Chiara Ambaglio

Platelet size distinguishes between inherited macrothrombocytopenias and immune thrombocytopenia.

Summary.  Background: Distinguishing inherited thrombocytopenias from immune thrombocytopenia (ITP) can be difficult, and patients are therefore at risk of misdiagnosis and inappropriate treatments. Although it is known that the most common inherited forms of thrombocytopenia are characterized by increased platelet size, the diagnostic power of this feature has never been investigated. Objectives: The aim of this study was to test the hypothesis that platelet size can be used to differentiate ITP from inherited macrothrombocytopenias. Patients/methods: We measured mean platelet volume (MPV) and mean platelet diameter (MPD), within 2 h of blood sampling, in 35 patients with inherited macrothrombocytopenias [15 MYH9‐related disease (MYH9‐RD), three biallelic and 17 monoallelic Bernard–Soulier syndrome (BSS)], and 56 with ITP. Using receiving operating characteristic analysis, we searched for the best cut‐off values to differentiate between these conditions. Results: As expected, platelets were larger in inherited macrothrombocytopenias than in ITP. An MPD larger than 3.3 μm differentiated MYH9‐RD and BSS from ITP with 0.89 sensitivity and 0.88 specificity, and an MPV larger than 12.4 fL had 0.83 sensitivity and 0.89 specificity. Combining MPD with MPV increased sensitivity and specificity to 0.97 and 0.89, respectively. Conclusion: Platelet size evaluation by both an appropriate cell counter and blood film examination is useful for differentiating inherited macrothrombocytopenias from ITP.

Congenital amegakaryocytic thrombocytopenia: clinical and biological consequences of five novel mutations

Background and Objectives Congenital amegakaryocytic thrombocytopenia (CAMT) is a rare, autosomal recessive disorder induced by mutations of the gene coding for thrombopoietin (TPO) receptor (c-MPL). Patients initially present with isolated thrombocytopenia that subsequently progresses into pancytopenia. Although the mechanisms leading to aplasia are unknown, the age of onset has been reported to depend on the severity of the c-MPL functional defect. To improve our knowledge in this field, we studied clinical and biological features of five new patients. Design and Methods We diagnosed five CAMT patients, identified c-MPL mutations, including five novel alterations and investigated relationships between mutations and their clinical-biological consequences. Results In all cases, platelet c-MPL and bone marrow colonies were reduced, while serum TPO levels were elevated. We also documented that the percentage of bone marrow cells expressing tumor necrosis factor-α and interferon-γ was increased during pancytopenia as compared to controls, suggesting that, as in other bone marrow failure diseases, these inhibitory cytokines contributed to the pancytopenia. Contrary to previously published data, we found no evidence of correlations between different types of mutations and the clinical course. Interpretation and Conclusions These results suggest that therapies, such as hematopoietic stem cell transplantation, which are potentially curative although associated with a risk of treatment-related mortality, should not be postponed even in those CAMT patients whose c-MPL mutations might predict residual activity of the TPO receptor.

Thrombopoietin is not uniquely responsible for thrombocytosis in inflammatory disorders.

A few studies in patients with reactive thrombocytosis identified levels of the hormone higher than expected, and suggested that TPO behaves as an acute-phase protein and was responsible for increased platelet count. At the opposite, other studies did not find any significant rise of the hormone in patients who similarly developed reactive thrombocytosis. To gain further information on this topic, we compared TPO levels and platelet counts in two series of patients hospitalized for acute illnesses: one with strong elevation of both erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), and the other with normal values. Within the group of subjects with high ESR and CRP, 38 had normal platelet counts, while 15 had thrombocytosis. No thrombocytosis was observed in control patients. Patients with high acute phase indexes had significantly higher TPO levels and platelet counts than control patients. We identified significant positive correlations between ESR and CRP, and between TPO and CRP. Interestingly, no significant relationship between platelet counts and TPO levels was find. When we grouped patients with acute-phase reaction according to absence or presence of thrombocytosis, we found similar TPO values. Conversely, positive correlations between platelet count and IL-6 and between TPO and IL-6 have been identified. All together our results confirm that TPO acts as an acute phase protein but exclude the possibility that it is uniquely responsible for thrombocytosis of inflammatory disorders, which might recognize in IL-6 a credible candidate as a cooperating factor.

