Lactate dehydrogenase (LDH) isoenzymes and proliferative activity of lymphoid cells--an immunocytochemical study

Vagal Nerve Activity Predicts Prognosis in Diffused Large B-Cell Lymphoma and Multiple Myeloma

This study examined the prognostic role of vagal nerve activity in patients with relapsed/refractory diffused large B-cell lymphoma (R/R-DLBCL) treated with chimeric antigen receptor cell therapy (CAR-T) and in patients with multiple myeloma (MM) undergoing an autologous hematopoietic cell transplantation (AutoHCT). Participants included 29 patients with R/R-DLBCL and 37 patients with MM. Inclusion criteria were: (1) age over 18; (2) diagnosed with DLBCL or MM; (3) being treated with CAR-T or AutoHCT; and (4) having an ECG prior to cell transfusion. The predictor was vagal nerve activity indexed by heart rate variability (HRV) and obtained retroactively from 10 s ECGs. The main endpoint for R/R-DLBCL was overall survival (OS), and for MM the endpoint was progression-free survival (PFS). Data of 122 patients were obtained, 66 of whom were included in the study. In DLBCL, HRV significantly predicted OS independently of confounders (e.g., performance status, disease status at cell therapy), hazard ratio (HR), and 95% confidence interval (HR = 0.20; 95%CI: 0.06-0.69). The prognostic role of disease severity was moderated by HRV: among severely disease patients, 100% died with low HRV, while only 37.5% died with high HRV. In MM, HRV significantly predicted PFS (HR = 0.19; 95%CI: 0.04-0.90) independently of confounders. Vagal nerve activity independently predicts prognosis in patients with R/R-DLBCL and with MM undergoing cell therapy. High vagal activity overrides the prognostic role of disease severity. Testing the effects of vagal nerve activation on prognosis in blood cancers is recommended.

Lactate dehydrogenase/albumin ratio as a prognostic factor in severe acute respiratory distress syndrome cases associated with COVID-19

BACKGROUND

Patients with severe acute respiratory distress syndrome (ARDS) have high mortality rates; therefore, new biomarkers are necessary to predict the prognosis in the early stages. Serum lactate dehydrogenase (LDH) level is a specific marker of lung damage, but it is not sensitive because it is affected by several factors. This study aimed to determine whether the LDH/albumin ratio could be used as a prognostic biomarker in patients with severe ARDS due to COVID 19.

METHODS

Tertiary intensive care unit (ICU) patients with severe ARDS and confirmed COVID-19 diagnosis between August 1, 2020, and October 31, 2021, were included. The demographic and clinical characteristics of the patients were recorded from the hospital databases, together with laboratory results on the day of admission to the ICU and the length of stay in the ICU and hospital. LDH/albumin, lactate/albumin, C-reactive protein (CRP)/albumin, and BUN/albumin ratios were calculated. Logistic regression analysis was performed to determine independent risk factors affecting mortality.

RESULTS

Nine hundred and five patients hospitalized in a tertiary ICU were evaluated. Three hundred fifty-one patients with severe ARDS were included in this study. The mortality rate of the included patients was 61.8% (of 217/351). LDH/albumin, lactate/albumin, and BUN/albumin ratios were higher in the nonsurvivor group (P < .001). The area under the curve (AUC) from the receiver operating characteristic analysis that predicted in-hospital mortality was 0.627 (95% confidence intervals (CI): 0.574-0.678, P < .001) for the LDH/albumin ratio, 0.605 (95% CI: 0.551-0.656, P < .001) for lactate/albumin, and 0.638 (95% CI: 0.585-0.688, P < .001) for BUN/albumin. However, LDH/albumin ratio was independently associated with mortality in multivariate logistic regression analysis.

CONCLUSION

LDH/albumin ratio can be used as an independent prognostic factor for mortality in patients with severe ARDS caused by COVID-19.

The many lives of Myc in the pancreatic β-cell

Diabetes results from insufficient numbers of functional pancreatic β-cells. Thus, increasing the number of available functional β-cells ex vivo for transplantation, or regenerating them in situ in diabetic patients, is a major focus of diabetes research. The transcription factor, Myc, discovered decades ago lies at the nexus of most, if not all, known proliferative pathways. Based on this, many studies in the 1990s and early 2000s explored the potential of harnessing Myc expression to expand β-cells for diabetes treatment. Nearly all these studies in β-cells used pathophysiological or supraphysiological levels of Myc and reported enhanced β-cell death, dedifferentiation, or the formation of insulinomas if cooverexpressed with Bcl-xL, an inhibitor of apoptosis. This obviously reduced the enthusiasm for Myc as a therapeutic target for β-cell regeneration. However, recent studies indicate that "gentle" induction of Myc expression enhances β-cell replication without induction of cell death or loss of insulin secretion, suggesting that appropriate levels of Myc could have therapeutic potential for β-cell regeneration. Furthermore, although it has been known for decades that Myc is induced by glucose in β-cells, very little is known about how this essential anabolic transcription factor perceives and responds to nutrients and increased insulin demand in vivo. Here we summarize the previous and recent knowledge of Myc in the β-cell, its potential for β-cell regeneration, and its physiological importance for neonatal and adaptive β-cell expansion.

