic leukemia (CLL) patients with immunoglobulin (Ig) paraproteinemia. Serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE) were performed to measure serum Ig paraprotein. The correlations between serum Ig paraprotein and other prognostic factors were analyzed. Univariate and multivariate Cox regression analyses were used to assess associations between survival time and potential risk factors. In 133 Chinese CLL patients, 27 (20.3%) patients occurred Ig paraproteinemia at diagnosis. According to the correlation analysis, advanced Binet stage (r=0.314, P<0.001), direct antiglobulin test (DAT)-positive (r=0.366, P<0.001), high level of serum β2-microglobulin (β2-MG) (r=0.296, P=0.001) and thymidine kinase (TK) 1 (r=0.227, P=0.037), unmutated immunoglobulin heavy chain variable gene (IGHV) status (r=0.284, P=0.002), ZAP-70-positive (r=0.305, P=0.001), CD38-positive (r=0.284, P=0.002), and cytogenetic abnormalities of del(17p13) or del(11q22.3) (r=0.208, P=0.032) emerged as factors significantly related to the occurrence of Ig paraproteinemia. Survival analysis showed that the patients with Ig paraproteinemia had significantly shorter survival times than the patients without serum Ig paraprotein (P=0.013). Binet stage (P=0.028), high levels of lactate dehydrogenase (LDH) (P=0.004), IgG paraproteinemia (P=0.048), IgM paraproteinemia (P=0.001), ZAP-70-positive (P=0.003), DAT-positive (P=0.013), unmutated IGHV status (P=0.009), and del(17p13) (P=0.001) were the adverse factors in determining overall survival (OS). Del(17p13) (P=0.006), ZAP-70 (P=0.030), and IgM paraproteinemia (P=0.040) were the variables strongly associated with OS by multivariate Cox regression analysis. It was showed that serum Ig paraprotein might be applied for the assessment of prognosis in patients with CLL.

The study of different chromosomal aberrations, CD38 and ZAP-70 in chronic lymphocytic leukemia patients

Chronic lymphocytic leukemia (CLL) follows an extremely variable clinical course with overall survival times ranging from months to decades. The clinical staging systems do not allow one to predict if and at what rate there will be disease progression in an individual patient diagnosed with early stage disease. There has been intensive work on clinical and biological factors of potential prognostic relevance that may add to the classic assessment provided by the staging systems. Among these are: Laboratory parameters reflecting the tumor burden or disease activity such as lymphocyte count, lactate dehydrogenase (LDH) elevation, bone marrow infiltration pattern or lymphocyte doubling time (LDT), serum markers such as soluble CD23, beta2-microglobulin (beta2-MG) or thymidine kinase (TK), and genetic markers of tumor cells such as genomic aberrations, the mutation status of the variable segments of immunoglobulin heavy chain genes (VH), or surrogate markers for these factors (CD38, ZAP-70, LPL). Thirty patients were included in our study, the investigation included CD38 expression, ZAP-70 expression, and interphase Fluorescence In Situ Hybridization (FISH) for the detection of trisomy 12, del 13q14.3, del 17p13, and del 11q22.3. Our results showed positive statistical significant correlation between ZAP-70 expression and CD38 expression with some of the chromosomal aberrations encompassing bad prognosis as ATM and p53. Also CD38 expression was positively correlated with trisomy 12 and p53 deletions. Chromosomal aberrations were found to be present in 76.6% of our patients with 13q deletion as the most frequent abnormality in our patients (46.7%), followed by trisomy 12 (36.7%), then ATM and p53 deletion (26.7%) each. Another interesting finding in our study is the fact that 100% of the ZAP-70 positive patients were of bad prognosis, 58.3% of the CD38 positive cases, 81.8% of the positive trisomy 12 cases, 100% of the ATM deletion, 62.5% of the p53 deletion, and 64.3% of the 13q- cases were also of bad prognosis, which indicates that ZAP-70, trisomy 12, and ATM deletion are powerful indicators of prognosis. We conclude that FISH for the detection of the most important chromosomal aberrations in CLL is an important laboratory parameter that is recommended for assessment and correlation with simultaneous evaluation of ZAP-70 and CD38 expression which could help in the prediction of outcome of CLL patients.

