Platelet Counts In Immune Thrombocytopenia Patients Research Articles

Improvement of Platelet Count after Helicobacter Pylori Screening and Eradication in Immune Thrombocytopenia Patients: A Randomized Open-Label Study

Background:Helicobacter pylori (HP) has been known as a secondary cause of immune thrombocytopenia (ITP). Previous studies have demonstrated platelet count improvement after HP eradication in ITP. However, the impact of HP screening in adults with ITP remains unclear. Methods: We conducted a randomized open-label study to evaluate the benefit of HP screening to improve platelet count in ITP patients. Persistent or chronic ITP patients with ≥ 18 years of age who had platelet count below 150 x109/L were eligible. Patients were excluded if there were HIV or hepatitis C virus infection, active cancer, history of HP eradication within 1 year, or antibiotics/bismuth use within one month before enrollment. Patients were allocated in a 3:1 ratio to the HP screening arm or non-screening arm. Patients in the HP screening arm underwent 2 methods of HP screening: urea breath test (UBT) and HP serology test (Assure® H. pylori Rapid Test). Patients who had positive HP results by either test were received HP eradication with a 14-day course of proton pump inhibitor-based triple therapy. Treated patients were subsequently confirmed HP eradication by stool antigen test at 1 month. Dose modifications of treatments for ITP were allowed according to the treating physician's decision. Platelet count and 3-month cumulative dose of prednisolone were measured at baseline, 3 months, and 6 months. Quality of life using the Thai version of EQ-5D-5L was assessed at baseline and 6 months. The primary outcome was the mean difference in platelet count at 6 months. Key secondary outcomes were the prevalence of HP infection in adult ITP patients and improvement of EQ-5D-5L score at 6 months. Other outcome was the diagnostic accuracy of the HP serology test. Results: A total of 64 patients were enrolled. Forty-nine patients were assigned to the HP screening arm and 15 patients to the non-screening arm. Mean age was 47.2 years (SD 15.7). Fifty patients (78%) were female. Forty patients (62.5%) were using prednisolone with a mean dose of 8.5 mg/day. Mean platelet count at baseline was 73.8 x109/L (SD 29.5). Baseline characteristics were balanced (Table 1). All of the patients, except one, in the HP screening arm completed 2 methods of screening. Twenty-three of 48 patients had HP positive results by UBT, as a result, the prevalence of HP was 47.9%. All HP-positive patients completed an HP eradication course. One patient had a positive result of stool antigen test after HP eradication, which was successfully eradicated with levofloxacin-based treatment. At 6 months follow-up, patients in the HP screening arm had a significant improvement in platelet count as compared to baseline with a mean difference of 21.8 x109/L (95% CI 22.2 - 41.3, p=0.030) (Table 2). In addition, the EQ-5D-5L score revealed a significant improvement at 6 months as compared to baseline in the HP screening arm with a mean difference of 4.2 points (95% CI 0.8 - 7.6, p=0.016) (Table 2). Patients in the non-screening arm had no significant changes in platelet count or EQ-5D-5L score. A 3-month cumulative dose of prednisolone and dose adjustments of concomitant ITP treatments at 6 months in both arms were not significantly changed. Of 23 UBT-positive patients, only 11 patients had positive results with HP serology. All 25 UBT-negative patients also had negative results with HP serology. The sensitivity and specificity of the HP serology test were 47.8% and 100%, respectively. Conclusion: The prevalence of HP infection in adult Thai ITP patients was 47.9%. HP screening is effective in the improvement of platelet count and quality of life at 6 months in adult ITP patients with platelet count below 150 x 109/L. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Enhancing regulatory T-cell function via inhibition of high mobility group box 1 protein signaling in immune thrombocytopenia.