Consolidative allogeneic hematopoietic stem cell transplantation after chimeric antigen receptor T-cell therapy for relapsed/refractory B-cell acute lymphoblastic leukemia: who? When? Why?

Although anti-CD19 chimeric antigen receptor (CAR) T-cell therapy shows good efficacy in patients with relapsed/refractory B-cell acute lymphoblastic leukemia (r/r B-ALL), it fails to improve long-term leukemia-free survival (LFS). Allogeneic hematopoietic stem cell transplantation (allo-HSCT) after CAR T-cell therapy has emerged as a promising strategy to prolong LFS. Nevertheless, which patients are likely to benefit from consolidative allo-HSCT, as well as the optimal therapeutic window, remain to be explored. Recent clinical data indicate that patients with complex karyotypes, adverse genes, and high pre-infusion minimal residual disease (MRD) by flow cytometry in the bone marrow, were at high risk of relapse after CAR T-cell therapy. High pre-lymphodepletion lactate dehydrogenase, low pre-lymphodepletion platelet count, absence of fludarabine in lymphodepletion, persistent leukemic sequence by high throughput sequencing in bone marrow after CAR T-cell infusion, and early loss of CAR T cells have also been linked to relapse after CAR T-cell therapy. In patients having these risk factors, consolidative allo-HSCT after CAR T-cell therapy may prolong LFS. Allo-HSCT provides optimal clinical benefit in patients with MRD-negative complete remission, typically within three months after CAR T-cell therapy. Herein, we summarize the clinical data on consolidative allo-HSCT after anti-CD19 CAR T-cell therapy, as well as the potential factors associated with allo-HSCT benefit. We also discuss the optimal therapeutic window and regimen of consolidative allo-HSCT. Finally, and most importantly, we provide recommendations for the assessment and management of r/r B-ALL patients undergoing anti-CD19 CAR T-cell therapy.

Influence of patient characteristics on chimeric antigen receptor T cell therapy in B-cell acute lymphoblastic leukemia

CD19-specific chimeric antigen receptor T cell (CD19 CAR T) therapy has shown high remission rates in patients with refractory/relapsed B-cell acute lymphoblastic leukemia (r/r B-ALL). However, the long-term outcome and the factors that influence the efficacy need further exploration. Here we report the outcome of 51 r/r B-ALL patients from a non-randomized, Phase II clinical trial (ClinicalTrials.gov number: NCT02735291). The primary outcome shows that the overall remission rate (complete remission with or without incomplete hematologic recovery) is 80.9%. The secondary outcome reveals that the overall survival (OS) and relapse-free survival (RFS) rates at 1 year are 53.0 and 45.0%, respectively. The incidence of grade 4 adverse reactions is 6.4%. The trial meets pre-specified endpoints. Further analysis shows that patients with extramedullary diseases (EMDs) other than central nervous system (CNS) involvement have the lowest remission rate (28.6%). The OS and RFS in patients with any subtype of EMDs, higher Tregs, or high-risk genetic factors are all significantly lower than that in their corresponding control cohorts. EMDs and higher Tregs are independent high-risk factors respectively for poor OS and RFS. Thus, these patient characteristics may hinder the efficacy of CAR T therapy.

CAR T therapy has some efficacy in the treatment of patients with refractory/relapsed B-cell acute lymphoblastic leukemia; however in some patients further relapse is encountered. Here, the authors conduct a Phase II clinical trial of a CD19 CAR T and demonstrate that patients with extramedullary disease are more likely to relapse than those without.

Clinical significance of tryptophan catabolism in follicular lymphoma

The enzyme, indoleamine 2,3-dioxygenase 1 (IDO), catabolizes tryptophan (Trp) in the kynurenine (Kyn) pathway, and is important in suppressing antitumor immune responses in the tumor microenvironment. With regard to previously untreated patients with follicular lymphoma (FL), we sought to establish the prognostic significance of Trp catabolism in this disease. Serum Trp and Kyn levels in 110 patients with FL were quantified, and their relationship to different clinical parameters studied. IDO expression in the lymph nodes of affected patients was studied. Study participants included 54 males and 56 females (age range 39-86, median 62 years), showing a 5-year overall survival (OS) rate of 78.5%. Patients with a high Kyn level (5-year OS, 65.0% vs. 81.7%; p = 0.026), high Kyn/Trp ratio (71.1% vs. 81.7%; p = 0.002), and low hemoglobin (Hb) level (<12.0 g/dL; p = 0.001; a component of FL international prognostic indexes) demonstrated a significantly shorter OS. Multivariate analysis included the following 10 variables: age, sex, serum β2-microglobulin, Hb, longest diameter of the largest involved node, Ann Arbor stage, serum lactate dehydrogenase, histologic grading, B symptoms, and serum Kyn/Trp ratio; a lower Hb level and a high Kyn/Trp ratio (HR, 3.239; 95% CI, 1.296-8.096) led to a significantly inferior OS. In the microenvironment, some CD11c-positive myeloid dendritic cells but not FL tumor cells were found to produce IDO. Overall, measuring levels of serum Kyn and Trp in individual patients with FL contributed to predicting their prognosis.