Prognostic impact of ZAP-70 expression in chronic lymphocytic leukemia: mean fluorescence intensity T/B ratio versus percentage of positive cells

BACKGROUND

ZAP-70 is an independent negative prognostic marker in chronic lymphocytic leukemia (CLL). Usually, its expression is investigated by flow cytometric protocols in which the percentage of ZAP-70 positive CLL cells is determined in respect to isotypic control (ISO-method) or residual ZAP-70 positive T cells (T-method). These methods, however, beside suffering of an inherent subjectivity in their application, may give discordant results in some cases. The aim of this study was to assess the prognostic significance of these methods in comparison with another in which ZAP-70 expression was evaluated as a Mean-Fluorescence-Intensity Ratio between gated T and CLL cells (T/B Ratio-method).

METHODS

Cytometric files relative to ZAP-70 determination according to the three readouts were retrospectively reviewed on a cohort of 173 patients (test set), all with complete clinical and biological prognostic assessment and time-to-treatment (TTT) available. Findings were then validated in an independent cohort of 341 cases from a different institution (validation set).

RESULTS

The optimal prognostic cut-offs for ZAP-70 expression were selected at 11% (ISO-method) or 20% of positive cells (T-method), as well as at 3.0 (T/B Ratio-method) in the test set; these cut-offs yielded 66, 60 and 73 ZAP-70+ cases, respectively. Univariate analyses resulted in a better separation of ZAP-70+ vs. ZAP-70- CLL patients utilizing the T/B Ratio, compared to T- or ISO-methods. In multivariate analyses which included the major clinical and biological prognostic markers for CLL, the prognostic impact of ZAP-70 appeared stronger when the T/B-Ratio method was applied. These findings were confirmed in the validation set, in which ZAP-70 expression, evaluated by the T- (cut-off = 20%) or T/B Ratio- (cut-off = 3.0) methods, yielded 180 or 127 ZAP-70+ cases, respectively. ZAP-70+ patients according to the T/B Ratio-method had shorter TTT, both if compared to ZAP-70- CLL, and to cases classified ZAP-70+ by the T-method only.

CONCLUSIONS

We suggest to evaluate ZAP-70 expression in routine settings using the T/B Ratio-method, given the operator and laboratory independent feature of this approach. We propose the 3.0 T/B Ratio value as optimal cut-off to discriminate ZAP-70+ (T/B Ratio less than 3.0) from ZAP-70- (T/B Ratio more/equal than 3.0) cases.

ZAP-70 positive cells in treated and untreated HIV-1 infected patients

ZAP-70 is a critical protein tyrosine kinase in T-cell activation and proliferation processes. Defective recruitment of ZAP-70 molecules results in termination of the T-cell receptor (TCR) signal transduction pathway. Impairment of this pathway is one of the early markers of disease progression in HIV-1 infected individuals. T-cell dysfunction in HIV infected patients may be connected to a defect in the proximal TCR signaling cascade. To evaluate this presumption, the numbers and mean fluorescence intensity (MFI) of ZAP-70 positive cells in patients with treated and untreated HIV-1 infection and healthy controls were analyzed by flow cytometry. A correlation between the MFI in ZAP 70 molecules and the viral load was evaluated. A total of 41 HIV-1 infected patients, 30 patients on HAART and 11 untreated patients, and 11 healthy controls were enrolled. The data show ZAP-70+/CD4+ cells in treated and untreated HIV-1 infected individuals had a greater MFI of ZAP-70 molecules than those from healthy controls (p < 0.001). The inverse correlation between the percentage of CD4+cells and the MFI of ZAP-70+/CD4+ T-cells was significant (r = -0.5; p < 0.01). A stronger correlation between the percentage of CD4+/CD25+ cells and the MFI of ZAP-70+/CD4+ cells was observed (r =-0.6; p < 0.01). However, no significant correlation was seen between the MFI of the ZAP-70+/CD4+cells and the viral load in patients with untreated HIV-1 infection (r = -0.4, p = 0.16). For HIV-1 treated patients, the viral loads were too low to detect so it was not possible to calculate the correlation. Elevated MFI levels of ZAP-70 molecules in CD4+ cells in HIV infected patients may be associated with an inability to further activate T-cells.

Detection of ZAP-70 in patients with chronic lymphocytic leukemia

PURPOSE

To determine the presence and prognostic significance of ZAP-70 in patients with B chronic lymphocytic leukemia (B-CLL). Expression of ZAP-70 in B-CLL is a continuum ranging from absent to high, affecting the prognostic reliability of this marker.

