Zdeněk Pospíšil

Pulse cyclophosphamide for corticosteroid-refractory graft-versus-host disease.

Summary:Corticosteroid-resistant GVHD is difficult to manage and is associated with high morbidity and mortality. Cyclophosphamide (Cy) is an established immunosuppressive and cytotoxic drug widely used as part of pretransplant conditioning regimens. In a retrospective study of 15 patients who had not responded to corticosteroids (nine with acute GVHD, three with GVHD after donor leukocyte infusion, and three progressive chronic GVHD), pulse Cy at a median dose of 1 g/m2 was very effective in the treatment of skin (100% response), liver (70% response), and the oral cavity (100% response). Severe intestinal GVHD responded poorly. The toxicity profile was acceptable, with manageable, short-term myelosuppression in some patients. The risk of opportunistic infections, mixed chimerism, relapses, or post-transplant lymphoproliferative disease was not increased. Overall survival was 57%, with median and maximum follow-up of 9 and 37 months, respectively. The cost of the drug was negligible, especially when compared to monoclonal antibodies. Pulse Cy requires further investigation in corticosteroid-resistant GVHD.

Modern and conventional prognostic markers of chronic lymphocytic leukaemia in the everyday haematological practice

Objectives: The impact of modern prognostic markers on clinical course of chronic lymphocytic leukaemia (CLL) in everyday practice has been not yet well defined, especially in large series of patients. Therefore, the goal of this study was to assess the influence of conventional as well as modern prognostic factors on overall survival (OS) and time to therapy (TTT) of patients with CLL. Methods: We retrospectively analysed data of all patients consecutively entered into the databases of five large academic centres in the Czech Republic. The total of 1300 patients was included in the analysis. Results and conclusion: Through the use of uniparametric analysis, it was determined that gender, clinical stage Rai II–IV, unmutated IgVH status, deletion 17p (for both 5% and 20% cut‐off), deletion 11q, ZAP‐70 positivity and high expression of CD38 had significant negative influence on OS. TTT was significantly influenced by gender, Rai stage, IgVH status, deletion 11q, deletion 17p, deletion 13q and CD38 expression. Multiparametric analysis revealed that OS was significantly influenced by gender, age, IgVH status and deletion 17p. If only patients who died of CLL were included, gender, age, Rai stage, IgVH status and deletion 17p had significant influence on OS. Based on our results, the examination of biological prognostic markers can give an insight into the possible disease evolution in daily clinical practice. Biological prognostic markers are, however, not ready (maybe except deletion 17p in younger patients) to be used for guidance of therapy at least outside of clinical trials.

Constant BCR-ABL transcript level ≥0.1% (IS) in patients with CML responding to imatinib with complete cytogenetic remission may indicate mutation analysis

OBJECTIVE Of 140 chronic myeloid leukemia patients responding to imatinib with complete cytogenetic remission, 32 exhibited a plateau of BCR-ABL values at >or=0.1% level in a minimum of three subsequent samples (minimal duration, 6 - 9 months). Median follow-up of unchanged BCR-ABL transcript level was 12 months (range, 6 - 64). We tested this group of patient for BCR-ABL mutations to reveal resistance development and to evaluate the risk of disease progression. MATERIALS AND METHODS Altogether, 134 samples of peripheral blood of these 32 patients were tested for mutation in BCR-ABL kinase domain. RESULTS Mutation was detected by direct sequencing in 9 of 32 patients (28%). Loss of complete cytogenetic remission or 1 log rise of BCR-ABL was observed in five of nine patients at a median of 5 months (range, 4-17) since first detection of mutation. One patient with no mutation relapsed 12 months after the start of the BCR-ABL plateau. In 5 of 32 patients without mutation (16%), BCR-ABL level significantly decreased after the first plateau to levels that stayed unchanged for a median of 11 months (range, 7-28). CONCLUSION We show here that the BCR-ABL constant levels >or=0.1% (BCR-ABL plateau) in imatinib-responding patients may indicate mutation analysis. This approach highly reduces the number of examinations for mutation in chronic myeloid leukemia responders and may present cost-effective alternative applicable in clinical practice.