Primary immune thrombocytopenia (ITP) is the most common acquired autoimmune bleeding disorder. Abnormally increased levels of High Mobility Group Box 1 (HMGB1) protein associate with thrombocytopenia and therapeutic outcome in ITP. Previous studies proposed that a natural inhibitor of HMGB1, 18β-glycyrrhetinic acid (18β-GA), could be used for its anti-inflammatory and immune-modulatory effects, although its ability to correct immune balance in ITP is unclear. In this study, we showed that plasma HMGB1 correlated negatively with platelet counts in ITP patients, and confirmed that 18β-GA stimulated the production of regulatory T cells (Treg), restored the balance of CD4+ T-cell subsets and enhanced the suppressive function of Treg through blocking the effect on HMGB1 in patients with ITP. HMGB1 short hairpin RNA interference masked the effect of 18β-GA in Treg of ITP patients. Furthermore, we found that 18β-GA alleviated thrombocytopenia in mice with ITP. Briefly, anti-CD61 immune-sensitized splenocytes were transferred into severe combined immunodeficient mice to induce a murine model of severe ITP. The proportion of circulating Treg increased significantly, while the level of plasma HMGB1 and serum antiplatelet antibodies decreased significantly in ITP mice along 18β-GA treatment. In addition, 18β-GA reduced phagocytic activity of macrophages towards platelets both in ITP patients and ITP mice. These results indicate that 18β-GA has the potential to restore immune balance in ITP via inhibition of HMGB1 signaling. In short, this study reveals the role of HMGB1 in ITP, which may serve as a potential target for thrombocytopenia therapy.

HDAC3 single-nucleotide polymorphism rs2530223 is associated with increased susceptibility and severity of primary immune thrombocytopenia.

Primary immune thrombocytopenia (ITP) is an autoimmune hemorrhagic disorder characterized by a low platelet count and increased risk of bleeding. We previously reported that low-dose chidamide, a histone deacetylase (HDAC) inhibitor, restores immune tolerance in patients with ITP. This study aimed to evaluate the association of a single-nucleotide polymorphism (SNP) rs2530223 in the HDAC3 gene with susceptibility to ITP and its clinical features. Patients with ITP and age-matched healthy participants were recruited for this case-control study. Genotyping of the HDAC3 rs2530223 polymorphism was performed using MassARRAY platform. Individuals with T allele of HDAC3 rs2530223 exhibited a 1.472-fold increased risk of ITP susceptibility (OR 1.472; 95% CI 1.100-1.969; p=.009), while ones with the TT genotype under the codominant and recessive models, and the TC/TT genotypes under the dominant model all revealed increased risk of ITP susceptibility (dominant odds ratio[OR] 1.965; 95% CI: 1.046-3.656; p=.036; codominant OR 2.264; 95% CI 1.175-4.360; p=.015; and recessive OR 1.512; 95% CI 1.028-2.224; p=.036, respectively). Regarding platelet counts in ITP patients, we observed that the TC/TT genotypes exhibited a 3.932-fold increased risk for platelet (PLT) <30 × 109 /L (OR 3.932; 95% CI 1.426-10.842; p=.008). This study indicates that HDAC3 rs2530223 may be an important genetic factor related to ITP susceptibility and platelet count in ITP patients, providing new perspectives on disease progression, new therapeutic targets, and severity prediction.

N‐glycan profiling alterations of serum and immunoglobulin G in immune thrombocytopenia

BackgroundThe glycosylation alterations of serum and IgG are involved in a variety of autoimmune and inflammatory diseases and have shown great potential in biomarker field. The diagnosis of immune thrombocytopenia (ITP) is exclusive. Our study aimed to discover the potential glyco‐biomarkers for auxiliary diagnosis of ITP.MethodsThe serum samples were obtained from 61 ITP patients and 35 healthy controls, and IgG samples were purified from 34 out of 61 ITP patients and 35 healthy controls. DNA sequencer‐assisted fluorophore‐assisted carbohydrate electrophoresis (DSA‐FACE) was used to analyze serum and IgG N‐glycan profiling.Results6 of 12 serum N‐glycan peaks, 6 of 7 IgG N‐glycan peaks, serum fucosylation, and IgG galactosylation were significantly different between ITP patients and healthy controls (p < 0.05). IgG peak 7 showed good diagnostic efficacy for discriminating ITP patients from healthy individuals (AUC 0.967). ITP patients with severe thrombocytopenia had a significantly lower serum fucosylation than ITP patients with mild and moderate thrombocytopenia (p < 0.05). Serum fucosylation and serum peak 5 were correlated with platelet counts in ITP patients with severe thrombocytopenia, and the absolute values of correlation coefficient were both over 0.5.ConclusionsThe specific N‐glycan patterns of serum and IgG were observed in ITP patients. IgG peak 7 was a potential biomarker for auxiliary diagnosis of ITP.