Lactate dehydrogenase, an independent risk factor of severe COVID-19 patients: a retrospective and observational study

BACKGROUND

The World Health Organization has declared coronavirus disease 2019 (COVID-19) a public health emergency of global concern. Updated analysis of cases might help identify the risk factors of illness severity.

RESULTS

The median age was 63 years, and 44.9% were severe cases. Severe patients had higher APACHE II (8.5 vs. 4.0) and SOFA (2 vs. 1) scores on admission. Among all univariable parameters, lymphocytes, CRP, and LDH were significantly independent risk factors of COVID-19 severity. LDH was positively related both with APACHE II and SOFA scores, as well as P/F ratio and CT scores. LDH (AUC = 0.878) also had a maximum specificity (96.9%), with the cutoff value of 344.5. In addition, LDH was positively correlated with CRP, AST, BNP and cTnI, while negatively correlated with lymphocytes and its subsets.

CONCLUSIONS

This study showed that LDH could be identified as a powerful predictive factor for early recognition of lung injury and severe COVID-19 cases.

METHODS

We extracted data regarding 107 patients with confirmed COVID-19 from Renmin Hospital of Wuhan University. The degree of severity of COVID-19 patients (severe vs. non-severe) was defined at the time of admission according to American Thoracic Society guidelines for community acquired pneumonia.

The response to lymphodepletion impacts PFS in patients with aggressive non-Hodgkin lymphoma treated with CD19 CAR T cells

Factors associated with durable remission after CD19 chimeric antigen receptor (CAR)-modified T-cell immunotherapy for aggressive B-cell non-Hodgkin lymphoma (NHL) have not been identified. We report multivariable analyses of factors affecting response and progression-free survival (PFS) in patients with aggressive NHL treated with cyclophosphamide and fludarabine lymphodepletion followed by 2 × 10⁶ CD19-directed CAR T cells/kg. The best overall response rate was 51%, with 40% of patients achieving complete remission. The median PFS of patients with aggressive NHL who achieved complete remission was 20.0 months (median follow-up, 26.9 months). Multivariable analysis of clinical and treatment characteristics, serum biomarkers, and CAR T-cell manufacturing and pharmacokinetic data showed that a lower pre-lymphodepletion serum lactate dehydrogenase (LDH) level and a favorable cytokine profile, defined as serum day 0 monocyte chemoattractant protein-1 (MCP-1) and peak interleukin-7 (IL-7) concentrations above the median, were associated with better PFS. MCP-1 and IL-7 concentrations increased after lymphodepletion, and higher intensity of cyclophosphamide and fludarabine lymphodepletion was associated with higher probability of a favorable cytokine profile. PFS was superior in patients who received high-intensity lymphodepletion and achieved a favorable cytokine profile compared with those who received the same intensity of lymphodepletion without achieving a favorable cytokine profile. Even in high-risk patients with pre-lymphodepletion serum LDH levels above normal, a favorable cytokine profile after lymphodepletion was associated with a low risk of a PFS event. Strategies to augment the cytokine response to lymphodepletion could be tested in future studies of CD19 CAR T-cell immunotherapy for aggressive B-cell NHL. This trial was registered at www.clinicaltrials.gov as #NCT01865617.

Factors associated with durable EFS in adult B-cell ALL patients achieving MRD-negative CR after CD19 CAR T-cell therapy

Autologous T cells engineered to express a CD19-specific chimeric antigen receptor (CAR) have produced impressive minimal residual disease-negative (MRD-negative) complete remission (CR) rates in patients with relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL). However, the factors associated with durable remissions after CAR T-cell therapy have not been fully elucidated. We studied patients with relapsed/refractory B-ALL enrolled in a phase 1/2 clinical trial evaluating lymphodepletion chemotherapy followed by CD19 CAR T-cell therapy at our institution. Forty-five (85%) of 53 patients who received CD19 CAR T-cell therapy and were evaluable for response achieved MRD-negative CR by high-resolution flow cytometry. With a median follow-up of 30.9 months, event-free survival (EFS) and overall survival (OS) were significantly better in the patients who achieved MRD-negative CR compared with those who did not (median EFS, 7.6 vs 0.8 months; P < .0001; median OS, 20.0 vs 5.0 months; P = .014). In patients who achieved MRD-negative CR by flow cytometry, absence of the index malignant clone by IGH deep sequencing was associated with better EFS (P = .034). Stepwise multivariable modeling in patients achieving MRD-negative CR showed that lower prelymphodepletion lactate dehydrogenase concentration (hazard ratio [HR], 1.38 per 100 U/L increment increase), higher prelymphodepletion platelet count (HR, 0.74 per 50 000/μL increment increase), incorporation of fludarabine into the lymphodepletion regimen (HR, 0.25), and allogeneic hematopoietic cell transplantation (HCT) after CAR T-cell therapy (HR, 0.39) were associated with better EFS. These data allow identification of patients at higher risk of relapse after CAR T-cell immunotherapy who might benefit from consolidation strategies such as allogeneic HCT. This trial was registered at www.clinicaltrials.gov as #NCT01865617.

