T-cell Subset Profile in Kidney Recipients of Extended or Standard Donors.

INTRODUCTION: The usage of extended-criteria donors (ECD) became a routinely accepted manner in the last decade. ECD is a potential risk factor for antibody-mediated rejection. Analysis of lymphocyte subsets might be a complementary diagnostic toolkit because there is limited knowledge about this term. METHOD: Between May 12, 2016, and September 4, 2019, a total of 130 patients who had undergone kidney transplant were investigated. Patients were divided in ECD and standard criteria donor (SCD) groups. Blood samples were collected before the operation, then in the first week and after 30, 60, 180, and 365 days. Besides routine laboratory tests, multicolor flow cytometry was performed for lymphocyte subsets. RESULTS: ECD grafts were transplanted to older recipients. The number of CD4+ cells increased in the SCDs from the first week to until the end of first month, and then decreased. The number of CD4+ cells decreased from the beginning of the study until the end of first year to 66% of its original value in ECDs. At the first month, the number of CD19+ cells was higher in SCD compared with ECD cases; the number then decreased in both groups. T-regulatory cells had a drop at the first week that lasted until the first month. A bigger increase in SCD and a moderate increase in ECD group were then observed. The kinetics of CD19+ and CD19+ naive cells are similar in the ECD and SCD groups. In the SCD group, cell count decreased in both CD19+ (13%) and CD19+ naive (12%) between third and sixth month. The count of CD19+ cells decreased by 9%, but the count of CD19+ naive cells increased by 11% between the sixth month and first year. DISCUSSION: The prolonged postoperative uremic state caused by the poorer initial function, together with an aging immune system, explains the weaker immune response in ECD patients, which may be the cause of the decreased number of memory and regulatory T cells. Older patients with an ECD graft need a tailored, personalized, and less aggressive immunosuppressive treatment.

T Cell Subset Profile and Appearance of Donor-specific Antibodies in Primary and Retransplanted Kidney Recipients.

INTRODUCTION: Accelerated antibody-mediated rejection is a major challenge after kidney transplantation. While the clinical course, diagnosis, and treatment of cell-mediated acute rejection is agreed upon and has been successfully performed, the antibody-mediated rejection remains a problem. Biopsies cannot be repeated several times, are not always representative, and are refused by many patients. Analysis of T-cell subsets and donor-specific antibodies (DSAs) might be an additive diagnostic tool in the case of kidney transplantation. METHOD: Between 2015 and 2017, 50 kidney transplant patients were enrolled in the study. Patients were divided into 2 clinical groups: primary transplants and regrafted patients. Serum samples were collected right before the operation, then in 1 week; 30, 60, and 180 days; and yearly. Besides routine laboratory, multicolor flow cytometry was performed for T cell subsets, and Luminex Single Antigen Bead assay for the detection on donor-specific anti-HLA antibodies. Medical data were also fixed. RESULTS: The percentage of CD4+ and CD8+ cells (the CD4+/CD8+ rate) did not change much over time in either group. The percentage of CD19+ cells increased until week 1, then decreased back to its original level by day 180. CD56+/3-% was high in both groups and had no characteristic kinetics by the time. The CD4+ naïve absolute cell count increased in first-time transplants and did not decreased back to its original value until the end of year 1. This is in contrast to retransplants, where CD4+ naïve cell count rapidly dropped below its original value and remained low throughout the first year after transplantation. The CD8+ effector memory absolute cell-count was higher in first-time transplants compared to retransplanted patients in all time points. By the end of month 1, the CD19+ naïve absolute cell-count increased in first-time transplants to 170% of its original value; however, it remained or decreased in second transplants. By the end of the first year, the CD19+ naïve absolute cell count diminished to 70% in first-time transplants and 38% in second transplants. DSA was detected in 9 out of the 38 first-time transplants (23.7%) compared to 7 out of 12 (58.3%) in regrafted patients during the observational period (P = .001). It was typical for regrafted patients for DSAs to appear earlier after transplantation, and that more simultaneously different antibodies were detected against more antigens at the first time point compared to first-time transplants. DISCUSSION: The 2 groups were similar in demographics and there were no differences regarding the clinical course, complications, or output data. However, we found statistical differences regarding the dynamics of T cell subsets and DSAs. The parallel measurement of CD subsets and DSAs might be a sensitive and useful additive tool in diagnosing subclinical immunologic changes after transplantation.

Flow Cytometry in the Diagnosis of Myelodysplastic Syndromes.

