E Rossi

Incidence of the JAK2 V617F mutation among patients with splanchnic or cerebral venous thrombosis and without overt chronic myeloproliferative disorders

Summary.u2002 Background:u2002 Thrombosis of splanchnic or cerebral veins is a typical manifestation of polycythemia vera (PV) or essential thrombocythemia (ET). The recently identified Janus kinase 2 (JAK2) V617F somatic mutation is closely related to chronic myeloproliferative disorders (CMD).

The risk of thrombosis in patients with acute leukemia: occurrence of thrombosis at diagnosis and during treatment

Summary.u2002 Background:u2002Thromboembolism can occur during acute leukemia, especially acute lymphoid leukemia (ALL) treated with l‐asparaginase. Yet, most reports are anecdotical and scarce data are available on the risk of thrombosis in acute myeloid leukemia (AML). Objectives:u2002To evaluate the risk of thrombosis in patients with acute leukemia. Patients and methods:u2002Three‐hundred and seventy‐nine consecutive adult patients with newly diagnosed acute leukemia were recruited in an observational cohort study conducted from January 1994 to December 2003. Diagnosis was ALL in 69 patients, acute promyelocytic leukemia (APL; FAB subtype M3) in 31, and non‐M3 AML in 279. All first or recurrent symptomatic thromboembolic events objectively diagnosed were recorded. Results:u2002Twenty‐four patients of the overall 379 (6.3%; 95% CI 4.1%–9.2%) had a first thrombosis, venous in 80% of the cases and arterial in 20%. At diagnosis, thrombosis was a presenting manifestation in 13 cases (3.4% of the whole cohort): 1.4% in ALL, 9.6% in APL, and 3.2% in non‐M3 AML patients. Follow‐up was carried out on 343 patients without thrombosis at diagnosis and further 11 thrombotic events (3.2%) were recorded. At 6u2003months from diagnosis, the cumulative incidence of thrombosis was 10.6% in ALL, 8.4% in APL, and 1.7% in non‐M3 AML patients. The patients who received l‐asparaginase had a 4.9‐fold increased risk of thrombosis in comparison with those who did not (95% CI 1.5–16.0). The fatality rate due to thrombosis was 0.8%. Conclusions:u2002In patients with acute leukemia, the risk of thrombosis is not negligible. Thombosis can be a presenting symptom at diagnosis in a significant portion of cases with APL (9.6%) and non‐M3 AML (3.2%); a similar rate of thrombosis can occur during the subsequent course of the disease. The incidence of symptomatic thrombosis at diagnosis is relatively low in ALL patients (1.4%), but is significantly increased by further treatment up to 10.6%. Strategies of antithrombotic prophylaxis should be investigated in this setting.

Effect of Needle Type and Injection Technique on Pain Level and Vitreal Reflux in Intravitreal Injection

PURPOSEnTo evaluate the amount of reflux and degree of pain with intravitreal injection (IVT) using 6 different types of syringes/needles and 5 techniques of scleral incision, including 3 modifications of a beveled scleral incision.nnnMETHODSnThis was a study conducted in 205 eyes of 205 patients. IVT of bevacizumab for retinal pharmacotherapy with 6 types of needles and 5 techniques of scleral incision. The severity of subjectively evaluated pain (0-10) and the width of the subconjunctival bleb arising from the vitreal reflux. Secondary outcomes were increase in intraocular pressure and complication rate.nnnRESULTSnThe straight technique caused greater vitreal reflux than the beveled approaches, when compared individually or as a group (Pu2009<u20090.01). No difference in the severity of pain was found among all 5 types of incisions (Pu2009>u20090.05). There was greater reflux with 26- and 27-gauge needles in comparison to 29- and 30-gauge needles (Pu2009<u20090.001); however, the width of the needle significantly affected the degree of reflux only when using the nonbeveled incision (Pu2009<u20090.001). The patients injected with the 26- or 27-gauge needle experienced more pain matched to the 29- and 30-gauge needles (Pu2009<u20090.001). No difference was found between the incision technique or width of subconjunctival reflux and the increase in intraocular pressure (Pu2009>u20090.05). Postinjection events included transient mild uveitis, disease-related vitreous hemorrhage, foreign body sensation, conjunctival hemorrhage, and mild punctuate keratitis.nnnCONCLUSIONSnThe beveled scleral incision showed benefit in performing IVTs. The 29- and 30-gauge needles caused less pain.