Transient alleviation of tumor hypoxia during first days of antiangiogenic therapy as a result of therapy-induced alterations in nutrient supply and tumor metabolism - Analysis by mathematical modeling

A number of experiments on mouse tumor models, as well as certain clinical data, have demonstrated, that antiangiogenic therapy can lead to transient improvement in tumor oxygenation, that allows to increase efficiency of following radiotherapy. In the majority of works, this phenomenon has been explained by enhanced tumor perfusion due to normalization of capillaries' structure, that results in elevated oxygen inflow in tumor. However, changes in tumor perfusion often haven't been directly measured in relevant works, moreover, antiangiogenic therapy has been proven to have ambiguous effect on tumor perfusion both in mouse tumor models and in clinics. Herein, we suggest that elevation of blood perfusion may be not the only reason for transient alleviation of tumor hypoxia, and that it may manifest itself even under unchanged tumor blood flow. We propose that it may be as well caused by the decrease in tumor oxygen consumption rate (OCR) due to the reduction of tumor proliferation level, caused by nutrient shortage in result of antiangiogenic treatment. We provide detailed explanation of this hypothesis and visualize it using a specially developed mathematical model, which takes into account basic features of tumor growth and antiangiogenic therapy. We investigate the influence of the model parameters on oxygen dynamics; demonstrate, that transient alleviation of tumor hypoxia occurs in a fairly wide range of physiologically justified values of parameters; and point out the major factors, that determine oxygen dynamics during antiangiogenic therapy.

Infection with Mycobacterium tuberculosis induces the Warburg effect in mouse lungs

To elucidate the little-known bioenergetic pathways of host immune cells in tuberculosis, a granulomatous disease caused by the intracellular pathogen Mycobacterium tuberculosis, we characterized infected murine lung tissue by transcriptomic profiling and confocal imaging. Transcriptomic analysis revealed changes of host energy metabolism during the course of infection that are characterized by upregulation of key glycolytic enzymes and transporters for glucose uptake, and downregulation of enzymes participating in the tricarboxylic acid cycle and oxidative phosphorylation. Consistent with elevated glycolysis, we also observed upregulation of a transporter for lactate secretion and a V type H(+) -ATPase involved in cytosolic pH homeostasis. Transcription profiling results were corroborated by immunofluorescence microscopy showing increased expression of key glycolytic enzymes in macrophages and T cells in granulomatous lesions. Moreover, we found increased mRNA and protein levels in macrophages and T cells of hypoxia inducible factor 1 alpha (HIF-1α), the regulatory subunit of HIF-1, a master transcriptional regulator. Thus, our findings suggest that immune cells predominantly utilize aerobic glycolysis in response to M. tuberculosis infection. This bioenergetic shift is similar to the Warburg effect, the metabolic signature of cancer cells. Finding immunometabolic changes during M. tuberculosis infection opens the way to new strategies for immunotherapy against tuberculosis.

The Regulation and Function of Lactate Dehydrogenase A: Therapeutic Potential in Brain Tumor

There are over 120 types of brain tumor and approximately 45% of primary brain tumors are gliomas, of which glioblastoma multiforme (GBM) is the most common and aggressive with a median survival rate of 14 months. Despite progress in our knowledge, current therapies are unable to effectively combat primary brain tumors and patient survival remains poor. Tumor metabolism is important to consider in therapeutic approaches and is the focus of numerous research investigations. Lactate dehydrogenase A (LDHA) is a cytosolic enzyme, predominantly involved in anaerobic and aerobic glycolysis (the Warburg effect); however, it has multiple additional functions in non‐neoplastic and neoplastic tissues, which are not commonly known or discussed. This review summarizes what is currently known about the function of LDHA and identifies areas that would benefit from further exploration. The current knowledge of the role of LDHA in the brain and its potential as a therapeutic target for brain tumors will also be highlighted. The Warburg effect appears to be universal in tumors, including primary brain tumors, and LDHA (because of its involvement with this process) has been identified as a potential therapeutic target. Currently, there are, however, no suitable LDHA inhibitors available for tumor therapies in the clinic.