The Effect of COVID-19 Vaccine in Patients with Immune Thrombocytopenia

▪Background: Immune thrombocytopenia (ITP) is an acquired autoimmune disorder against platelets characterized by a low platelet count and increased bleeding risk. ITP is likely to rise from defective immune tolerance in addition to a triggering event, such as vaccination. COVID-19 vaccination is associated with a small increased risk of development of de novo ITP. In patients historically diagnosed with ITP, relapse of thrombocytopenia after COVID-19 vaccination has been described. However, the precise platelet dynamics in previously diagnosed ITP patients after COVID-19 vaccination is unknownAims: To investigate the effect of the COVID-19 vaccine on platelet count, the occurrence of severe bleeding complications and necessity of rescue medication in patients historically diagnosed with ITP.Methods: Platelet counts of ITP patients and healthy controls were collected immediately before, 1 and 4 weeks after the first and second vaccination. Linear mixed effects modelling was applied to analyse platelet count dynamics over time.Results: We included 218 ITP patients (50.9% women) with a mean (SD) age of 58 (17) years and 200 healthy controls (60.0% women) with a mean (SD) age of 58 (13) years. Healthy controls and ITP patients had similar baseline characteristics (Table 1). 201/218 (92.2%)ITP patients received the mRNA-1273 vaccine, 16/218 (7.3%) the BNT162b vaccine and 1/218 (0.46%) the Vaxzevria vaccine. All healthy controls received the mRNA-1273 vaccine. Fifteen (6.8%) patients needed rescue medication (Table 1). Significantly more ITP patients who needed rescue medication were on ITP treatment prior COVID-19 vaccination compared to patients without exacerbation (56.2% (7/16) vs 27.4% (55/202), p=0.016).We found a significant effect of vaccination on platelet count over time in both ITP patients and healthy controls (Figure 1A). Platelet counts of ITP patients decreased 7.9% between baseline and 4 weeks after second vaccination (p=0.045). Rescue medication and prior treatment significantly increased platelet count over time (p=0.042 and p=0.044). Healthy controls decreased 4.5% in platelet count (p<0.001) between baseline and 4 weeks after second vaccination. There was no significant difference in platelet count between ITP patients and healthy controls (p=0.78) (Figure 2).IPT patients with a baseline platelet count of >150x10 9/L had a significant decrease of platelet count 4 weeks after second vaccination compared to baseline (median platelet count (IQR) 205 (94) vs 203 x10 9/L (109) p=0.001). No significant decrease was seen in ITP patients with a baseline platelet count <150 x10 9/L.Median (IQR) platelet counts were similar between patients with and without exacerbation, except for 4 weeks after second vaccination (112 (105) vs 45 x 10 9/L (70), p=0.025) (Figure 1B). No significant effect was observed over time in ITP patients with rescue medication (p=0.478) (Figure 1C). In ITP patients without rescue medication, COVID-19 vaccination had a significant effect over time (p=0.001), especially 1 week after second vaccination (Figure1B).Of the 15 patients who needed rescue medication, 8/15 patients (53.3%) received rescue medication within 4 weeks after first vaccination and 4/15 (26.67%) needed rescue medication after the first as well as after the second vaccination. 3/15 (20.0%) patients needed rescue medication after the second vaccination. In the total ITP population, 5/218 (2.2%) experienced a WHO grade 2-4 bleeding complication and 3/218 (1.4%) needed platelet transfusion. 4/5 (80%) bleedings occurred before the second vaccination. One of these patients had fatal varices bleeding, although platelet count was normal.Conclusion: COVID-19 vaccination has a significant effect on platelet count in ITP patients and healthy controls. In 6.8% of ITP patients rescue medication was needed and in 2.2% of ITP patients a WHO grade 2-4 bleeding occurred. The majority of rescue medication was given and the majority bleeding complications occurred in the 4 weeks after the first vaccination. Our results demonstrate that close monitoring of platelet count after COVID-19 vaccination is important in patients historically diagnosed with ITP. [Display omitted] DisclosuresWesterweel: Pfizer: Consultancy; BMS / Celgene: Consultancy; Incyte: Consultancy; Novartis: Research Funding. Levin: Roche, Janssen, Abbvie: Other: Travel Expenses, Ad-Board. Kruip: Bayer: Honoraria, Research Funding; Daiichi Sankyo: Research Funding. Jansen: Novartis: Consultancy, Other: Travel, Accommodations, Expenses; Advisory Board Novartis: Membership on an entity's Board of Directors or advisory committees; 3SBIO, Novartis: Other: Travel, accomodations, expenses.

