M C Arista’s research while affiliated with Sapienza University of Rome and other places

Red blood cell (RBC) autoimmunization is a relatively uncommon cause of anemia in children and presents some differences from those of adults. Due to its frequency, autoimmune hemolytic anemia (AIHA) in childhood has prompted very few studies, and the literature consists mostly of sporadic case histories. The objective of this study was to stress the importance of an appropriate serologic diagnosis in suspected cases. This report describes the immunohematologic features of 100 patients with AIHA studied in the Immunohaematologic Unit of Blood Bank, "La Sapienza" University of Rome. The patients were diagnosed in the same department from 1983 to 2003. The peak incidence of AIHA was in the first 4 years of life. No sex predominance was noted. Warm AIHA was the most common type of acquired immune hemolytic anemia; it comprised 64 of the 100 patients, whereas 26 patients showed a cold AIHA. Associated AIHA showed a slightly more frequent incidence (54/100) compared to idiopathic forms of AIHA (46/100). In this study serologic records of 100 children with confirmed AIHA are reported. This series, much larger than any previously reported, is critically reviewed and analyzed to delineate the immunologic features of the disease in childhood.

Background. The aims of this study were to compare the sensitivity of two microcolumn methods for the identification of irregular antibodies using panels of red blood cells at a concentration of 0.8% or 3%, to evaluate the specificity of the method at 0.8%and to assess the utility of dedicated software for the identification of antibodies (Resolve Panel System and Expert Resolvigen 3). Materials and methods. The study was carried out in five centres using panels of 33 identification cells, of which 11 were treated with ficin, at the concentrations of 0.8% and 3%. For the sensitivity evaluation, each centre studied 49 samples known to contain irregular antibodies of various complexity. Each sample was tested with both panels (0.8% and 3%). For the specificity evaluation 100 samples, previously found to be negative, were tested. Results. Were interpreted both manually and with the aid of the dedicated software system. Of the 49 sera examined, 32 were identified by all the centres, while 17 were not identified by all the centres. In 63% of the cases the reactivity was greater with the 0.8% panels, in 11% with the 3% panels and in 26% of the cases the reactivity was similar. In 33 of 217 cases the results of the search for antibodies were discrepant between the two panels; in 23 of these the results expected were those obtained with the 0.8% panels. All the samples known to be negative were confirmed to be such with the 0.8% panel. Conclusion. This study also confirmed the better reactivity of the 0.8% panels than the 3% ones for the identification of antibodies, without problems of specificity which, in the samples studied, was 100%. The dedicated software was judged useful and able to save time in the procedures to identify antibodies, especially in the more complicated cases.

Paroxysmal nocturnal haemoglobinuria (PNH) is characterized by the expansion of phosphatidylinositol glycan class A (PIG-A) defective haematopoietic cells, probably due to the immune-mediated alterations of the bone marrow environment selecting PIG-A- stem cells. The present study investigated the presence of alterations of the immune system in a population of 11 PNH patients. The production of interferon-gamma (IFN-gamma) and interleukin-2 (IL-2), evaluated by intracellular cytokine analysis, and the frequencies of class I and II human leucocyte antigen (HLA) alleles were studied in comparison with healthy human subjects. Similar percentages of lymphocytes produced cytokines in PNH patients and controls after costimulation-independent activation; however, a negative correlation was found between the percentage of IFN-gamma producing cells and white cell or platelets counts. PNH patients showed an higher percentage, compared with controls, of IFN-gamma producing cells after costimulation-dependent activation. The frequency of HLA-A31 was higher in patients than in controls (27.2% vs. 4%), similarly to that of HLA-B7 (27.2% vs. 6%). With regard to class II alleles, 18% of PNH patients expressed DQB1*04 compared with none of 50 control cases. This study supports the hypothesis that immune alteration are present in PNH and that the immunogenetic background could influence the development of the disease.

Over the last few years, quality system requirements have been introduced for blood components. The necessary compliance with standard productions will have a considerable impact on Blood Banks. The introduction of automated methods is the most satisfactory means to meet these requirements for blood component preparation. A new device has been developed to automate the fractionation of blood into components. We evaluated the efficacy of this instrument as compared to manual methods. A total of 218 units of blood have been collected, into several different commercial blood bag systems (77 into standard quadruple bag systems, 141 into bag systems with integrated in line filters), and used to evaluate the universality of the instrument. Whole blood units were processed using the Top/Top system and the Compomat G4 (Fresenius HemoCare). A separate program protocol was developed for each kind of bag. Use of the Compomat G4 resulted in a statistically significant (p<0.001) increase of the hemoglobin in filtered red cell concentrates (RCC) in comparison with the manual procedure, and a similar trend, even not statistically significant, has been observed for filtered RCC. Regardless of bag systems, we were able to observe a statistically significant increase of platelets in the platelet concentrates (PCs), when comparing automatic versus manual procedure. The automated procedure has been shown to be fast, and easy for the operators. This device reliably produces acceptable blood components, and has been shown adaptable to use with different blood bag systems.

We studied the behavior of blood lymphocyte subsets in 25 adult patients with autoimmune thrombocytopenic purpura (ATP) submitted to splenectomy. An increase of absolute concentrations of T-subset lymphocytes was observed in the different groups of splenectomized patients; in no responding/relapsing subjects was an activation of T-lymphocytes demonstrated.

We studied the general outcome in 94 adult patients with autoimmune thrombocytopenic purpura (ATP) submitted to splenectomy. Of 84/94 patients who presented a complete or partial response 30 d after splenectomy, 16 (19%) showed one or more relapses. The clinical situation of the 81 patients still under observation is as follows: 13 unrensponsive, 60 completely or partially responsive, without relapses during the follow-up, 8 completely or partially responsive after one or more relapses. No correlation was found between the favourable splenectomy outcome and age at splenectomy, the diagnosis-splenectomy interval and initial response to corticosteroids. The probability of disease-free survival is 83%, projected at 10 yr, while the overall survival is 93%, projected at 10 yr. PAIgG levels of the normal subjects and of responding patients were found to be similar, while in the groups of non-responding/relapsing patients, significantly higher values of PAIgG were detected, as compared to the control group.