Assessment of post-partum haemorrhage risk among women with moderate thrombocytopenia.

It is unknown whether moderate thrombocytopenia represents a risk factor for post-partum haemorrhage (PPH). We assessed PPH risk among women with a platelet count of between 100 and 50 × 109 /l and stratified the risk for O/non-O blood group. We included consecutive women undergoing vaginal delivery or caesarean section with moderate thrombocytopenia. Women with >150 × 109 /l platelets at delivery were selected as controls and matched for age, type of birth and ethnicity. Odds ratios (ORs) with their 95% confidence intervals (95% CIs) were calculated as risk estimates. A total of 94 thrombocytopenic women and 94 controls were included in the study. The rate of PPH was significantly higher in thrombocytopenic women than in controls (37% vs. 10%, p < 0.001); there was a higher risk of PPH in the thrombocytopenic group when compared to the control group (adjusted OR 4.7, 95% CI 2.1-10.8, p < 0.01) and this association was stronger in blood group O carriers (adjusted OR 11.0, 95% CI 2.4-49.6, p < 0.01). In conclusion, our study shows that a moderate thrombocytopenia is a risk factor for PPH, especially in blood group O carriers.

Consumption of complement in a 26-year-old woman with severe thrombotic thrombocytopenia after ChAdOx1 nCov-19 vaccination.

Extremely rare reactions characterized by thrombosis and thrombocytopenia have been described in subjects that received ChAdOx1 nCoV-19 vaccination 5-16 days earlier. Although patients with vaccine-induced thrombotic thrombocytopenia (VITT) have high levels of antibodies to platelet factor 4 (PF4)-polyanion complexes, the exact mechanism of the development of thrombosis is still unknown. Here we reported serum studies as well as proteomics and genomics analyses demonstrating a massive complement activation potentially linked to the presence of anti-PF4 antibodies in a patient with severe VITT. At admission, complement activity of the classical and lectin pathways were absent (0% for both) with normal levels of the alternative pathway (73%) in association with elevated levels of the complement activation marker sC5b-9 (630 ng/mL [n.v. 139-462 ng/mL]) and anti-PF4 IgG (1.918 OD [n.v. 0.136-0.300 OD]). The immunoblotting analysis of C2 showed the complete disappearance of its normal band at 110 kDa. Intravenous immunoglobulin treatment allowed to recover complement activity of the classical pathway (91%) and lectin pathway (115%), to reduce levels of sC5b-9 (135 ng/mL) and anti-PF4 IgG (0.681 OD) and to normalize the C2 pattern at immunoblotting. Proteomics and genomics analyses in addition to serum studies showed that the absence of complement activity during VITT was not linked to alterations of the C2 gene but rather to a strong complement activation leading to C2 consumption. Our data in a single patient suggest monitoring complement parameters in other VITT patients considering also the possibility to target complement activation with specific drugs.

Plasma levels of extracellular vesicles and the risk of post-operative pulmonary embolism in patients with primary brain tumors: a prospective study.

Primary brain tumors are associated with an increased risk of pulmonary embolism (PE), particularly in the early post-operative period. The pathophysiological mechanisms of PE are poorly understood. This study aims to describe prospectively extracellular vesicles (EVs) levels and investigate whether or not their variations allow to identify patients at increased risk of post-operative PE. Consecutive meningioma or glioma patients candidate to tumor resection were included in the study if a pulmonary perfusion scan (Q-scan) performed before surgery ruled out PE. EVs derived from platelets (CD41+) or endothelial cells (CD144+), tissue factor-bearing EVs (CD142+) and their procoagulant subtype (annexin V+) were analyzed by flow cytometry before surgery (T0), within 24 h (T1), two (T2) and seven days (T7) after surgery. Q-scan was repeated at T2. Ninety-three patients with meningioma, 59 with glioma and 76 healthy controls were included in the study. CD142+ and annexin V+/CD142+ EVs were increased at T0 in meningioma and glioma patients compared to healthy controls. Twenty-nine meningioma (32%) and 16 glioma patients (27%) developed PE at T2. EVs levels were similar in meningioma patients with or without PE, whereas annexin V+ and annexin V+/CD142+ EVs were significantly higher at T1 and T2 in glioma patients with PE than in those without. Procoagulant EVs, particularly annexin V+/CD142+, increase after surgery and are more prevalent in glioma patients who developed PE after surgery than in those who did not.