The Relation between Serum Progranulin and Platelet Count in Immune Thrombocytopenia Patients.

Background: Immune thrombocytopenia (ITP) is an autoimmune disease with excessive platelet destruction and reduced platelet production. Progranulin (PGRN) has a protective effect against autoimmune diseases by competitive binding tumor necrosis factor-α receptors. Thus, we assessed the serum progranulin level in relation to platelet count in ITP patients, pre-and post-induction of corticosteroid therapy.Methods: A case – control study was conducted on 30 ITP patients and 30 apparently healthy subjects serving as acontrol group. Platelet count and serum progranulin levels were measured in newly diagnosed ITP patients before and 3−7 days after starting corticosteroid treatment.Results: The mean serum level of PGRN was significantly higher in ITP patients pre-treatment compared to healthy control subjects (P

Human Leukocyte Antigen-G Restores Immune Tolerance in Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is a common autoimmune bleeding disorder in which loss of immune tolerance leads to platelet destruction. Human leukocyte antigen-G (HLA-G) is a non-classical major histocompatibility complex class I antigen including four membrane-bound (mHLA-G, HLA-G1 to -G4) and three soluble (sHLA-G, HLA-G5 to -G7) isoforms due to alternative splicing of the HLA-G primary transcript. HLA-G exerts immunosuppressive functions by interacting with its inhibitory receptors, immunoglobulin-like transcripts (ILTs), expressing differentially on natural killer cells, T cells, and antigen presenting cells.Upon binding to ILTs, HLA-G suppressed lymphocyte proliferation, promoted apoptosis of cytotoxic lymphocytes and natural killer cells, inhibited antibody secretion from activated B cells, and induced expansion of suppressive T cells, tolerogenic dendritic cells and myeloid-derived suppressor cells. HLA-G supports immune escape, and high level of HLA-G is associated with unfavorable outcomes in cancer patients. Meanwhile, HLA-G-induced tolerance can benefit human allotransplantation and autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus, but the role of HLA-G in the treatment of ITP is still unclear.Here we observed significantly less soluble HLA-G in plasma from ITP patients positive for anti-glycoprotein (GP) IIb/IIIa and/or anti-GPIb/IX autoantibodies compared with autoantibody-negative patients or healthy controls. However, no significant difference was found in the sHLA-G levels between anti-glycoprotein (GP) IIbIIIa and anti-GPIb-IX autoantibodies groups. Interestingly, sHLA-G is positively correlated with platelet counts in ITP patients both with and without autoantibodies, suggesting that HLA-G can also protect platelets from destruction through other mechanisms. To elucidate this, we then analyzed both expression of membrane HLA-G and ILTs on PBMCs. Our data found less membrane-bound HLA-G and ILTs on CD4+T cells and CD14+cells in ITP patients. Moreover, recombinant human HLA-G (rhHLA-G) upregulated expression of ILT2 on CD4+and ILT4 on CD14+cells. The upregulation of ILT by rhHLA-G indicates that sHLA-G might also benefit ITP patients negative for anti-platelet autoantibodies.To determine whether rhHLA-G affects T cell differentiation, we tested 17 cytokines by ELISA to investigate the immune environment with or without rhHLA-G, and found that rhHLA-G upregulated Interleukin (IL)-4 and IL-10, and downregulated tumor necrosis factor-α, IL-12, and IL-17 secreted by ITP patient peripheral blood mononuclear cells (PBMCs), indicating a promotion of helper T(Th)2 and inhibition of Th1 and Th17 differentiation. However, our results indicated that rhHLA-G did not expand the CD4+CD25+Foxp3+regulatory T cells(Tregs). In addition, rhHLA-G exerted their immunosuppressive effects by upregulating IL-1β, IL-2, Granulocyte colony-stimulating factor (G-CSF), and granulocyte-macrophage colony stimulating factor (GM-CSF). By reprogramming the cytokine profile in ITP patients, HLA-G established an optimal environment for the impaired cell populations, such as dendritic cells (DCs), to regain their tolerogenic function. Our results showed that rhHLA-G inhibited monocyte-derived DCs maturation by downregulating CD80 and CD86 expression. To further assess whether the rhHLA-G modulated-DCs were functionally tolerogenic, PBMCs were then cocultured with rhHLA-G modulated-DCs. Our results showed that rhHLA-G-modulated DCs from ITP patients suppressed CD4+T cell proliferation by 38.8% compared to unmodulated cells. Besides, PBMCs exposed to rhHLA-G were less cytotoxic toward plateletsfrom ITP patients or healthy subjects. This study provides a potential strategy to protect exogenous platelets from destruction in ITP patients.In conclusion, our data demonstrated that impaired expression of HLA-G and/or ILT is involved in the pathogenesis of ITP, and recombinant human HLA-G can restore immune tolerance in ITP patients via upregulation of ILTs, which indicates that HLA-G can be a diagnostic marker and also a therapeutic option for ITP treatment. DisclosuresNo relevant conflicts of interest to declare.