Myelodysplastic syndromes are clonal hematopoietic stem cell disorders. Their exact etiology is unknown. Myelodysplastic syndromes cause progressive bone marrow failure resulting in pancytopenia and refractory, transfusion-dependent anemia. One can observe typical morphological alterations in the erythroid, myeloid and/or megakaryocytic cell lineage. Blast counts may also be increased. The pathologic cells are genetically unstable, and a myelodysplastic syndrome might transform into acute myeloid leukemia. The overall survival of these diseases range between few months to around ten years. Correct diagnosis and accurate prognostic classification is essential. In the past decades several scoring systems were established beginning with the French-American-British classification to the most recent Revised International Prognostic Scoring System. In all of these classifications bone marrow morphology is still the most important factor, though nowadays the genetic aberrations and flow cytometry findings are also included. The diagnosis and prognostic classification of myelodysplastic syndromes remain a great challenge for hematologists.

Prediction of Therapy Response and Prognosis in Leukemias by Flow Cytometric MDR Assays.

Multidrug resistance (MDR) is an unwanted phenomenon, that may cause therapy failure in several neoplasms including hematological malignancies. The purpose of any type of laboratory MDR assay is to reliably identify such patients and to provide useful data to clinicians with a relatively short turnaround time. MDR can be multicausal and several previous data identified a group of transmembrane proteins - the ATP-binding casette (ABC) proteins - that may be involved in MDR in various hematological malignancies. The prototype of these proteins is the P-glycoprotein (Pgp, MDR1, ABCB1) that is a seven-membrane spanning transmembrane protein capable of extruding several cytotoxic drugs that are of key importance in the treatment of hematological disorders. Similarly other ABC proteins - Multidrug resistance associated protein 1 (ABCC1) and breast cancer resistance protein (ABCG2) are both capable of pumping out cytotoxic drugs. Here, we present flow cytometric methods to identify MDR proteins by antigen and activity assays. The advantage of flow technology is the short turnaround time and its relative easiness compared to nucleic acid based technologies. However, for the activity assays, it should be noted, that these functional tests require live cells, thus adequate results can only be provided if the specimen transport can be completed within 6 hours of sample collection. Identification of MDR proteins provides prognostic information and may modulate therapy, thus signifies a clinically useful information in the evaluation of patients with leukemias.

[Immunohistochemical demonstration of mutant nucleophosmin in acute myeloid leukemia: biological and clinical features related to NPMc expression]. / Mutáns nucleophosmin fehérje kimutatása akut myeloid leukaemiában: az NPMc+ AML biológiai és klinikai jellemzôi.

The mutation of the nucleophosmin gene (NPM1) is the most frequently occurring genetic aberration in acute myeloid leukemia (AML). Due to the high frequency and the obvious impact on disease outcome, the current WHO classification also defines the new (tentative) entity of "AML with NPM mutation". Mutations of NPM1 exon 12 affect both nuclear complexion and nuclear export signaling (NES) domain resulting in redistribution and accumulation of the NPM protein in the cytoplasm of leukaemic cells. The effect of gene mutation can be directly demonstrated by the occurrence of cytoplasmic NPM using immunohistochemistry (NPMc+). The present study focused on further biological and clinical characterization of NPMc+ AML determined by histological and cytological preparations of the bone marrow. 41 adult AML cases were investigated in our center between 2005 and 2008, 6/41 cases were presented with cytoplasmic NPM immunostaining (14.6%). All but one were female patients, and were diagnosed as de novo AML with no recurrent cytogenetic aberrations (6/23, 26.1%). The NPMc+ group displayed M2 or M4 morphology, low CD34, c-kit and HLA-DR expression making a clear phenotypic distinction from the unaffected cases possible. These results are in agreement with previous studies. In conclusion, immunohistochemistry is well applicable for the identification of NPM mutated AML in the daily hematopathology practice.

["Turnaround time": a new parameter for the characterization of the overall efficacy of laboratory diagnostic processes]. / "Turnaround time": a laboratóriumi eredménykiadás hatékonyságának új paramétere.