Long-term neuropsychological sequelae, emotional wellbeing and quality of life in patients with acquired thrombotic thrombocytopenic purpura.

Neurological symptoms related to microthrombosis are the hallmark of acute manifestations of acquired thrombotic thrombocytopenic purpura (TTP). Despite the achievement of hematological remission, patients may report persisting neurological impairment that affects their quality of life. To assess the long-term neuropsychological consequences of acute TTP, we recruited 35 acquired TTP patients (77% females, median age at onset 41 years, interquartile range: 35-48) regularly followed at our out-patient clinic of thrombotic microangiopathies in Milan (Italy) from December 2015 to October 2016. Patients underwent a psychological evaluation of memory and attentional functions, emotional wellbeing and health-related quality of life at least three months after their last acute TTP event (median 36 months, interquartile range: 17-54). During the psychological consultation, 17 patients (49%) referred persisting subjective neurological impairment in the frame of a remission phase, with at least one symptom as disorientation, loss of concentration, dizziness, lack of balance, headache and diplopia. Neuropsychological assessment revealed lower scores than the Italian general population pertaining to direct, indirect and deferred memory. A higher degree of impairment of memory domains was found in patients with neurological involvement at the time of presentation of the first acute TTP episode. Anxiety and depression were detected in seven (20%) and 15 (43%) patients, respectively. Health-related quality of life was lower than the Italian general population, with mental domains more impacted than physical domains (mean difference 58.43, 95% confidence interval: 71.49-45.37). Our study demonstrates compromised memory and attention functions, persisting anxiety/depression symptoms and a generally reduced quality of life in patients recovering from acute acquired TTP. New clinical strategies should be considered to improve these symptoms.

Novel variant in HPS3 gene in a patient with Hermansky Pudlak syndrome (HPS) type 3.

Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder caused by defects in 10 human HPS genes, characterized by oculocutaneous albinism (OCA) and bleeding diathesis associated to platelet δ-storage pool defect (SPD). We report a case of 4-year-old boy from non-consanguineous parents with OCA and negative personal and familiar hemorrhagic history, referred to us for severe bleeding after mild trauma. His platelet function, studied by lumi-aggregometry, showed normal first wave of aggregation in response to exogenous agonists and impaired second wave with defective ATP release. This, in combination with impaired platelet δ-granules content (serotonin, ATP, ADP) and the OCA phenotype suggested the HPS diagnosis. HPS3: sequencing revealed a novel pathogenic homozygous variant (NM_032383.4:c.7>T, p.Gln3*) resulting in a premature stop codon at the amino acid 3. Moreover, our report highlights the importance of evaluating platelet function in children with OCA without bleeding diathesis to identify HPS early and prevent bleeding complications.

Caplacizumab for Acquired Thrombotic Thrombocytopenic Purpura.

BACKGROUND: Acquired thrombotic thrombocytopenic purpura (TTP) is caused by aggregation of platelets on ultralarge von Willebrand factor multimers. This microvascular thrombosis causes multiorgan ischemia with potentially life-threatening complications. Daily plasma exchange and immunosuppressive therapies induce remission, but mortality and morbidity due to microthrombosis remain high. METHODS: Caplacizumab, an anti-von Willebrand factor humanized single-variable-domain immunoglobulin (Nanobody), inhibits the interaction between ultralarge von Willebrand factor multimers and platelets. In this phase 2, controlled study, we randomly assigned patients with acquired TTP to subcutaneous caplacizumab (10 mg daily) or placebo during plasma exchange and for 30 days afterward. The primary end point was the time to a response, defined as confirmed normalization of the platelet count. Major secondary end points included exacerbations and relapses. RESULTS: Seventy-five patients underwent randomization (36 were assigned to receive caplacizumab, and 39 to receive placebo). The time to a response was significantly reduced with caplacizumab as compared with placebo (39% reduction in median time, P=0.005). Three patients in the caplacizumab group had an exacerbation, as compared with 11 patients in the placebo group. Eight patients in the caplacizumab group had a relapse in the first month after stopping the study drug, of whom 7 had ADAMTS13 activity that remained below 10%, suggesting unresolved autoimmune activity. Bleeding-related adverse events, most of which were mild to moderate in severity, were more common with caplacizumab than with placebo (54% of patients vs. 38%). The frequencies of other adverse events were similar in the two groups. Two patients in the placebo group died, as compared with none in the caplacizumab group. CONCLUSIONS: Caplacizumab induced a faster resolution of the acute TTP episode than did placebo. The platelet-protective effect of caplacizumab was maintained during the treatment period. Caplacizumab was associated with an increased tendency toward bleeding, as compared with placebo. (Funded by Ablynx; ClinicalTrials.gov number, NCT01151423.).

