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.

Diagnostic accuracy and prognostic value of the CD64 index in very low birth weight neonates as a marker of early-onset sepsis.

OBJECTIVE: To assess the diagnostic and prognostic utility of CD64 expression as a marker of early-onset sepsis (EOS) in very low birth weight (VLBW) neonates. METHODS: Neutrophil CD64 expression (CD64 index) was assessed in 129 VLBW neonates within 72 h after birth. The accuracy of the CD64 index in predicting EOS was determined by receiver operating characteristic curve analysis. The relationship between the expression of the CD64 index and neonatal outcomes was evaluated by multivariate analysis. RESULTS: The highest performance of the CD64 index was achieved at 24 h after birth; accuracy, sensitivity, and negative predictive values were 0.85, 0.89, and 0.99, respectively, with a cut-off value of 2.4. The increased expression of CD64 index was significantly associated with subsequent infections (relative risk 1.54; 95% confidence interval 1.02-2.33). CONCLUSIONS: The CD64 index could be used as a reliable marker of EOS in VLBW neonates and it is an independent risk factor for late-onset infections.

Congenital Plasmodium vivax malaria mimicking neonatal sepsis: a case report.

Although malaria in pregnancy can cause very significant neonatal morbidity, congenital malaria is a very rare condition in both endemic and non-endemic areas. A case of congenital malaria by Plasmodium vivax, initially mistaken for neonatal sepsis, is described. The correct diagnosis was accidentally done, as congenital malaria had been missed in the initial differential diagnosis.Vivax malaria is the leading species in congenital infections in Europe. This condition should be included in the differential diagnosis of neonatal sepsis even if the mother has no proven malarial episodes during the gestational period.