Activated prothrombin complex concentrate (FEIBA®) for the treatment and prevention of bleeding in patients with acquired haemophilia: A sequential study

Despite anti-haemorrhagic therapy with proper doses of activated prothrombin complex concentrate (aPCC, Feiba®), patients with acquired haemophilia A (AHA) have a considerable risk of recurrent bleeding complications. Evidence in support of the benefit-to-risk ratio of prevention strategies with the use of lower doses of aPCC following the end of the initial treatment period is scarce and inconclusive. We report our experience in the management of 18 consecutive patients with AHA admitted to two Haemophilia centres in Italy. We managed the first 11 according to current guidelines (e.g., with conventional aPCC doses until bleeding resolution). Then, we decided to prolong the treatment beyond bleeding resolution with lower doses of the same concentrate (short-term prophylaxis) in the 7 additional patients. In these patients, the treatment was continued for as long as the titre of FVIII inhibitor was found to decrease by at least 50% when compared to the baseline one. We observed six relapses of bleeding in patients in whom aPCC was confined to the treatment of the qualifying bleeding episode, and none in patients to whom lower doses were administered until the pre-specified decrease in the titre of FVIII inhibitor was achieved. No patients experienced thrombotic complications during the study period. Prolonging the treatment with lower doses of aPCC beyond the initial phase in patients with AHA in whom the titre of FVIII inhibitor is still high is likely to safely prevent further bleeding complications.

Plasma exchange and immunosuppressive therapy in a case of mild haemophilia A with inhibitors and a life-threatening lower limb haemorrhage.

The development of inhibitors in severe haemophilia A is a well-known serious complication of exposure to factor VIII (FVIII) concentrates. It occurs in up to 30% of patients and makes bleeding episodes refractory to standard treatment. In mild haemophilia A treatment with FVIII concentrates is indicated after trauma and for surgery; this treatment, too, may be complicated by the occurrence of inhibitors, with the frequency of this complication being reported to be between 3% and 13%1–3. In such patients it represents a major challenge and changes the phenotype from mild to severe, so that the patients are at risk of spontaneous bleeding. Unlike in severe haemophilia A, only few risk factors have been recognised, such a positive family history of inhibitors, age at first exposure, age at peak treatment, some missense mutations in the factor VIII gene and intensive FVIII replacement treatment, often in the setting of surgery and continuous infusion delivery3–6. According to the main guidelines7–9, bleeding episodes in patients with haemophilia and inhibitors should be treated with bypassing agents prior to immune tolerance induction (ITI). The success of ITI is higher when its initiation is delayed until the inhibitor titre has fallen below 10 BU/mL. For patients with mild haemophilia A and inhibitors, a trial of bypassing therapy on demand should precede consideration of ITI. The choice of therapy depends on the inhibitor titre: large doses of FVIII can be sufficient to control major haemorrhage if the antibody titre is less than 5 BU/mL, while if it is higher FVIII overtreatment is unlikely to be effective without the removal of antibodies. In this case, recombinant activated factor VII (rFVIIa) or activated prothrombin complex concentrates (FEIBA) are recommended in the acute phase of bleeding; when one of these fails, the other product may be used. If both the bypassing agents cannot ensure control of bleeding, an alternative approach could be the use of concomitant antibody removal and high-dose FVIII, as historically proposed three decades ago by Nillson and colleagues10–11 and still considered effective12–14. A similar approach has also been used in the setting of acquired haemophilia A15,16. High-titre antibodies can be removed temporarily by extracorporeal adsorption of the antibody to protein A-sepharose or to polyclonal sheep antibodies in columns17–19. Therapeutic plasma exchange (TPE) still has a role in the treatment of coagulation factor inhibitors, as reported in international guidelines 13. ITI has been used in few patients with mild haemophilia A and the success rate in such patients seems lower than that in patients with severe haemophilia A3,14. The success of this approach is defined as the elimination of the inhibitors, the normalization of the half-life of infused FVIII and the absence of an anamnestic response. The eradication of inhibitors may be achieved with immune modulation using drugs such as steroids and cyclophosphamide10,11. We present the case of a patient with mild haemophilia A with high titre inhibitors and life-threatening bleeding unresponsive to bypassing agents. The critical situation required the use of both removal of the antibodies by TPE, overtreatment with plasma-derived FVIII concentrates and stabilisation of the clinical response with immunosuppressive therapy and early start of ITI.

Sex-specific differences in the distal versus proximal presenting location of acute deep vein thrombosis

BACKGROUND AND AIMS Women present with pulmonary embolism (PE) more often than men, while the opposite is true for proximal deep vein thrombosis (DVT). We investigated whether sex-specific differences exist in the presenting location of acute symptomatic DVT among patients without concomitant PE. METHODS We tested our hypothesis in a meta-analysis of studies selected by systematically reviewing PubMed, Embase, and the grey literature. Thereafter, we analysed data of a single-center cohort including patients with first isolated acute DVT to assess the additional impact of age and provoking risk factors on the presenting location of DVT. RESULTS We identified 7 studies for a total of 20,534 patients. The weighed pooled absolute difference in the proportion of distal DVT between women and men was +5.4% (95%CI: +0.7%; +9.5%), which corresponds to a pooled odds ratio (OR) of 1.30 (95%CI: 1.07-1.58). This difference was +6.5% (95%CI: +2.1%; +10.9%) for first distal DVT (OR 1.38; 95%CI: 1.11-1.72) and +5.3% (95%CI: +0.5%; +10.0%) for either first or recurrent distal DVT (OR 1.29; 95%CI: 1.03-1.61). In the cohort study, the larger difference in the proportion of distal DVT between women and men was observed among patients aged 51-70 (+9.5%; 95CI: +2.8%; +16.0% compared to those aged 18-50) or with unprovoked events (+8.5%; 95CI: -0.9%; +17.9%). CONCLUSIONS Among patients with first symptomatic isolated acute DVT, women presented with distal DVT more often than men, whereas men had a higher proportion of proximal DVT events. This pattern appeared to depend on age and the absence of provoking risk factors for VTE.