Complications of whole-exome sequencing for causal gene discovery in primary platelet secretion defects.

Primary platelet secretion defects constitute a heterogeneous group of functional defects characterized by reduced platelet granule secretion upon stimulation by different agonists. The clinical and laboratory heterogeneity of primary platelet secretion defects warrants a tailored approach. We performed a pilot study in order to develop DNA sequence analysis pipelines for gene discovery and to create a list of candidate causal genes for platelet secretion defects. Whole-exome sequencing analysis of 14 unrelated Italian patients with primary secretion defects and 16 controls was performed on Illumina HiSeq. Variant prioritization was carried out using two filtering approaches: identification of rare, potentially damaging variants in platelet candidate genes or by selecting singletons. To corroborate the results, exome sequencing was applied in a family in which platelet secretion defects and a bleeding diathesis were present. Platelet candidate gene analysis revealed gene defects in 10/14 patients, which included ADRA2A, ARHGAP1, DIAPH1, EXOC1, FCGR2A, ITPR1, LTBP1, PTPN7, PTPN12, PRKACG, PRKCD, RAP1GAP, STXBP5L, and VWF The analysis of singletons identified additional gene defects in PLG and PHACTR2 in two other patients. The family analysis confirmed a missense variant p.D1144N in the STXBP5L gene and p.P83H in the KCNMB3 gene as potentially causal. In summary, exome sequencing revealed potential causal variants in 12 of 14 patients with primary platelet secretion defects, highlighting the limitations of the genomic approaches for causal gene identification in this heterogeneous clinical and laboratory phenotype.

Acquired platelet dysfunction and overproduction of platelet cyclic AMP in two patients with myeloid malignancies.

The pathophysiology of impaired platelet function in acquired disorders is often poorly understood. We report two unrelated patients with hematologic malignancies associated with acquired severe bleeding diathesis, and complex platelet function abnormalities, including overproduction of the physiological inhibitor cyclic-AMP (cAMP). Patient 1, with mild macrocytic anemia and thrombocytopenia (100 x 109/L), was diagnosed with chronic myelomonocytic leukemia a few months after the onset of her bleeding diathesis and our analysis of platelet function. Patient 2, with bleeding diathesis of recent onset, was studied when his myelodysplastic syndrome with excess blasts had already progressed to acute myeloid leukemia. In both patients, platelet aggregation/ATP secretion, serum thromboxane B2, intraplatelet content of ADP, ATP, serotonin, and fibrinogen were severely impaired. Baseline platelet cAMP levels were mildly elevated and markedly increased after stimulation by prostaglandin E1. In conclusion, these are the first patients with myeloid malignancies associated with acquired severe platelet dysfunction and overproduction of cAMP.

Risk of post-operative venous thromboembolism in patients with meningioma.

The surgical resection of meningiomas can be complicated by venous thromboembolism (VTE) in the post-operative period, but the exact incidence of this event is not known. Aim of this study was to assess the occurrence of VTE in patients operated for meningioma who underwent a post-operative clinical and objective screening for VTE. Patients undergoing meningioma resection between 2000 and 2010 who accepted to be investigated for VTE in the post-operative period were included in the study. The screening included daily clinical assessment, pulmonary perfusion scintigraphy (Q-SCAN) on day 2 and venous compression ultrasonography (CUS) of the lower limbs within day 7. The univariate and multivariate statistical analysis of risk factors for VTE included sex, age, presence of comorbidities, pre- and post-operative Karnofsky Performance scale (KPS), post-operative neurological worsening and post-operative walking ability. Two-hundred and seventy-five patients were included in the study. VTE was diagnosed in 82 patients (29.8%). Univariate analysis revealed that age ≥ 65 years, cardiovascular comorbidities, pre- and post-operative KPS < 80/100, post-operative neurological worsening and impaired post-operative walking ability were significantly associated with VTE. Multivariate analysis confirmed only age ≥ 65 years (p = 0.011) and post-operative KPS < 80/100 (p = 0.002) as independent risk factors for VTE. Patients operated for meningioma have a 30% risk of VTE. Age ≥ 65 years and post-operative KPS < 80 were independent risk factors for VTE.