INTRODUCTION: The authors developed a special computer-aided routine in their laboratory for the calculation of "turnaround time" which parameter is suitable for the characterization of the overall efficacy of laboratory diagnostic processes. The turnaround time is defined as the interval between the arrival time of a sample in the laboratory and the time of clinical validation. It characterizes the efficacy of the result generation process very well, and therefore, is considered as an important parameter of laboratory quality control. METHODS: In their present study the authors analyzed the data of the urgent (stat), routine and special laboratory tests of 6 months and presented the median, 5- and 95-percentile values of turnaround time. Beside this, they calculated the rate of "outliers": the number of tests having a longer turnaround time value, than the defined maximal turnaround time (stat 1 hour, routine 4 hours, special 2-14 days). RESULTS: The median turnaround time values were 9-70 minutes for the stat tests and 33-190 minutes for the routine analytes. In case of special tests, the results were much more heterogeneous, in general non-automated hemostasis and immunochemistry assays, with low sample numbers had longer turnaround time values and higher number of outliers. Longitudinal analysis of routine tests showed clearly that turnaround time values became shorter in every unit during the 1st 6 months of 2006. Clinical validation is an important component altering turnaround time that can be shortened substantially with the installation of an autovalidation program. Based on the data of the authors the median turnaround time values of routine assays were shortened by 1-2 hours after introduction of autovalidation. The applied program for turnaround time analysis is suitable for evaluation of sample transfer times, too, that was presented by comparison of two "emergency units" having different sample transfer facilities. CONCLUSIONS: The described turnaround time analysis is part of the general routine processes in laboratories of the developed countries but is the first such trial in Hungary.

Mean fluorescence intensity rate is a useful marker in the detection of paroxysmal nocturnal hemoglobinuria clones.

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired disorder of the pluripotent stem cell resulting from the somatic mutation of the X-linked PIG-A gene, involved in the synthesis of the glycosylphosphatidyl-inositol anchor of membrane proteins such as CD55, CD59 and CD14. In the past decade, flow cytometry has become a valuable diagnostic tool in the detection of deficient expression of the GPI-anchored proteins. We report the diagnosis of PNH in four patients confirmed by flow cytometry. Red blood cells, granulocytes and monocytes were classified as PNH types I, II and III according to the mean fluorescence intensities (MFI) of membrane proteins. MFI rate is a numerical data reflecting the severity of decreased antigen expression, and it is obtained by dividing the MFI of the type II or type III cells by the MFI of the respective cells obtained for a normal sample. We found that the investigation of granulocytes and monocytes was more informative than red blood cells when percent negativity was evaluated. In addition, the lowest MFI rate (mean 0.011) was obtained for CD14 on monocytes while CD59 and CD55 gave higher values on all three investigated cell types (0.021-0.34). Thus, CD14 on monocytes seems to be the most reliable marker for establishing the PNH clone size and the severity of antigen deficiency.

The emerging value of P-selectin as a disease marker.

Activated platelets are key components in many arterial disorders. P-selectin is an activation-dependent platelet receptor, which is also identified in endothelial cells. Together with E- and L-selectin it constitutes the selectin family. These transmembrane proteins have continued to attract great interest as they support rapid and reversible cell adhesion in flow systems and thus play an essential role in multicellular interactions during thrombosis and inflammation. Similarly to other lectins, selectins bind to different glycoconjugates with varying affinities. Protein ligands, equipped with the appropriate carbohydrate and sulfate moieties for P-selectin binding, have been identified in normal peripheral blood leukocytes and several non-hematopoietic organs, as well as on cancer cells. For diagnostic purposes, P-selectin can readily be detected on the platelet surface by flow cytometry and by ELISA as a soluble ligand in the plasma. Along with other markers, these data can be used in the assessment of platelet activation status. Such results bear clinical significance since P-selectin has been implicated in the pathogenesis of wide-spread disorders including coronary artery disease, stroke, diabetes and malignancy.

Progress in defining multidrug resistance in leukemia.

Multidrug resistance (MDR) is a naturally occurring defense phenomenon by which cells battle against chemically foreign substances (xenobiotics), including some cytotoxic drugs. Membrane transporter hyperactivity is a major contributor to MDR and is the primary target of both diagnostic and therapeutic interventions. Multi-xenobiotic resistance can be exploited as several fluorescent indicator probes are extruded by the same drug transporters, making it possible to quantitatively measure MDR activity in cell lines and clinical samples by flow cytometry. The literature on MDR is reported in a number of different formats, making it difficult to compare data from various groups. This article will briefly review the pathomechanism, then focus upon the diagnostic approach, the interpretation of results from clinical samples and correlations with other variables. The authors believe that a standardized MDR assay, as well as a suitable monitoring test, may become a prognostic marker in several types of leukemia.