Investigation of NK cell function and their modulation in different malignancies

NK cells have become a subject of investigation not only in the field of tumor immunology and infectious diseases, but also within all aspects of immunology, such as transplantation, autoimmunity, and hypersensitivity. Our early studies aside from investigating NK cell activity in experimental animals and humans included studies of perforin expression and modulation in this lymphocyte subset. As NK cell activity is modified by their environment, we showed clinical stage-dependent impairment of their activity and in vitro effect of different sera, Th1 cytokines, and their combination in breast cancer, Hodgkin's disease, and non-Hodgkin's lymphoma patients, especially with respect to metabolic and cell membrane changes of peripheral blood lymphocytes evaluated by spontaneous release of the enzyme lactate dehydrogenase (LDH) that led to the correction of the LDH enzyme release assay for natural cytotoxicity. By long-term immuno-monitoring of patients with malignancies, we also showed the kinetics of NK cell modulation during chemo-immunotherapy. In our more recent studies, we give data of NK function and novel families of NK cell receptor expression in healthy individuals that may be of help in NK cell profiling, by giving referent values of basic and cytokine-induced expression of some NK cell receptors either in evaluation of disease or in immuno-monitoring during cytokine therapy of patients with malignancies. Moreover, we give novel aspects of modulation of NK cell activity by cytokines approved for immunotherapy, IFN and IL-2, in melanoma and other malignancies with respect to alterations in new activating (NKG2D and CD161) and inhibitory (CD158a and CD158b) receptor characteristics and signaling molecules in CD16- and CD56-defined NK cells and their small immunoregulatory and large cytotoxic subsets in peripheral blood and lymph nodes, as NK cell-mediated killing of tumor cells depends on the balance between stimulatory and inhibitory signaling.

Relationships between edema degree and clinical and biochemical parameters in posterior reversible encephalopathy syndrome: a preliminary study

The objective of the study was to investigate the associations between the degree of edema with the clinical and biochemical parameters such as serum lactate dehydrogenase (LDH), albumin (ALB) in posterior reversible encephalopathy syndrome (PRES) patients. Forty-nine patients with typical clinical symptoms and characteristic MR imaging findings of PRES were included in this study. Lactate dehydrogenase and ALB were analyzed with the immunoluminometric assays. Fluid-attenuated inversion recovery images were used to evaluate the distribution of the extent or severity of vasogenic edema by two observers. Correlation analysis between the scores of brain edema and the blood pressures, clinical conditions and biochemical parameters was performed. No significant difference of brain edema score was found between patients with eclampsia, chronic renal failure and other clinical condition (P > 0.05). Both mean arterial pressures and LDH level were moderately correlated with the scores of brain edema distribution (Spearman's ρ test, r = 0.405 and 0.497, respectively, P < 0.01). Serum ALB level was not correlated with the scores of brain edema distribution (P > 0.05). Larger and more diffuse lesions may be predicted by higher LDH level and blood pressure. The overall severity of the systemic process might be predicted by the degree of edema expression in PRES.

The difference in lactate dehydrogenase activity between pre- and post-mobilization periods is a good indicator of successful stem cell mobilization

Predicting poor stem cell mobilization may prevent the costs and complications associated with remobilization. We retrospectively reviewed the relationship between serum lactate dehydrogenase (sLDH) activity and peripheral blood CD34 (PBCD34) cell counts in 46 granulocyte colony stimulating factor (G-CSF) induced mobilization cycles with or without chemotherapy. A significant correlation between post-mobilization (pre-apheresis) sLDH activity and PBCD34 count was found (r(s)=0.43, p=0.007). A strong correlation was shown between the pre- and post-mobilization sLDH activity difference and PBCD34 count (r(s)=0.55, p=0.001). With respect to sLDH activity differences; (a) all patients with a difference of >300 U/L, (b) 71% of patients with a difference of 100-300 U/L, and (c) 44% of patients with a difference of <100 U/L were considered to have good mobilizations. The sLDH activity difference between pre- and post-mobilization is a good indicator of successful mobilization. According to our results, the success of mobilization can be predicted based on sLDH activity differences; (i) good mobilization if the difference is >300 U/L, (ii) intermediate risk if the difference is 100-300U/L, and (iii) high risk if the difference is <100 U/L.