Alternate use of thrombopoietin receptor agonists in adult primary immune thrombocytopenia patients: A retrospective collaborative survey from Italian hematology centers.

Sequential use of the TPO-RAs romiplostim and eltrombopag in ITP patients failing either agent was retrospectively evaluated to assess efficacy and impact of clinical characteristics on outcome. Patients were grouped into 5 categories: efficacy issues: 1st TPO-RA failure; loss of response; non-efficacy issues: platelet fluctuations; patient's preference; adverse event development. Either one TPO-RA sequence was analyzed at 3 month and at last follow-up. 106/546 patients on TPO-RA underwent switch and 65% achieved, regained or maintained a short- term response independent of switch sequence, gender or age; lower response rates were associated with lines of previous therapy; disease duration lowers probability to respond. Clinically, patients switched for efficacy issue did not differ from those switched for non-efficacy issues. Response was achieved/regained in 57.8% of patients switched for efficacy issues, the lowest response rates were observed in non-responders to 1st TPO-RA; 80% of patients switched for non-efficacy issues maintained a response. Platelet fluctuation resolved in 44.4%. Of the 49 patients evaluable for long-term outcome, 27 were in response on therapy; 16 discontinued the TPO-RA for reasons other than efficacy, while only 6 were non responders. We confirm the efficacy of TPO-RA switch; once achieved, response to the 2nd TPO-RA seems durable.

Impact on Prehospital Delay of a Stroke Preparedness Campaign: A SW-RCT (Stepped-Wedge Cluster Randomized Controlled Trial).

BACKGROUND AND PURPOSE: Public campaigns to increase stroke preparedness have been tested in different contexts, showing contradictory results. We evaluated the effectiveness of a stroke campaign, designed specifically for the Italian population in reducing prehospital delay. METHODS: According to an SW-RCT (Stepped-Wedge Cluster Randomized Controlled Trial) design, the campaign was launched in 4 provinces in the northern part of the region Emilia Romagna at 3-month intervals in randomized sequence. The units of analysis were the patients admitted to hospital, with stroke and transient ischemic attack, over a time period of 15 months, beginning 3 months before the intervention was launched in the first province to allow for baseline data collection. The proportion of early arrivals (within 2 hours of symptom onset) was the primary outcome. Thrombolysis rate and some behavioral end points were the secondary outcomes. Data were analyzed using a fixed-effect model, adjusting for cluster and time trends. RESULTS: We enrolled 1622 patients, 912 exposed and 710 nonexposed to the campaign. The proportion of early access was nonsignificantly lower in exposed patients (354 [38.8%] versus 315 [44.4%]; adjusted odds ratio, 0.81; 95% confidence interval, 0.60-1.08; P=0.15). As for secondary end points, an increase was found for stroke recognition, which approximated but did not reach statistical significance (P=0.07). CONCLUSIONS: Our campaign was not effective in reducing prehospital delay. Even if some limitations of the intervention, mainly in terms of duration, are taken into account, our study demonstrates that new communication strategies should be tested before large-scale implementation. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01881152.

Oral Surgery in Patients With Glanzmann Thrombasthenia: A Case Series.

Glanzmann thrombasthenia is a severe defect of platelet function caused by an inherited deficiency or dysfunction of the glycoprotein IIb/IIIa complex, the platelet fibrinogen receptor. Patients with Glanzmann thrombasthenia experience lifelong spontaneous and post-traumatic mucocutaneous bleeding diathesis. Surgery is usually very challenging, requiring close cooperation among surgeons, hematologists, and anesthesiologists. For anatomic reasons, oral surgery is particularly difficult owing to the inherent risk of hemorrhage and the difficulty in achieving local hemostasis. In the present report, we describe 3 successful cases of oral surgery in patients with Glanzmann thrombasthenia and report the surgical and hematologic management of each case.