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The authors reported the outcome of a retrospective study of patients with HELLP syndrome to verify whether this pathology is a clinical entity with models of evolution, regression and well defined treatment. A total of 20 individual cases were reported at the Division of Obstetrics and Gynecology at the G. Gaslini Institute during the period from January 1990 to September 1995. All cases showed the normalisation of the various clinical and hematochemical parameters within a maximum of 8 days after birth. The rapid diagnosis, the immediate extraction of the fetus and appropriate medical treatment led to the prompt resolution of this severe pathology without the need for demolitive surgery frequently used in the past.

Essential thrombocythemia (ET) is a chronic myeloproliferative disease, rarely observed in pediatric age, characterized by a persistently increased platelet count. Abnormalities of platelet function observed in ET patients may be, at least in part, responsible for the thrombohemorrhagic complications. The authors report about a pediatric patient affected by ET, showing an abnormal platelet response following stimulation by anti-platelet monoclonal antibody. Such finding may be attributable to a structural abnormality of the platelet fibrinogen receptor or to post-receptor alterations.

Glanzmann's thrombasthenia is an autosomal recessive life-long bleeding disorder, originated from a quantitative or qualitative defect of the major platelet membrane receptor: the GPIIb/IIIa complex. The GPIIb/IIIa complex is a calcium-dependent heterodimer, belonging to the integrin superfamily. The complex of activated platelets can bind fibrinogen, von Willebrand factor, fibronectin and vitronectin, which are proteins playing an important role in platelet adhesion and aggregation. Thrombasthenic platelets are deficient in GPIIb, GPIIIa and GPIIb/IIIa complex; however, platelets from few thrombasthenic patients content near-normal amounts of functionally abnormal complex. The GPIIb/IIIa quantitative or functional defect leads to defective platelet hemostatic plug formation. Hemorrhagic symptoms consist of purpura, gingival hemorrhage, menorrhagia and epistaxis. Some cases of Glanzmann's thrombasthenia have been characterized at the molecular genetic level. Molecular abnormalities include: GPIIb or GPIIIa partial gene deletion, GPIIIa gene insertion, a point mutation resulting in an amino acid substitution within the GPIIIa molecule. In spite of the contemporary reduction of both GPIIb and GPIIIa in most cases of Glanzmann's thrombasthenia, it appears that a molecular abnormality affecting only one of the glycoprotein genes may result in a thrombasthenic phenotype.

The glycoprotein (GP) IIb/IIIa complex is the most abundant platelet membrane receptor (approximately 80,000 copies/platelet). The GP IIb/IIIa complex is an adhesion receptor belonging to the integrin superfamily; it can bind five adhesive proteins containing the arginine-glycine-aspartic acid (RGD) sequence in their structure: fibrinogen (Fg), von Willebrand factor (vWf), thrombospondin (Tsp), fibronectin (Fn) and vitronectin (Vn). Fg mediates platelet aggregation; vWf, Tsp and Fn are large molecules that support platelet adhesion to vessel wall; Vn is a molecular connection among hemostasis and others physiological processes. The complex is presents at any time on the platelet surface, but macromolecular ligands cannot access to their receptor because of steric hindrances intrinsic to the complex itself or its microenvironment. Adhesive proteins can bind to the complex only after platelets become activated; following platelet stimulation and ligand binding a conformational change takes place, accompanied by expression of new epitopes termed LIBS (ligand-induced binding sites). The complex-bound fibrinogen undergoes to a progressive rearrangement which increases the adhesive function of the molecule. The RGD sequence present in adhesive proteins, in addition to its receptor role, may serve as a trigger sequence that induces a high affinity ligand-binding state in the GP IIb/IIIa complex. The different domains of adhesive proteins can bind to platelet surface receptors, other than GP IIb/IIIa, so realizing multiple ligand-receptor interactions.

To investigate the effective usefulness of penicillin prophylaxis in splenectomized patients, we retrospectively focused on a group of sixty-two splenectomized patients affected by thalassemia major. Thirty-six out of 62 has been receiving monthly 1.200.000 Us. of benzathine-penicillin as prophylaxis. The remaining 26 did not receive prophylaxis, but was treated with antibacterial drugs as soon as symptoms of upper respiratory tract infection occurred. During a total period of eleven years of observation we did not observe any pneumococcal sepsis; the incidence of bacterial infections within the two groups is not different. We conclude for the uselessness of penicillin prophylaxis in splenectomized beta-thalassemic patients.

The authors investigated the incidence of thalassemia traits and hemoglobinopathies in western Liguria, where up to 70% of people comes from other italian regions, particularly from the South. The authors screened 442 primary school pupils in Albenga and Andora (Savona). Laboratory investigations permitted to detect 19 thalassemia trait carrier subjects (4.30% of the total examined): 12 of them were diagnosed heterozygous for beta-thalassemia, 6 for alpha-thalassemia, and 1 for Hb S. Authors would underline that more than half of the screening positive subjects resulted carrier of beta-thalassemia or Hb S trait, both potentially able to give origin to severe diseases: homozygous beta-thalassemia, sickle cell anemia, and beta-thalassemia/Hb S double heterozygosity.

The laboratory tests of 38 patients in pediatric age with Disseminated Intravascular Coagulation (DIC) were retrospectively evaluated. In all patients were performed PT, aPTT, platelets count, FDP dosage and biological assay of Fibrinogen. In most of them the activity of FII, FV, FVII, FX and FVIII was assaied. According to the diagnostic criteria of FSP greater than 8 micrograms/ml, Platelets less than 150 10(9)/1 and Fibrinogen less than 150 ml/dl, in 16 patients the diagnosis of DIC was possible since first examination, while in 9 patients it became possible within 2-4 days; in 13 patients we never could diagnose DIC, although it was reasonably present, since the criteria above mentioned were never simultaneously satisfied. Looking back in our experience, we confirm that the platelets count and the quantitation of plasmatic Fibrin Degradation Products (FDP) are the most useful tests for the diagnosis of full blown DIC, and that the biological assay of plasmatic fibrinogen helps to follow the disorder. A low level of FVIII:C seems to be a forecast of failure. None of the other test performed give any useful information for diagnosis when it is not possible with the above mentioned tests.