Low platelet count as risk factor for infections in patients with primary immune thrombocytopenia: a retrospective evaluation

Infectious complications are common and sometimes life threatening in patients with immune thrombocytopenia (ITP), mainly due to the immune-suppressive therapy. Recent evidence suggests a potential role of platelets in the inflammation process. In this clinical study, we further investigated the role of thrombocytopenia on infections in patients with primary ITP. We retrospectively evaluated data from the recently published large randomized clinical trial of a cohort of 195 patients with primary ITP, who were randomized for prednisone or high-dose dexamethasone. From 158 patients (81%), data on platelet count and infections within the first month of treatment were collected. In this period, 24% of the ITP patients had an infection. Patients with infection had significant lower platelet counts during the first month of treatment leading to a significant lower therapy response at 1 month and a significant longer hospital stay (14.0 versus 9.8 days). Additionally, Cox regression analysis showed that an increase in platelet count of 20 × 109/L led to a reduction of 52% in infections in the next week, showing low platelet count is a significant risk factor for infection. Platelet transfusion led to an increase in platelet count in ITP patients without infection, but not in patients with infection. In conclusion, infections are common in patients with primary ITP leading to significant worse response rates and a longer hospital stay. Interestingly, low platelet count was independently correlated with an increased risk of infection.

Elevated Semaphorin 5A correlated with Th1 polarization in patients with chronic immune thrombocytopenia