Phytophagous and predatory mites (Acari: Tetranychidae, Eriophyidae, Phytoseiidae, Stigmaeidae) in South Moravian vineyards, Czechoslovakia, treated with various types of chemicals

Communities of phytophagous and predatory mites on vine can be influenced by the type of chemical treatment. Ten species of phytoseiid mites inhabit vines in the region of South Moravia. Populations ofTyphlodromus pyri Scheuten play leading roles in effective suppression of tetranychid and eriophyid mites in commercial vineyards sprayed with pesticides, except synthetic pyrethroids and mancozed, which are considered to be detrimental to the predatory phytoseiid mites.

Clinical outcomes and direct hospital costs of reduced-intensity allogeneic transplantation in chronic myeloid leukemia

A reduced-intensity conditioning allogeneic stem cell transplantation was given to 19 patients (aged 15–59 years) in the first chronic phase and one patient in the accelerated phase with chronic myeloid leukemia (CML) after a regimen consisting of fludarabine (Flu), busulfan (Bu) and ATG Fresenius. The median follow-up was 27 months. Until day +100, no transplant-related mortality was recorded. The incidence of acute and chronic graft-versus-host disease (GvHD) was 55 and 75%, respectively. Two patients (10%) died from GvHD. Fourteen (70%) patients achieved molecular remission. Additional post-transplant intervention (donor lymphocyte infusion, imatinib) was necessary, however, in 10 patients (50% of the patients; non-achievement of stable molecular remission or later relapses). The total direct cost of the transplantation treatment for all of the patients came to 1 572 880 euro. If the patients had been treated with imatinib and followed-up with the same time period as they were following a transplantation, the direct cost of the imatinib treatment would have been 2 005 117 euro. The transplantation treatment appears to be less expensive after approximately 2 years of follow-up. Flu+Bu+ATG is a low-toxicity regimen for patients with CML. However, a close follow-up is necessary and about 50% of the patients require further therapeutic intervention.

The mechanism of erythrocyte sedimentation in Westergren’s examination

The authors deduced the equation that describes the sedimentation of erythrocytes as the function of time, hematocrit, hemoglobin and some plasma protein concentrations and the citrate viscosity and density. This values served to describe plasma and erythrocyte density, plasma viscosity, erythrocyte aggregation and the influence of suspension concentration on the erythrocyte sedimentation rate. The influence of citrate on blood dilution (the reduction of hematocrit and plasma protein concentrations) was also considered. A good agreement between the observed and predicted values was obtained.

Estimation of current cumulative incidence of leukaemia-free patients and current leukaemia-free survival in chronic myeloid leukaemia in the era of modern pharmacotherapy

BackgroundThe current situation in the treatment of chronic myeloid leukaemia (CML) presents a new challenge for attempts to measure the therapeutic results, as the CML patients can experience multiple leukaemia-free periods during the course of their treatment. Traditional measures of treatment efficacy such as leukaemia-free survival and cumulative incidence are unable to cope with multiple events in time, e.g. disease remissions or progressions, and as such are inappropriate for the efficacy assessment of the recent CML treatment.MethodsStandard nonparametric statistical methods are used for estimating two principal characteristics of the current CML treatment: the probability of being alive and leukaemia-free in time after CML therapy initiation, denoted as the current cumulative incidence of leukaemia-free patients; and the probability that a patient is alive and in any leukaemia-free period in time after achieving the first leukaemia-free period on the CML treatment, denoted as the current leukaemia-free survival. The validity of the proposed methods is further documented in the data of the Czech CML patients consecutively recorded between July 2003 and July 2009 as well as in simulated data.ResultsThe results have shown a difference between the estimates of the current cumulative incidence function and the common cumulative incidence of leukaemia-free patients, as well as between the estimates of the current leukaemia-free survival and the common leukaemia-free survival. Regarding the currently available follow-up period, both differences have reached the maximum (12.8% and 20.8%, respectively) at 3 years after the start of follow-up, i.e. after the CML therapy initiation in the former case and after the first achievement of the disease remission in the latter.ConclusionsTwo quantities for the evaluation of the efficacy of current CML therapy that may be estimated with standard nonparametric methods have been proposed in this paper. Both quantities reliably illustrate a patients disease status in time because they account for the proportion of patients in the second and subsequent disease remissions. Moreover, the model is also applicable in the future, regardless of what the progress in the CML treatment will be and how many treatment options will be available, respectively.