PATIENTS AND METHODS

32 patients with B-CLL treated from March 2006 to February 2007 were prospectively studied. Patients were stratified in two groups: those diagnosed with B-CLL within 18 months and a retrospective group diagnosed before 18 months since the beginning of this study. Patients were predominantly males (78.1%), over 60 years old (81.25%). ZAP-70 was detected on EPICX-XL flow cytometer with System II software. Directly conjugated antibodies CD19 PE, ZAP-70 FITC (clone 1E7.2) and CD2 APC were used. Leuoperm was used for permeabilization. All samples with over 20% ZAP-70/CD19 double positive B lymphocytes were considered positive.

RESULTS

ZAP-70 was absent in a group of 22 patients with B-CLL diagnosed over 18 months from the beginning of this study, while 2 out of 10 (20%) patients from the group of newly diagnosed patients were ZAP-70(+). During follow up both ZAP-70(+) cases showed worsening of their clinical status resulting to death in one patient. In borderline cases with ZAP-70(+) ranging from 10.9-19.9% there was no correlation of the level of ZAP-70 expression with disease activity or clinical scoring systems.

CONCLUSION

Very high percentage of ZAP-70(+) cells is a sign of poor prognosis in B-CLL. Borderline expression of ZAP-70, although more frequent, could not be successfully assigned into a risk group.

Prognostic relevance of serum levels and cellular expression of adiponectin in B-cell chronic lymphocytic leukemia

The correlation between well-established biological parameters of prognostic relevance in B-cell chronic lymphocytic leukaemia (CLL) [i.e., mutational status of the immunoglobulin heavy chain variable region (IgV(H)), ZAP-70- and CD38-expression] and adiponectin serum concentration was evaluated in a cohort of 69 previously untreated Binet stage A CLL patients. Adiponectin levels inversely correlated with absolute peripheral blood lymphocyte count (r = -0.254; P = 0.03), CD38-positive CLL cells (r = -0.294; P = 0.04) and ZAP-70 (r = -0.285; P = 0.03). The univariate Cox proportional hazard model demonstrated that, in addition with lower serum levels of adiponectin (P = 0.01), the unmutated IgV(H) condition (P = 0.002) and ZAP-70-positivity (P = 0.02) were associated with a shorter time to first treatment (TFT). However, in multivariate analysis only ZAP-70 positivity emerged as predictor of the TFT (P = 0.008). The levels of adiponectin in CLL were evaluated in 60 patients from an independent cohort investigated by gene expression profiling. Adiponectin gene expression was invariably low suggesting a limited (if any) role of leukemic cells in the production of circulating adiponectin levels. In contrast, both adiponectin receptor 1 (AdipoR1) and AdipoR2 mRNA were highly expressed by CLL cells with a degree of inter-patient variability. Our results, although preliminary, lend support to the idea that adiponectin secretion by bone marrow adipocytes might represent a possible promising drug target in the field of hematology.

Quantification of ZAP70 mRNA in B Cells by Real-Time PCR Is a Powerful Prognostic Factor in Chronic Lymphocytic Leukemia

Background: Chronic lymphocytic leukemia (CLL) is heterogeneous with respect to prognosis and clinical outcome. The mutational status of the immunoglobulin variable heavy chain region (IGHV) has been used to classify patients into 2 groups in terms of overall survival (OS) and clinical characteristics, but the labor-intensive nature and the cost of this time-consuming analysis has prompted investigations of surrogate markers.

Methods: We developed a standardized quantitative real-time reverse transcription-PCR (qPCR) method to measure zeta-chain (TCR)-associated protein kinase (ZAP70) mRNA in purified CD19+ cells. We evaluated this and other methods (flow cytometry analyses of ZAP70 and CD38 proteins and qPCR analysis of lipoprotein lipase mRNA) in a cohort of 108 patients (median follow-up, 82 months) to evaluate any associations with IGHV mutational status, OS, and treatment-free survival (TFS).

Results: The association between qPCR-measured ZAP70 and IGHV mutational status was statistically significant [χ2 (1) = 50.95; P &lt;0.0001], and the value of Cramer’s V statistic (0.72) indicated a very strong relation. This method also demonstrated sensitivity, specificity, and positive and negative predictive values of 87.8%, 85.7%, 87.5%, and 86%, respectively. ZAP70 expression was significantly associated with OS (P = 0.0021) and TFS (P &lt;0.0001). ZAP70+ patients had significantly shorter median TFS (24 months) than ZAP70− patients (157 months) (P &lt;0.0001). Moreover, qPCR-measured ZAP70 expression has greater prognostic power than IGHV mutational status and the other prognostic markers tested.