Activated prothrombin complex concentrate (FEIBA®) in acquired haemophilia A: a large multicentre Italian study - the FAIR Registry

14 August 2017) Fabre, J.-E., Nguyen, M., Athirakul, K., Coggins, K., McNeish, J.D., Austin, S., Parise, L.K., FitzGerald, G.A., Coffman, T.M. & Koller, B.H. (2001) Activation of the murine EP3 receptor for PGE(2) inhibits cAMP production and promotes platelet aggregation. Journal of Clinical Investigation, 107, 603–610. Gross, S., Tilly, P., Hentsch, D., Vonesch, J.-L. & Fabre, J.-E. (2007) Vascular wall–produced prostaglandin E2 exacerbates arterial thrombosis and atherothrombosis through platelet EP3 receptors. Journal of Experimental Medicine, 204, 311–320. Ikeda-Matsuo, Y., Tanji, H., Narumiya, S. & Sasaki, Y. (2011) Inhibition of prostaglandin E2 EP3 receptors improves stroke injury via antiinflammatory and anti-apoptotic mechanisms. Journal of Neuroimmunology, 238, 34–43. Iyu, D., Glenn, J.R., White, A.E., Johnson, A.J., Fox, S.C. & Heptinstall, S. (2010) The role of prostanoid receptors in mediating the effects of PGE2 on human platelet function. Platelets, 21, 329–342. Saleem, S., Kim, Y.T., Maruyama, T., Narumiya, S. & Dor e, S. (2009) Reduced acute brain injury in PGE(2) EP3 receptor–deficient mice after cerebral ischemia. Journal of Neuroimmunology, 208, 87–93. Tilly, P., Charles, A.-L., Ludwig, S., Slimani, F., Gross, S., Meilhac, O., Geny, B., Stefansson, K., Gurney, M.E. & Fabre, J.-E. (2014) Blocking the EP3 receptor for PGE2 with DG-041 decreases thrombosis without impairing haemostatic competence. Cardiovascular Research, 101, 482–491.

A case of feverish neutropenia

A case of feverish benign neutropenia occurring in a diabetic patient receiving pregabalin for peripheral neuropathy is reported. Although pregabalin‐induced neutropenia is very rare, it is important to keep in mind that this drug like other anticonvulsants used for neuropathic pain, can cause severe neutropenia.

Protocollo per l’identificazione di pazienti con difetti congeniti dell’emostasi non noti: screening pre-operatorio

Congenital Hemorrhagic Diseases (CHD) are often complicated by intra- and post-surgical bleeding that is the cause of diagnostic procedures. This study presents a protocol applied to the patients with indication of elective surgery, aimed to detected CHD and the consequent surgical hemorrhagic risk, on the basis of structured history concerning bleeding tendency (Bleeding Score-BS) and/or laboratory clotting screening tests. 1100 consecutive patients have been enrolled. The abnormal BS and/or alterations of screening clotting tests, have been further evaluate by medical staff experienced on hemostasis to make the diagnosis of CHD and to suggest hemostatic prophylaxis during and after surgery. In conclusion these preliminary data do not support the hypothesis that mild CHD are under diagnosed in general populations. A case-control study will be planned to register eventual differences on bleeding surgical complications between patients considered as care or as control in our protocol.

Prevalenza di trombosi arteriose e venose in presenza delle mutazioni G20210A del gene della protrombina e R506Q del gene del fattore V (Leiden)

Arterial and venous thrombosis is becoming a pathology of primary importance because of other concomitant pathologies (metabolic, cardiac, neoplastic diseases) which often acerbate the prognosis. Therefore, our research aims to clarify in particular the function of congenital prothrombotic risk factors, that is the R506Q gene muta-tion of the FV (Leiden) and the G20210A gene mutation of the FII. We analyzed 351 subjects in treatment at the Hemostasis Diseases Unit of IRCCS Policlinico San Matteo Foundation, Pavia. We collected each personal and family anamnesis and carried out the thrombophilia screening test. Among this population, 63 subjects resulted positive to, at least, one of the two mutations we studied. Comparing the number of subjects having at least a mutation with the ones without mutations, we found out that the first ones had a higher VTE percentage than the second ones. We also examined risk factors. All the results were supporting the thrombosis disease. Processing people to the thrombophilia screening test means to recognise and manage subjects at risk before the thrombosis event happens.