Hazard function for cancer patients and cancer cell dynamics

The aim of the paper is to develop a procedure for an estimate of an analytical form of a hazard function for cancer patients. Although a deterministic approach based on cancer cell population dynamics yields the analytical expression, it depends on several parameters which should be estimated. On the other hand, a kernel estimate is an effective nonparametric method for estimating hazard functions. This method provides the pointwise estimate of the hazard function. Our procedure consists of two steps: in the first step we find the kernel estimate of the hazard function and in the second step the parameters in the deterministic model are obtained by the least squares method. A simulation study with different types of censorship is carried out and the developed procedure is applied to real data.

Mathematical model of peripheral blood stem cell harvest kinetics

Summary:A mathematical model of peripheral blood stem cell harvests was developed, taking two new parameters R (number of recruited cells/minute) and Ef (efficiency of collection) into consideration in addition to concentrations and collected amounts of cells. This model was tested on 241 harvest procedures in cancer patients (chemotherapy+G-CSF stimulation), donors of allogeneic PBSC, and platelet donors, using different collection procedures, with a Cobe Spectra Cell separator. The relationships between preapheresis concentrations, R, Ef and harvested amounts of cells were complex, and different for different harvest procedures and populations of donors. However, invariably, recruitment played an important role and contributed significantly to the final harvest in all types of cells studied. For example, for the patient group, mean recruitment was 1.3 × 106 CD34+ cells/min and the amount of recruited cells corresponded to 65% of all collected cells. Recruitment was significantly influenced by pretreatment with chemo-therapy and/or radiotherapy. The mean recruitment values for the subgroups with limited, moderate, and extensive pretreatment were 1.65 × 106, 0.87 × 106, and 0.32 × 106 CD34+ cells released per minute, respectively. The finding of a quick and massive recruitment phenomenon may stimulate further research into hematopoiesis in order to maximize harvested cells.

Kinetics of bilirubin and liver enzymes is useful for predicting of liver graft-versus-host disease

Graft-versus-host disease (GVHD) is the most frequent complication after allogeneic hematopoietic cell transplantation. We analyzed the kinetics of bilirubin and liver enzymes in 47 cases with liver GVHD and in 47 cases without GVHD after allogeneic transplantation for various hematological malignancies. The duration of an liver GVHD episode (LGVHD) was defined as the interval from the point when the criteria of LGVHD were met to the decrease to < 2 upper normal limit (UNL) for aminotransferases or bilirubin < 34 μmol/l for bilirubin. The imminent LGVHD episode was defined as the interval from the start of continuous increase (≥ 3 consecutive rising values) of bilirubin and liver enzymes above UNL to the point of LGVHD diagnosis.The number of imminent LGVHD episodes, and median length in days were as follows: bilirubin (39;5), ALT(28;12), AST(9;12), GGTP(34;9), and ALP(13;14). Statisticallly significant associations between asymptomatic continuous increase of bilirubin, ALT, and GGTP and later liver GVHD manifestation were found (p=0.004, p=0.008, p=0.005, respectively). The asymptomatic continuous increase in bilirubin, ALT, and GGTP occurred at a median of 5, 12, and 9 days before liver GVHD episode, respectively. In the control group without GVHD, median levels of bilirubin and liver enzymes were within normal limits and no continuous increase was observed.Kinetics of bilirubin and liver enzymes is useful for predicting of liver GVHD. A continuous increase of bilirubin and/or ALT, GGTP before the standard liver GVHD criteria are met can be a sign of coming liver GVHD.