Conclusions: ZAP70 mRNA quantification via qPCR is a strong surrogate marker of IGHV mutational status and a powerful prognostic factor.

National standardization of ZAP-70 determination by flow cytometry: the French experience

BACKGROUND

ZAP-70, after being considered as a potential surrogate for VH mutational status, has seen its own prognostic value emerge. We aimed at standardizing a simple, fast, and reproducible flow cytometry method.

METHODS

AntiZAP-70 antibody 2F3.2 was used with indirect labeling and secondary anti-IgG2a antibody. The reference values for the expression of the results were determined on 45 normal blood samples. ZAP-70 protein expression was investigated in 192 CLL samples. The indirect technique was compared with FITC-conjugated 2F3.2 clone, and with clone 1E7.2-FITC, -PE or -AlexaFluor 488.

RESULTS

Using FITC or PE-conjugated antibodies, 2F3.2 and 1E7.2 clones allowed a much less adequate discrimination between positive and negative cells and discordant cases were most likely true negative cases. Using the AlexaFluor 488 conjugated 1E7.2 clone, the discordant cases were mostly negative with the conjugated antibody and positive with the 2F3.2 clone but Western blotting or RNA microarray confirmed discordant cases were false negative with the conjugated antibody. Subsequently, recommendations were used by 13 centers participating in an interlaboratory quality control protocol. The use of MFI ratio appeared to be more reliable.

CONCLUSIONS

Results suggested that slight differences in the procedure had little impact on the interpretation in characteristic cases; however, careful interpretation was required for values close to threshold.

Negative signaling contributes to T-cell anergy in trauma patients

OBJECTIVE

Maintenance of postinjury T-lymphocyte immune paralysis or anergy could result from failure to activate costimulatory receptors during T-cell receptor activation and/or from chronic stimulation of a competing set of elevated corepressor receptors. Our objective was to assess whether elevated posttrauma T-lymphocyte surface expression of corepressor receptors was associated with immunodepressed lymphocyte responses and corresponded to increased inhibitory and decreased activating signal transduction molecules.

DESIGN

Prospective observational study.

SETTING

University trauma intensive care unit and research laboratory.

PATIENTS

Sixty-one severe thermal and mechanical trauma patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Isolated trauma patients' and controls' peripheral blood T cells were assayed for negative and positive costimulation receptor expression. These receptor expression levels were compared (flow cytometry) between the two groups and correlated to T-cell levels of inhibitory and activating signal transduction molecules and proliferation capacity. Patients' proliferation hyporesponsive (anergic) T cells had increased expression of novel inhibitory receptors (corepressors) PD-1 (p < .05) and CD47 (p < .05) vs. patients' T-cell proliferation competent or controls' T cells. Patients' T-cell CD152 (CTLA-4) expression was also elevated vs. controls. Only patients' anergic T cells had simultaneously increased levels of the inhibitory signal transduction proteins, c-Cbl, a ubiquitin-ligase (p < .01) and SHP-1, a phosphatase (p < .01), concomitant to depressed phosphorylation of the activating signal kinases Erk, Zap70, and CD3Euro. T-cell receptor complex phosphorylation and activation of the interleukin-2 pivotal transcriptional complex protein CREB were also simultaneously depressed as c-Cbl and SHP-1 were elevated.

CONCLUSIONS

Up-regulated corepressor receptor expression is novelly shown to characterize trauma patients' anergic T cells and correlate with predominance of inhibitory overactivating signal transduction molecules during T-cell stimulation. This could contribute to postinjury immunosuppression.

Lipoprotein Lipase mRNA Expression in Whole Blood Is a Prognostic Marker in B Cell Chronic Lymphocytic Leukemia

Background: Chronic lymphocytic leukemia (CLL) is characterized by high individual variability in clinical course and the need for therapy. Differentiation of prognostic subgroups is based primarily on the mutation status of the genes for the variable region of the immunoglobulin heavy chain (IGHV). The time- and labor-intensive nature of this analysis necessitates the use of easily applicable surrogate markers.