Prognostic significance of biochemical markers in African Burkitt's lymphoma

BACKGROUND AND PURPOSE Endemic Burkitt's lymphoma (eBL) remains the prevalent form of paediatric cancer in tropical Africa with subtle pathological differences. This calls for intensified efforts to validate the global prognostic markers within local settings for improved cancer treatment and survival. This study proposes prognostic markers for enhanced eBL treatment and management. PATIENTS AND METHOD One hundred and eighty histologically and/or clinically diagnosed BL patients at Komfo Anokye Teaching Hospital, Kumasi, Ghana were eligible for this cross-sectional eight-year retrospective study. Biochemical, clinical and demographic data, before chemotherapy administration, were documented and examined for their progression-free (PFS) and overall survival (OS) significance. RESULTS A mean age of 6 (SD=2.7, range: 1-16) years was observed with general male dominance (M:F=1.69:1). Total serum lactate dehydrogenase (HR=2.04; 95% CI, 1.25-3.32; log rank=8.3; p=0.004), serum creatinine (HR=3.59; 95% CI, 1.62-7.98; log rank=15.4; p=0.002) and St. Jude stage (HR=1.74; 95% CI, 1.11-2.73; log rank=8.0; p=0.015) were important independent prognostic biochemical markers for both PFS and OS. Age, serum calcium, uric acid, potassium, sodium and phosphorus were non-prognostic. CONCLUSION The better monitoring of these prognostic indices coupled with risk-stratification treatment may improve patients' survival, especially in resource-limited settings.

Influence of lactate dehydrogenase and cyclosporine A level on the incidence of acute graft-versus-host disease after allogeneic stem cell transplantation

Previous reports have suggested that a high serum cyclosporine A (CsA) level could result in a lower incidence of acute-graft-versus-host disease (aGVHD). An elevated serum lactate dehydrogenase (LDH) level has been reported to be an adverse predictor of outcome in stem cell transplantation (SCT) for acute myeloid leukemia. In this study, we retrospectively analyzed the records of 24 patients who received allogeneic SCT from an HLA-matched sibling donor for acute and chronic myelogenous leukemia. Univariate analysis showed that two factors (the serum CsA level at the third week after SCT and the LDH level at the third week after SCT) were significantly associated with the incidence of aGVHD among several variables (age, sex, stem cell source, cell dose, C-reactive protein, absolute lymphocyte count, conditioning regimens, and time to engraftment). A higher serum level of CsA and lower serum LDH level at the third week after SCT were associated with a lower incidence of aGVHD (P=0.015, 0.030). In multivariate analysis, the serum CsA level (hazard ratio [HR], 0.12; 95% confidence interval [CI], 0.022-0.652, P=0.0014) and serum LDH level (HR, 6.59; 95% CI, 1.197-36.316, P=0.030) at the third week after SCT were found to be independent factors that were significantly associated with the development of aGVHD. We conclude that a high CsA level and low LDH level might predict a low cumulative incidence of aGVHD after allogeneic transplantation from a matched sibling donor.

Correlation between serum lactate dehydrogenase and stem cell mobilization

After observing a correlation between elevated serum lactate dehydrogenase (LDH) levels and good stem cell collections, retrospective data from 540 donors undergoing 650 stem cell apheresis procedures (87% autologous, 13% allogeneic) were studied to determine the correlation between preapheresis LDH levels and the absolute peripheral blood CD34+ cell count (PBCD34). PBCD34 (1-1611/mul; median 40) correlated modestly with leukocytes (0.5-118.2 x 10(9)/l; median 30.2) (r=0.16; P=0.00005) and poorly with platelets (16-660 x 10(9)/l; median 131) (r=0.02; P=0.69). The correlation between LDH (64-1664 IU/l; median 310) and PBCD34 was very strong (r=0.54; P<10(-48)). In multivariate regression analysis, serum LDH was the only factor correlating significantly with PBCD34. The correlation between serum LDH and PBCD34 was strong on the first day of collection (n=517; r=0.53; P<10(-37)), weakened on the second day (n=74; r=0.37; P=0.0009) and disappeared beyond day 2 (n=59; r=0.09; P=0.49). PBCD34 was significantly higher (median 53 versus median 11; P<0.00001) when LDH was elevated (n=511) compared to when LDH was normal (n=139). The relationship between serum LDH and PBCD34 was strong for autologous (r=0.54) as well as for allogeneic (r=0.41) collections. Our data suggest that it is reasonable to assume good stem cell mobilization and start apheresis if the LDH is elevated.

Gender and age-related differences in Burkitt lymphoma--epidemiological and clinical data from The Netherlands

Although Burkitt's lymphoma (BL) is classified as one entity in the World Health Organisation (WHO) classification, we wondered whether BL should not be considered as a different disease in children compared with adults. Netherlands Cancer Registry (NCR) data were obtained from 1994 to 1998 (n=203). Detailed clinical data from two treatment protocols were compared: one for adults up to the age of 65 years (n=27) and one for children (n=80). All slides of the two clinical studies were centrally reviewed which included immunophenotyping and when necessary breakpoint analysis of MYC/8q24. Only cases with an unambiguous diagnosis of BL (classical and atypical BL) were accepted. The age distribution of BL-patients showed a bimodal distribution with a peak at the paediatric age and a steady increase after approximately 60 years of age. Most of the patients were males (89% for children and 78% for adults) and only male patients showed this bimodality. Children more often had extranodal disease (81% vs. 59%), whereas adults more often had nodal disease (89% vs. 53%). Based on epidemiology and clinical presentation, the concept that BL is one disease should be re-challenged.

