A complementary role of multiparameter flow cytometry and high-throughput sequencing for minimal residual disease detection in chronic lymphocytic leukemia: an European Research Initiative on CLL study.

In chronic lymphocytic leukemia (CLL) the level of minimal residual disease (MRD) after therapy is an independent predictor of outcome. Given the increasing number of new agents being explored for CLL therapy, using MRD as a surrogate could greatly reduce the time necessary to assess their efficacy. In this European Research Initiative on CLL (ERIC) project we have identified and validated a flow-cytometric approach to reliably quantitate CLL cells to the level of 0.0010% (10(-5)). The assay comprises a core panel of six markers (i.e. CD19, CD20, CD5, CD43, CD79b and CD81) with a component specification independent of instrument and reagents, which can be locally re-validated using normal peripheral blood. This method is directly comparable to previous ERIC-designed assays and also provides a backbone for investigation of new markers. A parallel analysis of high-throughput sequencing using the ClonoSEQ assay showed good concordance with flow cytometry results at the 0.010% (10(-4)) level, the MRD threshold defined in the 2008 International Workshop on CLL guidelines, but it also provides good linearity to a detection limit of 1 in a million (10(-6)). The combination of both technologies would permit a highly sensitive approach to MRD detection while providing a reproducible and broadly accessible method to quantify residual disease and optimize treatment in CLL.

Detecting minimal residual disease in patients with chronic lymphocytic leukemia using 8-color flow cytometry protocol in routine hematological practice.

INTRODUCTION: Minimal residual disease (MRD) detection has become increasingly important for the assessment of therapy response in chronic lymphocytic leukemia (CLL). However, current MRD analysis methods, both molecular genetic and flow cytometric, are time-consuming and require experienced laboratory staff. METHODS: To reduce the demands of flow cytometric MRD detection in CLL, we have introduced a novel flow cytometric 8-color protocol. The MRD analysis results using this protocol were then compared with the commonly employed 4-color protocol and the molecular genetic (real-time quantitative allele-specific oligonucleotide IGH polymerase chain reaction; RQ-ASO IGH PCR) approach. RESULTS: Forty-two CLL patient samples were repeatedly analyzed after allogeneic stem cell transplantation (n = 20) or after fludarabine-based therapy (n = 22), and 100% concordance was found using both flow cytometric protocols. Furthermore, there was a strong correlation (r = 0.94) between flow cytometric and RQ-ASO IGH PCR results in MRD detection. CONCLUSION: Flow cytometry is less time-consuming, less financially demanding, and moreover, MRD assessment using our novel 8-color protocol is less complicated than the 4-color approach and molecular methods.

[Our experience in treatment of multicentric plasma-cell Castleman disease associated with vasculitis manifestations - case report and literature review]. / Nase zkusenosti s lécbou multicentrické plazmocelulární Castlemanovy choroby s projevy vaskulitidy - popis prípadu a prehled literatury.

Castleman disease is a rare idiopathic non-neoplastic lymphoproliferative disorder with 2 clinical (unicentric and multicentric) and 3 histomorphological (hyaline-vascular, plasma-cell and mixed) forms identified. The case report given here describes the 3-year experience with therapy in a patient, male born 1961, diagnosed with multicentric plasma-cell Castleman disease (HIV and HHV-8 negative) with the finding of generalized lymphadenopathy and splenomegaly. During first line treatment (R-CHOP: rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone, 3 cycles in total, 12/2008-2/2009) the development of bilateral upper and lower limb edemas with clinical manifestation of vasculitis occurred and a restaging computed tomography (CT) examination revealed a stable finding of the lymphadenomegaly. Greater success was achieved with thalidomide regimen (CTD: cyclophosphamide, thalidomide, dexamethasone, 10 cycles, 3/2009-1/2010) leading to reduction in the size of the hypervascularized lymph nodes (almost by 50%) as well as their radiopharmaceutical (fluorodeoxyglucose) uptake as seen on a combined positron emission tomography and computed tomography (PET/CT) scan imaging. Thalidomide was given daily at doses between 100 and 200 mg. We returned to the CTD regimen again in April 2010 after a short period of monoclonal antibody tocilizumab treatment (400 mg intravenous in 2-week intervals with 50% dose reduction due to a limited supply of the drug, 5 doses in total) during which edemas reoccurred with a CT scan finding of stable lymphadenomegaly. However, the renewed regimen with thalidomide was stopped after 2.5 cycles due to adverse effects of thalidomide (neuropathy) and corticoids (Cushing syndrome). In September 2010, after enrollment in the Celgenes Compassionate Use Program we were able to start treating the patient with the derivative of thalidomide, lenalidomide, at a dosage of 25 mg on days 1-21 in a 28-day cycle, 15 cycles in total (10/2010-12/2011). The monotherapy with lenalidomide was very well tolerated by the patient without any effects of myelotoxicity, thromboembolism or relapses of edemas and vasculitis, additionally now with apparent improvement of fatic disorder and the patients motor abilities. Thus, lenalidomide represents an attractive alternative agent for patients with Castleman disease after rituximab and cytostatics failures. It has a favourable safety profile and could be therefore considered for administering in first line treatment.

