Features, reason for testing, and changes with time of 583 paroxysmal nocturnal hemoglobinuria clones from 529 patients: a multicenter Italian study.

In this study, we aimed at disclosing the main features of paroxysmal nocturnal hemoglobinuria (PNH) clones, their association with presentation syndromes, and their changes during follow-up. A large-scale, cooperative collection (583 clones from 529 patients) of flow cytometric and clinical data was entered into a national repository. Reason for testing guidelines were provided to the 41 participating laboratories, which followed the 2010 technical recommendations for PNH testing by Borowitz. Subsequently, the 30 second-level laboratories adopted the 2012 guidelines for high-resolution PNH testing, both upon order by the local clinicians and as an independent laboratory initiative in selected cases. Type3 and Type2 PNH clones (total and partial absence of glycosyl-phosphatidyl-inositol-anchor, respectively) were simultaneously present in 54 patients. In these patients, Type3 component was sevenfold larger than Type2 (p < 0.001). Frequency distribution analysis of solitary Type3 clone size (N = 442) evidenced two discrete patterns: small (20% of peripheral neutrophils) and large (> 70%) clones. The first pattern was significantly associated with bone marrow failure and myelodysplastic syndromes, the second one with hemolysis, hemoglobinuria, and thrombosis. Pediatric patients (N = 34) showed significant preponderance of small clones and bone marrow failure. The majority of PNH clones involved neutrophils, monocytes, and erythrocytes. Nevertheless, we found clones made exclusively by white cells (N = 13) or erythrocytes (N = 3). Rare cases showed clonal white cells restricted only to monocytes (6 cases) or neutrophils (3 cases). Retesting over 1-year follow-up in 151 cases showed a marked clone size increase in 4 cases and a decrease in 13, demonstrating that early breaking-down of PNH clones is not a rare event (8.6% of cases). This collaborative nationwide study demonstrates a clear-cut difference in size between Type2 and Type3 clones, emphasizes the existence of just two classes of PNH presentations based on Type3 clone size, depicts an asymmetric cellular composition of PNH clones, and documents the possible occurrence of changes in clone size during the follow-up.

The diagnostic use of ADVIA 2120i Siemens and an "APL criteria" can help to reduce the rate of early death in the APL.

INTRODUCTION: Acute promyelocytic leukemia (APL) is a type of acute myeloid leukemia (AML) with a life-threatening coagulopathy. Once it is suspected, ATRA should be started. Appreciation of APL details is critical, but an experienced hematopathologist may not be available. We developed an algorithm, based on the parameters generated by automated blood cell counter ADVIA 2120i Siemens that can aid the diagnosis of APL. METHODS: All parameters in the algorithm were selected on the bases of the pathophysiology of the APL and the analyzer's technology. We used c1 cutoff: PLT < 150 × 103 ; % Mono<10; % LUC<4; % hyperchromic cells > 2; %saturated cells ≥ 1; % blasts > 4. Satisfying at least five of six cutoffs, we obtained an "APL criteria". It was tested on 247.209 raw-data from routine and emergency samples and on 124 raw-data from APL. We performed a multiparametric analyses and obtained definitive cutoffs (c2). It was validated on a new group of 51.002 raw-data from routine and emergency. Finally, it was tested on AML and ALL, MDS, MPN, oncologic samples, and hemolytic and megaloblastic anemia. RESULTS: The algorithm provided a high sensitivity (86.30%) and high specificity (99.83%) in APL with high or normal number of WBC and satisfactory results in APL with cytopenia (80%). The specificity was very high also in groups of hematological and nonhematological diseases. It can be used as an "APL criteria" to alert pathologists of the possible presence of APL. It together with instrumental and classical morphology may allow to reduce the time of diagnosis with further reduction in early death.

Possibility of myelodysplastic syndromes screening using a complete blood automated cell count.

Diagnosis of MDS has changed during the last years because of the 2008 WHO classification. Complete blood cell count (CBC) is a very important tool both for diagnosis of MDS. The aim of this study was to evaluate if it is possible to use the abnormal signals produced by dysplastic cells to produce a flag "dysplasia" able to identify the patients needing further hematological investigations. The proposed flag has been tested in a large group of patients to evaluate the sensibility and specificity. We create 5 patterns of MDS. Our study demonstrated that the flag "dysplasia" is specific and sensible for MDS.