Biochemical changes in the efferent lymph plasma after oxazolone stimulation

The lymph node is a specialized microenvironment for the regulation of immune responses. The reticular network of the lymph node provides a structure that facilitates not only intercellular interactions, but the intranodal flow of lymph fluid. To assess biochemical changes in the nodal lymph plasma after antigen stimulation, prescapular lymph nodes in sheep were stimulated with the epicutaneous antigen oxazolone. The efferent lymph from both antigen-stimulated and contralateral control prescapular lymph nodes was continuously monitored for more than 120 h. The oxazolone-stimulated lymph plasma was associated with a selective increase in cholesterol content during the 'recruitment' phase of lymph node enlargement. The peak in cholesterol was followed closely by a significant increase in lymph plasma LDH concentration. In contrast, there was no significant difference between oxazolone-stimulated and control lymph plasma in the concentration of triglycerides, albumin, alkaline phosphatase, and alanine transferase. These selective biochemical changes in the efferent lymph appeared to reflect the dynamics of lymphocyte activation within the lymph node as well as provide a practical measure of the lymph node response to antigen stimulation.

Association of NK cell dysfunction with changes in LDH characteristics of peripheral blood lymphocytes (PBL) in breast cancer patients

The cytotoxic activity of NK (natural killer) cells is very important in immunological surveillance against the appearance and especially the spread of malignant disease. The aim of this study was to investigate the function of this subpopulation of cells in breast cancer patients in different clinical stages of disease prior to therapy. NK cell activity was determined in breast cancer patients and healthy controls by three different methods: standard 51-chromium-release assay and by the original colorimetric uncorrected and corrected lactate dehydrogenase (LDH) release assay. A discrepancy was shown between the assays, as the uncorrected LDH assay showed, not only, much higher values, but no stage-dependent depression in NK cell activity compared to the chromium-release assay. Further analyses of separately cultured peripheral blood lymphocytes (PBL) revealed that this difference arose from an increasing, clinical stage-dependent, spontaneous LDH release from PBL of breast cancer patients. Furthermore, a stage-dependent increase in intracellular LDH activity of PBL was found, although without difference in LDH-H and LDH-M isotype ratio, compared to controls. Increased spontaneous LDH release and intracellular LDH activity was more evident in young patients, under 40 years. Correction of the original LDH-release assay for the spontaneous LDH release activity from PBL present in the assay, gave values of NK cell activity comparable to those determined by the chromium assay and indicated that breast cancer patients have a significant depression in NK cell activity which correlates with the stage-dependent increase in spontaneous LDH release. Moreover, as both assays measure the secretory, perforin-mediated, NK cell cytotoxic pathway against tumor cells, it can be concluded that the appearance of spontaneous LDH release is an indicator of cell membrane damage which not only allows the loss of LDH, but also of the components of the secretory killing pathway, resulting in NK cell dysfunction with the progression of disease. The novel findings obtained in this work reveal the association of PBL membrane damage with clinical stage of breast cancer that can, aside from reflecting NK cell depression, underlie the defect in other PBL subsets and subsequently facilitate progression of the malignant process.

Laboratory abnormalities in former blood donors seropositive for human T-lymphotropic virus types 1 and 2: a prospective analysis

CONTEXT

The human T-lymphotropic viruses types 1 and 2 (HTLV-1 and HTLV-2) are highly prevalent among injection drug users in the United States. However, the clinical course of infection has not been well characterized.

OBJECTIVE

To understand HTLV-1-and HTLV-2-associated laboratory abnormalities, which may provide insights into their underlying pathophysiology.

DESIGN

Cohort study.

SETTING

Five US blood centers.

PARTICIPANTS

A total of 133 HTLV-1-and 332 HTLV-2-seropositive former blood donors and 717 HTLV-seronegative donors followed up prospectively since 1991.

MAIN OUTCOME MEASURES

Selected serum chemistry tests and complete blood cell counts were analyzed at enrollment and approximately 2 years later in participants. Repeated-measures analyses were conducted to evaluate the effect of HTLV infection on laboratory measures.

RESULTS

Compared with seronegative subjects, HTLV-1-seropositive subjects had 13% higher creatine kinase (P =.02) and slightly elevated lactate dehydrogenase (P =.03) levels at follow-up. The HTLV-2-seropositive participants had 11% higher absolute lymphocyte counts than seronegative subjects (P =.0001). Infection with HTLV-2 also appeared to be associated with slightly higher hemoglobin levels (P =.03) and hematocrit (P =.03) and with lower albumin levels (P =.01).

CONCLUSIONS

These results further our understanding of the biological mechanisms underlying HTLV and suggest that HTLV-associated laboratory changes are unlikely to alter clinical evaluation or counseling of otherwise healthy HTLV-infected subjects.