BackgroundPrimary immune thrombocytopenia (ITP) is an immune-mediated disorder in which cellular immunity deficiency and disturbed cytokine profiles have been found. Semaphorin 5A (Sema5A) has been showed to be implicated in cellular immune response. We aimed to evaluate the role of Sema5A in patients with chronic ITP. MethodsPlasma levels of Sema5A, T helper (Th) cytokines (interferon [IFN] -γ,interleukin [IL]-4,IL-17A) were determined by enzyme-linked immunosorbent assay (ELISA) in ITP patients and healthy controls. Using real-time quantitative polymerase chain reaction (RT-PCR), mRNA levels of Sema5A and its receptor plexin-B3, plexin-A1 in peripheral blood mononuclear cells(PBMCs)were studied in all subjects. Specific anti-platelet autoantibodies were measured by the Pak Auto method. The dynamic change of plasma Sema5A and mRNA levels of its receptors was measured in 9 patients after effective therapy. ResultsPlasma Sema5A levels were significantly increased in active patients with chronic ITP compared to patients in remission and healthy controls. Elevated levels of Sema5A were found positively correlated with higher levels of plasma IFN-γ, IFN-γ/IL-4 ratio and negatively correlated with lower levels of plasma IL-4, platelet counts in ITP patients. The mRNA plexin-B3 was decreased in active ITP patients and inversely correlated with plasma Sema5A levels. Additionally, plasma levels of Sema5A and IFN-γ were reduced with up-regulation of plexin-B3 expression after effective treatment. ConclusionsOur data demonstrated elevated plasma Sema5A in chronic ITP patients might be involved in Th1 polarization by down-regulating receptor plexin-B3 expression and correlated with disease activity.

Induction of immune tolerance to platelet antigen by short-term thrombopoietin treatment in a mouse model of immune thrombocytopenia.

Immune thrombocytopenia (ITP) is an autoimmune disorder caused by IgG anti-platelet autoantibodies. Thrombopoietin (TPO) receptor agonists are highly effective in inducing the recovery of platelet counts in ITP patients. Although these agents are thought to promote platelet production without affecting the autoimmune pathogenesis of the disease, a small subset of ITP patients exhibits sustained platelet recovery after treatment termination. To investigate mechanisms involved in this sustained recovery, we evaluated the effects of short-term TPO treatment using a mouse ITP model generated by Foxp3(+) T regulatory cell (Treg) depletion. After treatment, platelet recovery was sustained, along with complete suppression of both anti-platelet autoantibody production and T-cell responses to platelet autoantigens. TPO treatment also promoted the peripheral induction of Foxp3(+) Tregs in conjunction with elevated circulating TGF-β levels. In summary, thrombopoietic agents are capable of inducing immune tolerance to platelet autoantigens, thereby suppressing the autoimmune pathogenesis of ITP.

Elevated expression of IL-12 and IL-23 in patients with primary immune thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired autoimmune disorder. Both impaired platelet production and T-cell-mediated effects play a role in ITP. A T-helper1 (Th1) polarization of the immune response and up-regulation of Th17 cells have been demonstrated in ITP patients. Interleukin (IL)-12 and IL-23 produced by antigen presenting cells are essential for inducing and sustaining Th1 and Th17 effector cells via different pathways. However, less is known with regard to the levels of expression and synthesis of these two cytokines in patients with ITP. This was determined in this study in 46 patients with ITP as well as in 22 healthy controls. Our results showed that an increased expression of IL-12 p40, IL-12 p35, and IL-23 p19 mRNA was observed in bone marrow mononuclear cells and peripheral blood mononuclear cells of patients with ITP compared with controls. Consequently, higher levels of IL-12 and IL-23 were also found in bone marrow plasma and peripheral blood plasma in patients with ITP than in controls. Afterwards, a markedly higher level of IL-12 and IL-23 in bone marrow plasma or peripheral blood plasma was found in patients with chronic ITP than in patients with acute ITP. Furthermore, the peripheral blood plasma levels of IL-12 and IL-23 were negative correlated with platelet counts in ITP patients. Therefore, the augmented expression of IL-12 and IL-23 in patients with ITP may play an important role in the pathogenesis of this disease.

Significance of Anti-GPIIb/IIIa Antibody in Efficacy of Eltrombopag for Patients with Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired hemorrhagic condition of accelerated platelet consumption caused by antiplatelet autoantibodies, and glycoprotein (GP)IIb/IIIa is one of the major target antigens recognized by platelet-reactive CD4+ T cells. Patients with ITP often have few bleeding symptoms despite very low platelet counts, suggesting that ITP platelets are highly functional. Several factors may contribute to the prothrombotic state in ITP. We investigated the effect of thrombopoietin (TPO)-receptor agonist (RA) on the procoagulant state in ITP with or without anti-GPIIb/IIIa antibody. Long-term administration of eltrombopag resulted in stabilization of platelet numbers in many patients. On the other hand, when the analysis was carried out according to the presence of GPIIb/IIIa autoantibodies, the increase in platelet counts in ITP patients was more significant with than without anti-GPIIb/IIIa autoantibodies. In addition, there were significant differences in PDMP between cases in which platelet count was above or below 100x109/l. Our observation is possible to reflect the role of the anti-GPIIb/IIIa antibody in ITP patients who received TPO-RA.