A new global test for the evaluation of the protein C-protein S system.

We have developed a simple screening assay for evaluating the global activity of the protein C/protein S system. The new test consists of measuring the prothrombin time (PT) with bovine thromboplastin before and after activation of the PC present in the plasma sample by PROTAC, derived from Agkistrodon contortrix contortrix snake venom. Prolongation of the PT was directly related to the activity of the PC/PS system. One hundred and nineteen thrombophilic patients including 36 with PC deficiency, 22 with PS defect, 35 with APC resistance and 26 with other genetic defects predisposing to thrombosis were tested with the new assay together with 112 healthy subjects. The new test showed a high sensitivity for detection of inherited defects related to the PC/PS system (92%, 91% and 97% for PC defects, PS defects and APC resistance, respectively). Since it can be performed automatically the test could be used to screen for patients predisposed to thrombosis due to impairment of the PC/PS system and those patients who might eventually require more extensive evaluation of the PC/PS system by single component assays.

The G20210A prothrombin variant and the risk of venous thromboembolism or fetal loss in pregnant women: a family study.

Summary.u2002 Background:u2002 The relationship between the G20210A prothrombin variant (PT‐G20210A) and adverse pregnancy outcome has been studied by several groups in the last few years. However, because of the different design and sample sizes of these studies the estimated risks have varied.

High rate of recurrent venous thromboembolism in patients with myeloproliferative neoplasms and effect of prophylaxis with Vitamin K antagonists

The optimal duration of treatment with vitamin K antagonists (VKA) after venous thromboembolism (VTE) in patients with Philadelphia-negative myeloproliferative neoplasms (MPNs) is uncertain. To tackle this issue, we retrospectively studied 206 patients with MPN-related VTE (deep venous thrombosis of the legs and/or pulmonary embolism). After this index event, we recorded over 695 pt-years 45 recurrences, venous in 36 cases, with an incidence rate (IR) of 6.5 per 100 pt-years (95% confidence interval (CI): 4.9–8.6). One hundred fifty-five patients received VKA; the IR of recurrent thrombosis per 100 pt-years was 4.7 (95% CI: 2.8–7.3) on VKA and 8.9 (95% CI: 5.7–13.2) off VKA (P=0.03). In patients receiving VKA, the IR of recurrent thrombosis per 100 pt-years was 5.3 (95% CI: 3.2–8.4) among 108 patients on long-term VKA and 12.8 (95% CI: 7.3–20.7) after discontinuation among the 47 who ceased treatment (P=0.008), with a doubled risk of recurrence after stopping VKA (hazard ratio: 2.21, 95% CI: 1.19–5.30). The IR of major bleeding per 100 pt-years was 2.4 (95%: CI: 1.1–4.5) on VKA and 0.7 (95% CI: 0.08–2.5) off VKA (P=0.08). In conclusion, in MPN patients with VTE recurrent thrombosis is significantly reduced by VKA and caution should be adopted in discontinuation; however, the incidence of recurrence on treatment remains high, calling for clinical trials aimed to improve prophylaxis in this setting.

Fondaparinux in pregnancy: Could it be a safe option? A review of the literature.

During pregnancy thrombo-prophylaxis could be required in high risk women. If a severe allergic reaction to low-molecular-weight-heparin (LMWH) or a heparin-induced-thrombocytopenia (HIT) occurs, its mandatory to stop the drug. Fondaparinux could be an effective option. In the present review, the maternal and pregnancy outcomes of 65 pregnancies in women using Fondaparinux were reported. It was well-tolerated and rate of pregnancy complications was similar to that observed in general population. Regarding congenital malformations, further studies are necessary to investigate the safety of the drug.