The difference in NK-cell activity between patients with non-Hodgkin's lymphomas and Hodgkin's disease

Natural killer (NK) cells play an important role in immune surveillance against malignant diseases. Considering the lymphoid origin of malignant lymphomas, as well as scarce data concerning NK-cell function in these neoplasms, we evaluated NK-cell activity in 49 patients with non-Hodgkin's lymphomas (NHL) and 47 patients with Hodgkin's disease (HD), prior to therapy. Using the recommended International Working Formulation and the Ann Arbor staging system for classification of lymphomas we found, by the LDH release cytotoxicity assay, that decreased NK-cell activity (P < 0.05) in NHL patients was essentially related to unfavourable histology (13 indolent lymphomas, 25 intermediate and 11 very aggressive lymphomas were included), but that within these categories clinical stage of the disease also contributed to the degree of NK-cell dysfunction. In contrast, in HD, NK-cell activity was persistently decreased (P< 0.05), compared to controls, irrespective of histological type and clinical stage. It is of interest also that the most profound NK-cell dysfunction that is present and persistent from the onset of HD, and which appears in very aggressive NHL was associated with the phenomenon of increased spontaneous lactate acid dehydrogenase (LDH) release activity from the separated PBMC of these patients. The difference in the level of NK-cell impairment between patients with various histological grades of malignancy in NHL and HD suggests different initial participation of innate immune reactions in these diseases.

Oncogenes in tumor metabolism, tumorigenesis, and apoptosis

The ability of cancer cells to overproduce lactic acid aerobically was recognized by Warburg about seven decades ago, although its molecular basis has been elusive. Increases in glucose transport and hexokinase activity in cancer cells appear to account for the increased flux of glucose through the cancer cells. Herein we review current findings indicating that the c-Myc oncogenic transcription factor and hypoxia-inducible factor 1 (HIF-1) are able to bind the lactate dehydrogenase A promoter cis acting elements, which resemble the core carbohydrate response element (ChoRE), CACGTG. These and other observations suggest that the normal cell responds physiologically to changes in oxygen tension or the availability of glucose by altering glycolysis through the ChoRE, which hypothetically binds c-Myc, HIF-1, or related factors. The neoplastic cell is hypothesized to augment glycolysis by activation of ChoRE/ HIF-1 sites through direct interaction with c-Myc or through activation of HIF-1 or HIF-1-like activity. We hypothesize that oncogene products either stimulate HIF-1 and related factors or, in the case of c-Myc, directly activate hypoxia/glucose responsive elements in glycolytic enzyme genes to increase the ability of cancer cells to undergo aerobic glycolysis.

Regulated, stable expression and nuclear presence of reovirus double-stranded RNA-binding protein sigma3 in HeLa cells

Reovirus genome segment S4 codes for polypeptide sigma3, a major outer capsid component of virions and a double-stranded RNA (dsRNA)-binding protein implicated in viral cytopathogenesis. We have constructed a stable HeLa cell line (S4tTA) that produces functional sigma3 under tetracycline transactivator control. In the absence of tetracycline, S4tTA cells synthesized stable dsRNA-binding sigma3 that accumulated in the nucleus as well as in the cytoplasm. However, in induced S4tTA cells also expressing reovirus outer shell polypeptide mu1/mu1C, migration of sigma3 into the nucleus was blocked, probably as a result of formation of a complex with mu1/mu1C which was exclusively in the cytoplasm. Mutant analyses indicated a correlation between dsRNA-binding activity and nuclear entry of sigma3, suggesting an additional role(s) for this capsid protein in virus-cell interactions.

Serum levels of tumour necrosis factor-alpha in patients with B-cell chronic lymphocytic leukaemia

Serum levels of tumour necrosis factor-alpha (TNF-alpha) have been evaluated in the peripheral blood of 91 patients with B-cell chronic lymphocytic leukaemia (B-CLL), and have been correlated with the clinical stage (according to Rai's staging system) and relevant haematological and immunological data. Increased values were detected, compared to 36 normal age-matched controls (36 pg/ml +/- 5 versus 0.11 pg/ml +/- 0.08; P < 0.05). An increase of TNF-alpha serum levels was observed in all stages including stage 0, with a progressive increase in relation to the stage of the disease. A significant relationship between serum TNF-alpha levels and the number of circulating monocytes (P < 0.002) and an inverse correlation with the level of the haemoglobin (P < 0.001) was established, as defined by the Pearson's correlation test. In contrast, no correlation was observed between TNF-alpha serum levels and the other parameters taken into account, including the white blood cell and platelet counts, the absolute number of peripheral blood (PB) lymphocytes, CD5+ B lymphocytes, CD57+ lymphocytes, serum levels of lactic dehydrogenase, total serum immunoglobulins and the serum levels of IgG, IgA and IgM. These data suggest that, in addition to the B-CLL neoplastic cells, the PB monocytes may be involved in the release of TNF-alpha.