Telomerase Activity Increased and Telomere Length Shortened in Peripheral Blood Cells from Patients with Immune Thrombocytopenia

To evaluate the telomere/telomerase system and its clinical significance in immune thrombocytopenia (ITP) patients. A total of 237 ITP patients, 20 SLE patients and 200 age-and sex-matched healthy controls were included in this study. CD4(+), CD8(+) and CD19(+) lymphocytes were purified by magnetic beads sorting from peripheral blood of 37 active chronic ITP patients and 22 age-and sex-matched healthy controls. Telomerase activity was assayed by Telo TTAGGG Telomerase PCR ELISA KIT. The relative telomere length of peripheral blood mononuclear cell (PBMC) was measured by a quantitative polymerase chain reaction-based method (Q-PCR) from 200 ITP patients and 178 age-and sex-matched healthy controls. Telomerase activity was increased in CD4(+), CD8(+) and CD19(+) lymphocytes from ITP patients compared to those from healthy controls (p = 0.000). The level of telomerase activity in CD19(+) lymphocyte was higher than those in CD4(+) and CD8(+) lymphocytes. Telomerase activity of CD19+ lymphocytes had a modest negative correlation with platelet count in ITP patients (p = 0.042). The relative telomere length of PBMC in ITP patients was significantly shorter than that in the healthy controls (p = 0.002). Telomere length of PBMC in active ITP patients was significantly shorter than that in the controls (p = 0.000) and a tendency to be shorter even in inactive ITP patients (p = 0.065). Moreover, the telomere length in refractory and non-refractory ITP patients were both significantly shorter than that in the controls (p = 0.025; p = 0.000). However no significant difference in telomere length of PBMC was found between refractory ITP patients and non-refractory ITP patients (p = 0.234). An abnormal regulating telomere/telomerase system might be involved in the pathogenesis of ITP. Further studies may elucidate whether the telomere length could be considered as a predictive biomarker for the prognosis of ITP.

The experience of Flebogammadif® in primary immune thrombocytopenia

Primary immune thrombocytopenia (ITP) is a common autoimmune disease characterized by autoantibody-induced platelet destruction, suboptimal megakaryocytic production of platelets and consequent bleeding. Numerous controlled trials have proved that the administration of high-dose intravenous immunoglobulins (IVIG) results in rapid increases in the platelet numbers. Therefore, they are indicated in emergency settings or in patients needing surgical procedures. Here, the efficacy and safety of Flebogammadif®, a new high-purity IVIG, was assessed by an open, multi-centre, non-controlled, prospective study in 20 adult patients diagnosed with ITP for at least 6 months before recruitment and with a platelet count ≤ 20,000/µl before treatment. Patients received 0·4 g/kg/body weight of Flebogammadif® for 5 consecutive days and were followed-up for 3 months. There were three efficacy end-points: proportion of patients who reached a platelet count ≥ 50 000/µl; time for the platelet count to reach that level; and duration of response. Safety parameters [adverse events (AE), laboratory determinations and vital signs] and viral markers were monitored regularly. A total of 14 patients achieved a platelet count of ≥ 50,000/µl. The median time to platelet response was ≤ 2·5 days and the median number of days in which the platelet count remained ≥ 50,000/µl was ≥ 7·0 days. A regression of haemorrhages was reported for 17 patients on day 14. Eight patients presented 20 AEs (mainly mild) related potentially to the study drug. Neither abnormalities in laboratory values nor in viral markers were registered during the follow-up period. In conclusion, Flebogammadif® was well tolerated and succeeded in providing a haemostatic platelet count in ITP patients.