Methods: We developed a quantitative PCR (qPCR) method for determining lipoprotein lipase (LPL) mRNA expression and analyzed samples of lysed whole blood and CD19-selected cells from 50 CLL patients. Associations of LPL and ZAP70 [ζ-chain (TCR) associated protein kinase 70 kDa] expression with IGHV mutation status, overall survival (OS), and treatment-free survival (TFS) were investigated.

Results: Lysed samples of whole blood and CD19-selected cells were similar with respect to LPL expression (R = 0.88; P &lt;0.0001). LPL expression was significantly associated with IGHV mutation status [χ2(1) = 15.3; P &lt;0.0001] and showed an 89.3% specificity, a 68.2% sensitivity, an 83.3% positive predictive value, and a 78.1% negative predictive value for IGHV mutation status. LPL expression was significantly associated with both OS and TFS in log-rank tests (both P values = 0.002). LPL-positive patients had a significantly shorter median TFS time (23 months) than LPL-negative patients (88 months) (P = 0.002).

Conclusions: LPL mRNA expression is a valuable prognostic marker in CLL. The method does not require cell purification, and its applicability with archived samples facilitates its use in the clinical routine and other studies.

Comparative analysis of ZAP-70 expression and Ig VH mutational status in B-cell chronic lymphocytic leukemia

BACKGROUND

B-cell chronic lymphocytic leukemia (CLL) is a heterogeneous disorder with respect to its clinical course. Accurate identification of prognostic factors is becoming increasingly important in order to determine those patients requiring aggressive treatments. Two of the most predictive outcome markers are the Ig VH mutational gene status and ZAP-70 expression. In earlier reports, both parameters have shown a high degree of concordance. To assess the value of these determinations in clinical practice, we simultaneously analyzed Ig VH mutations and ZAP-70 expression in a consecutive series of B-CLL.

METHODS

Fifty-three consecutive B-CLL cases were included in the study. ZAP-70 expression was investigated by flow cytometry. Positivity was established using two methods: comparing ZAP70 expression in B-cells with T-cells using cytoplasmic CD3 (ZAP-70/T) and with NK-cell reactivity (ZAP-70/NK). The complete immunophenotype was recorded in each case. Ig VH mutational gene status was determined employing purified RNA from peripheral blood samples. Retrotranscribed DNA was PCR-amplified, direct-sequenced, and compared with available public databases. VH3.21 family use was also recorded.

RESULTS

Using a T-cell marker, 58% of patients were ZAP-70+ and 42% were ZAP-70-. NK-cell comparisons gave only 6% of ZAP-70 positivity in B-CLL, and in six cases the absence of a clearly defined NK-cell population precluded the ZAP70 analysis. Twenty-four (45%) patients had mutated Ig VH genes and 29 (55%) had unmutated Ig VH genes. The results showed a statistical association between ZAP-70/T expression and VH mutational status. Despite this, in 30% of cases there was a discordant result. Immunophenotypic analysis showed no major differences in Matutes'score between mutated and nonmutated cases. Only FMC7 was more commonly expressed in the unmutated B-CLL cases. VH3.21 was present in 7.5% of cases, mostly having an unmutated pattern.

CONCLUSIONS

ZAP-70 reactivity using a T-cell marker as a control allows to identify the majority of patients with an unmutated Ig VH genotype. Parallel analysis revealed that discordances with Ig VH analysis are quite common with currently employed flow cytometry reagents and techniques.