Raman spectroscopy for differential diagnosis of endophthalmitis and uveitis in rabbit iris in vitro.

We developed a diagnostic tool to differentiate between endophthalmitis and uveitis using Raman spectroscopy. Twenty-two New Zealand rabbits with endophthalmitis induced by Staphylococcus aureus (10 animals), noninfectious uveitis induced by lipopolysaccharide from Escherichia coli (10 animals) and controls (two animals) were analyzed. Twenty-four hours after the eyes were inoculated, iris tissue was dissected and subjected to dispersive Raman spectroscopy using an excitation source at 830 nm and a spectrograph/CCD camera to detect a Raman signal with an integration time of 50 s. With the collected spectra of endophthalmitis and uveitis, we developed a routine to classify spectra in each specimen using principal components analysis, using a leave-one-out cross-validation procedure. The mean Raman spectra of tissues with uveitis and endophthalmitis showed several bands in the region of 800-1800 cm(-1), which have been attributed to nucleic acids, amino acids, proteins, and lipids. The bands at 1004, 1339, and 1555 cm(-1) differed significantly (t-test, p<0.05) between diseases. The principal components PC3 and PC4 differed significantly (ANOVA, p<0.05) for the two tissue types, indicating that these PCs can be used to discriminate between the two diseases using Mahalanobis distance as a discriminator. This technique is useful for differentiating the spectral bands of uveitis and endophthalmitis, and the diagnostic model showed sensitivity of 89%, specificity of 100%, and accuracy of 92% using the leave-one-out cross-validation procedure. These results may be clinically relevant for differentiating endophthalmitis from uveitis, and this approach may become a noninvasive method to optimize the diagnosis of inflammatory and infectious vitreoretinal diseases.

Differential diagnosis between experimental endophthalmitis and uveitis in vitreous with Raman spectroscopy and principal components analysis

Raman spectroscopy has been used for the diagnosis of various eye diseases. A diagnostic tool based on Raman spectroscopy has been developed to discriminate endophthalmitis from uveitis in vitreous tissues of rabbits eyes in vitro. Twenty-two New Zealand rabbits suffering from endophthalmitis induced by Staphylococcus aureus (n=10), non-infectious uveitis induced by lipopolysaccharide from Escherichia coli (LPS) (n=10 animals) and control (n=2) were included in the study. After eye inoculation, vitreous tissues were dissected and a fragment was submitted to dispersive Raman spectroscopy using near-infrared laser excitation (830 nm, 100 mW) and spectrograph/CCD camera for detection of Raman signal with integration time of 50 s. A routine was developed to classify the spectra of endophthalmitis and uveitis using principal components analysis (PCA) and Mahalanobis distance. The mean Raman spectra of tissues with uveitis and endophthalmitis showed several bands in the region of 800-1800 cm(-1), which have been attributed to nucleic acids, amino acids and proteins from inflamed tissue and proliferating bacteria. The bands at 1004, 1258, 1339, 1451 and 1635 cm(-1) showed statistically significant differences between both diseases. It was observed that principal components PC1, PC3 and PC4 showed statistically significant differences for the two tissue types, indicating that these PCs can be used to discriminate between the two groups. The diagnostic model showed 94% sensitivity, 95% specificity and 95% accuracy using PC3×PC4. The Raman spectroscopy technique has been shown to be useful in differentiating uveitis and endophthalmitis in vitreous tissues in vitro, and these results may be clinically relevant for differentiating vitreous tissues to optimise the diagnosis of inflammatory and infectious vitreoretinal diseases.

Reply to ‘Absence of JAK-2 (Val617Phe) point mutations in multiple myeloma’ by Dr Qin Huang et al. referred to ‘Screening of JAK2 V617F mutation in multiple myeloma’ from Fiorini A et al. published in Leukemia 2006, October 20

Reply to ‘Absence of JAK-2 (Val617Phe) point mutations in multiple myeloma’ by Dr Qin Huang et al. referred to ‘Screening of JAK2 V617F mutation in multiple myeloma’ from Fiorini A et al. published in Leukemia 2006, October 20