Monoclonal antibody panels for acute leukemia and myelodysplastic syndrome diagnosis. Results of a co-operative quality control group.

The need for standardization criteria and result reproducibility in immunophenotyping hematological diseases has increased along with their clinical importance. Our group "Policentric Study Group on Immunological Markers", is composed of 40 laboratories. Its aim, over recent years, has been to find a standardized way of immunophenotypic analysis applicable to various hematological diseases. The objective of this study is to contribute to the debate concerning standardization of monoclonal antibody panels and immunophenotypic analysis procedures in acute leukemia (AL) and myelodysplastic syndrome (MDS), with the following targets: to improve interlaboratory reproducibility of the immunophenotyping data, and interpretative results; to study, with improved feasibility, correlation between immunophenotype and clinical or biological findings on a large number of AL and MDS cases; to verify the utility of the proposed monoclonal antibody panels for proper AL and MDS classification, and to detect minimal residual disease. In the field of AL and MDS our experience is based on about 1800 and 700 cases respectively analyzed over the last five years. Starting from these experiences and data of the literature we have elaborated the proposed panels of monoclonal antibodies and the methods of analysis. We have suggested a standardized immunophenotypic approach to study AL and MDS. In particular our work has focused on the gating strategy. This aims at drawing a gate of analysis having high purity and recovery, and on the choice of monoclonal antibody combinations for multiparametric analysis, particularly the normal antigen expression on each step of lineage differentiation or their clinically relevant aberrant expressions. A standardized criteria has become a necessary starting point in any kind of analytical process. In the field of acute leukemias and myelodysplastic syndromes the work of this polycentric group has focused on the pre-analytical and analytical steps to be taken in cytometric evaluation of hematological malignancies. The results obtained may contribute to reaching intra and inter-laboratory reproducibility.

An Italian national multicenter study for the definition of reference ranges for normal values of peripheral blood lymphocyte subsets in healthy adults.

BACKGROUND AND OBJECTIVE: Reference ranges are necessary in clinical chemistry and hematology to compare an observed value and to provide meaningful information. The aim of this multicenter study was the definition of reference ranges of the relative and absolute numbers of lymphocyte subsets by evaluating a large cohort of healthy adults and by using a standard protocol to reduce the variability in both sample preparation methodology and flow cytometer operation. Other aims of this study were the evaluation of the influence of sex, age, obesity, smoking, sport and some methodological variables on lymphocyte subsets and the comparison of differential white blood cell values obtained by flow cytometry and those obtained by hematology counters. DESIGN AND METHODS: Blood samples from 1311 healthy adults (blood donors and volunteers chosen according to the Italian law for donor selection) were analyzed to study, by flow cytometry, the immunophenotype of lymphocyte subsets and their distribution in terms of percentages and absolute values. Pre-analytical and analytical phases were performed according to the guidelines of the International Federation of Clinical Chemistry (IFCC) and the Italian Group of Cytometry (GIC). T cells were defined by the expression of CD3; T subpopulations by the coexpression of CD4 or CD8 or HLA-DR; B-lymphocytes were identified by the expression of CD19 while natural killer lymphocytes were identified by positivity of CD16 and/or CD56 without CD3. We calculated, for each laboratory and for all data collected, the frequency distribution percent values and absolute values of each lymphocyte subset. The influence of age, sex, smoking, obesity and sport was calculated by the t-test. The influence of some methodological variables was calculated by the t-test and multiple regression test. RESULTS: Fifty-three flow cytometry laboratories at different institutions in Italy participated in this study. Data was obtained from 1311 healthy adults aged from 18 to 70; 968 phenotype analyses (74%) were considered eligible for statistical analysis. Significant results were found as regards sex, smoking and some methodological variables (quantity of sample, washing procedures, brand of monoclonal antibodies and kind of instruments used). The comparison between hematology counters and cytometers showed no difference for any of the parameters considered. INTERPRETATION AND CONCLUSIONS: The large number of cases, the different kinds of laboratories and their distribution throughout the country make our sample representative of the Italian adult population. The standardization criteria of pre-analytical and analytical phases (the most important issues in evaluating reference values for an indicator) assured good reproducibility among laboratories so that the obtained reference ranges may be useful for interlaboratory comparison of results. Instruments and the brand of monoclonal antibodies may represent an inevitable cause of variability.

Hepatitis B vaccination in uremic patients: comparison between recombinant and plasma-derived vaccine.

The immune response to recombinant and plasma-derived vaccines was evaluated in 53 and 43 uremic patients, respectively. The total rate of seroconversion was around 80% with both vaccines, although a significantly higher response was obtained with the protocol using recombinant vaccine.

[A renal tumor in a female HIV-positive patient. A case report]. / Tumore renale in una paziente HIV positiva. Descrizione di un caso.

Patients with the acquired immunodeficiency syndrome (AIDS) are at increased risk of developing certain malignant tumours. The authors report a case of renal tumour in a HIV-positive patient.

[HBV infection in hospital health workers: study conducted in a Piedmontese hospital]. / Infezione da HBV fra gli operatori sanitari ospedalieri: indagine condotta in un ospedale piemontese.

The screening for hepatitis B virus infection markers of 976 hospital employees pointed out that: the prevalence of subjects who are positive to at least one marker is relatively low (17.52%); the areas with higher rates of prevalence are: the infections diseases division and the radiological area; there is a statistically significant difference as for the positivity of one of the hepatitis B markers among the disaggregated non-medical staff for every single functional area. The data here collected are compared with those collected in other hospitals.