Prognostic importance of soluble CD23 in B-cell chronic lymphocytic leukemia

Soluble CD23 (sCD23) was proposed as a marker of disease activity and as an important prognostic parameter in B-cell chronic lymphocytic leukemia (B-CLL). In this study, prognostic significance of sCD23 in B-CLL was examined according to its temporal relationship with the known clinical parameters of the disease, CD38 and ZAP-70. Serum sCD23 levels of 36 B-CLL patients, followed up in our clinic between 1999 and 2005, and 15 healthy subjects were measured with enzyme-linked immunosorbent assay. The mean serum sCD23 level of the B-CLL patients (210.72 +/- 193.67 and 6-600 U/ml) was significantly higher than the control group (18.20 +/- 14.30 and 6-50 U/ml). Seventy-eight percent of the B-CLL patients with lymphocyte doubling time (LDT) <12 months and 24% of patients with LDT >12 months had high sCD23 levels (P = 0.008). Meanwhile, 81% of the patients with diffuse bone marrow infiltration and 33% of patients with nondiffuse infiltration had high levels of serum sCD23 (P = 0.029). A significant difference was found between B-CLL patients with Binet stages A and C (P = 0.009). Peripheral blood flow cytometry of the patients revealed a significant CD38 expression in patients with high serum sCD23 levels (P = 0.002). Similarly, an increased bone marrow zeta-chain associated protein kinase-70 (ZAP-70) expression was seen in patients with high serum sCD23 levels (P = 0.009, correlation co-efficient was 0.714). Cumulative and the progression free survivals of the patients with low serum sCD23 levels were 60.1 +/- 5.7 months [95% confidence interval (CI); 49.0-71.2] and 51.1 +/- 6.6 months (95% CI; 38.0-64.1), respectively. However, they were 43.8 +/- 6.5 months (95% CI; 31.0-56.6) and 26.5 +/- 6.4 months (95% CI; 14.0-39.1) in patients with high levels. Serum sCD23 is increased in B-CLL patients and can be used in the clinical follow-up of the disease in prediction of the tumor mass and prognosis.

B cell chronic lymphocytic leukaemia/small lymphocytic lymphoma: role of ZAP70 determination on bone marrow biopsy specimens

BACKGROUND

The course of chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL) partly depends on the mutational status of the variable region of immunoglobulin heavy chain genes (IgV(H)), which defines two subgroups of tumours: mutated and unmutated. The expression of zeta-associated protein 70 (ZAP70) is significantly associated with the more aggressive unmutated forms.

AIMS

To assess the feasibility of the ZAP70 immunohistochemical test on bone-marrow biopsy (BMB) specimens and to compare the results with those of western blotting (WB) and IgV(H) mutational status assessed on neoplastic cells from peripheral blood.

METHODS

26 patients with CLL/SLL detected on BMB and with known IgV(H) mutational status were selected. ZAP70 was determined by immunohistochemistry (IHC) comparing three antibodies from different sources (Upstate, Cell Signaling, Santa Cruz, California, USA) and two different methods (APAAP and EnVision(+)). In 23 cases, ZAP70 WB results were also available.

RESULTS

ZAP70 determination on BMB specimens turned out to be easily feasible with routine procedures with reagents from Upstate and Cell Signaling. The results were concordant with those obtained with WB and mutational status analysis in >80% of the cases with both reagents. Three of four discordant cases were mutated/ZAP70 positive, with two staining weakly for ZAP70 on both WB and IHC.

CONCLUSIONS

The study confirms the role of ZAP70 as a possible surrogate of mutational status and emphasises its application in routine diagnostics; it discloses a small subset of discordant cases (mutated/ZAP70 weakly positive) that clinically cluster with the more favourable forms.

Clinical significance of soluble p53 protein in B-cell chronic lymphocytic leukemia

BACKGROUND AND OBJECTIVES

p53 status and CD38 antigen are biological factors influencing response to therapy and clinical course in B-cell chronic lymphocytic leukemia (B-CLL). This study tests the hypothesis that soluble p53 alone and in association with CD38 can enucleate B-CLL subsets at worse prognosis.

DESIGN AND METHODS

Wild and mutant forms of p53 protein were evaluated in 197 B-CLL patients at diagnosis or before progression by an immunoenzymatic method in plasma using an anti-p53 monoclonal antibody. CD38 expression was analyzed by a multicolor flow cytometric assay.

RESULTS

Higher levels of both soluble p53 (sp53) and CD38 were significantly correlated with intermediate and high Rai stages, with higher beta2-microglobulin and soluble CD23 values, determined at diagnosis. Shorter overall survival (OS) and progression-free survival (PFS) were both observed in sp53+ and CD38+ patients (p<0.0001). Simultaneous positivity or negativity for sp53 and CD38 identified two subsets of patients, the former with a worse prognosis and the latter with a better prognosis with regard to PFS (p<0.0001) and OS (p<0.0001). The predictive value of sp53 and CD38 was retained among the patients within the intermediate Rai risk group.

INTERPRETATION AND CONCLUSIONS

sp53 and CD38 together with ZAP-70 were confirmed to be independent prognostic factors in multivariate analysis. With regard to PFS, ZAP-70, sp53 and CD38 were confirmed to be independent prognostic factors. Concerning OS, ZAP-70, CD38 and age (< or > 60 years) were independent prognostic factors whereas sp53 showed only a tendency towards statistical significance.