[Schnitzler syndrome: case report, the experience with glucocorticoid and anakinra (Kineret) therapies and monitoring of systemic cytokine response]. / Schnitzler-syndrom: popis prípadu, zkusenosti s lécbou glukokortikoidy a preparátem anakinra (Kineret) a sledování cytokinové odpovedi organizmu.

Schnitzler syndrome is a rare idiopathic disease characterized by chronic urtica, presence of monoclonal IgM immunoglobuline and further, less common symptoms. This case report describes another case of this disease affecting a male adult born in 1963. The first symptoms, eruptions of non-pruritic urticarial rash, appeared in this patient at the age of 43. In addition, bone pains (mainly tibias) and joint pains (mainly knees) were present. Later on however, severe attacks of fever, chills and shaking together with bone and joint pains were added to during which new urticarial eruptions appeared. Primarily, the man was followed up without any substantial therapeutic results at a department of dermatovenerology, subsequently, due to a finding of monoclonal IgM kappa immunoglobulin (serum concentration 1.9 g/l) he was referred to our department for the reason of gammopathy being a differential diagnosis. On a CT scan hyperostosis in claviculae and pelvic bones was identified. Also on the CT, an increase in cortical thickness was described in the long bones of the lower extremities, where areas of technetium pyrophosphate accumulation were identified on a bone scintigraphy. These areas were found in the chest and sacral regions as well. From the blood exams, the proinflammatory status of the organism was apparent (CRP 35.9 mg/l, erythrocyte sedimentation rate 92 mm/h, leukocytes 12.4 x 10(9)/l). After excluding other differential diagnoses, the patient was diagnosed with Schnitzler syndrome. As regards therapy, we made initial use of the effect of corticoids which abated the symptoms, however, these were causing serious adverse reactions in the form of iatrogenous Cushing's syndrome. The therapy took a turn only after biologic therapy with anakinra (interleukin-1 receptor antagonist) had started, which minimized the Schnitzler symptoms with very good drug tolerance. In the work we measured serum levels of interleukins for disease activity monitoring. The most sensitive were interleukins IL-6 and especially IL-18 the levels of which were the highest at the time of clinical exacerbation of the disease, whereas the levels of IL-1beta and TNF-alpha (tumour necrosis factor) were during all measurements below the limit of detection. Concerning the growing numbers of the reports on successful biological therapy with anakinra and our positive experience, we propose that the therapeutic response to anakinra should be included within the diagnostic criteria of Schnitzler syndrome, which is significant above all in differential diagnosis thereof.

Interlaboratory variability of CD34+ stem cell enumeration. A pilot study to national external quality assessment within the Czech Republic.

We present the results of a pilot study concerning the interlaboratory variability of CD34+ enumeration. Three surveys, each including a set of samples, were sent to participating Czech flow cytometry laboratories. The efficacy of this exercise was determined by the reduction in interlaboratory variation and the influence of method used on assay outcome. The variability in results of CD34+ enumeration declined with time. The mean coefficient of variation (CV) of measurement among laboratories dropped, from 58% in first survey to 32% in last survey. All tested variables (gating strategy, platform methodology, sample preparation) affected the variability of the assay. Sample preparation method was associated with a significant bias of absolute CD34+ cell counts. Initially, the outcome of the measurement was also affected by the participating laboratory (identified by a unique laboratory number; ULN). However, laboratories with poorer performance modified their protocols during the study, and the ULN ceased to influence the variability. This study was successful in reducing the interinstitutional variability of CD34+ enumeration. It was shown that the implementation of a standardized protocol does not guarantee accurate measurement. Our research design represents a useful tool, which allows verification of the proper use of a standardized method, the training of operators and feedback in response to the survey results.