Knockdown of the Shwachman-Diamond syndrome gene, SBDS, induces galectin-1 expression and impairs cell growth.

Shwachman-Diamond syndrome (SDS) is an autosomal recessive disorder characterized by exocrine pancreatic insufficiency and bone marrow failure. The depletion of SBDS protein by RNA interference has been shown to cause inhibition of cell proliferation in several cell lines. However, the precise mechanism by which the loss of SBDS leads to inhibition of cell growth remains unknown. To evaluate the impaired growth of SBDS-knockdown cells, we analyzed Epstein-Barr virus-transformed lymphoblast cells (LCLs) derived from two patients with SDS (c. 183_184TA > CT and c. 258 + 2 T > C). After 3 days of culture, the growth of LCL-SDS cell lines was considerably less than that of control donor cells. By annealing control primer-based GeneFishing PCR screening, we found that galectin-1 (Gal-1) mRNA expression was elevated in LCL-SDS cells. Western blot analysis showed that the level of Gal-1 protein expression was also increased in LCL-SDS cells as well as in SBDS-knockdown 32Dcl3 murine myeloid cells. We confirmed that recombinant Gal-1 inhibited the proliferation of both LCL-control and LCL-SDS cells and induced apoptosis (as determined by annexin V-positive staining). These results suggest that the overexpression of Gal-1 contributes to abnormal cell growth in SBDS-deficient cells.

Screening for M-proteinemia consisting of monoclonal gammopathy of undetermined significance and multiple myeloma for 30 years among atomic bomb survivors in Hiroshima.

Monoclonal gammopathy (M-proteinemia) is a premalignant plasma cell disorder. The prevalence of M-proteinemia increases with age and is affected by genetic or environmental factors. Atomic bomb (A-bomb) survivors in Hiroshima are in an age range when they are susceptible to M-proteinemia. The prevalence and incidence of M-proteinemia in Hiroshima A-bomb survivors were investigated for 30 years (1989-2018) to examine the influence of radiation exposure. The overall prevalence of M-proteinemia among 38,602 A-bomb survivors was 2.4%. M-proteinemia prevalence at age 70 years and monoclonal gammopathy of undetermined significance (MGUS) incidence were not associated with radiation exposure category. Males had a 2.30-fold higher prevalence and a 2.08-fold higher incidence than females. The risk of incidence for MGUS was 4.32-fold higher in persons aged < 10 years at the time of the A-bombing and 2.56-fold higher in those aged 10-19 years compared with those aged over 30 years. IgG type M-proteinemia was common and the IgM type developed 5-8 years later than other immunoglobulin types. Exposure to radiation was not clearly associated with the prevalence of M-proteinemia or incidence of MGUS in Hiroshima A-bomb survivors. However, males and those aged < 20 years at A-bombing had higher susceptibility to MGUS.

Risk factors for skin, mucosal, and organ bleeding in adults with primary ITP: a nationwide study in Japan.

Bleeding manifestations in primary immune thrombocytopenia (ITP) range from skin petechiae to life-threatening intracranial hemorrhage (ICH). However, the relation between these various bleeding manifestations and the platelet count in ITP remains poorly characterized. Using a nationwide database of patients with ITP during the years 2005 to 2014 (10 years) in Japan, we analyzed 19 415 adult patients newly diagnosed with ITP, including 222 with ICH. The frequency of skin purpura was 64.8%, and this increased linearly with thrombocytopenia without a specific platelet count threshold. In contrast, mucosal bleeding (epistaxis and gingival bleeding) and organ bleeding (melena, hematuria, and ICH) increased exponentially with thrombocytopenia at a platelet count threshold of 10 to 15 × 109/L. Age showed a much weaker correlation than platelet count with skin and mucosal bleeding. However, the incidence of organ bleeding increased exponentially above 60 years of age. Multivariate analysis showed that the presence of mucosal bleeding was a risk factor for occurrence of melena and hematuria but not for ICH. The frequency of ICH was 1.1% and risk factors for ICH were age ≥60 years (odds ratio [OR], 3.09; 95% confidence interval [CI], 2.13-4.47; P < .001), platelet count <10 × 109/L (OR, 2.96; 95% CI, 2.11-4.15; P < .001), and the presence of hematuria (OR, 1.56; 95% CI, 1.04-2.35; P = .033). The relation between ICH and platelet count varied with age. This large-scale analysis of risk factors for bleeding in ITP has revealed distinct characteristics of skin, mucosal, and organ bleeding in adult patients with newly diagnosed ITP, thus indicating those who are at a high risk of severe organ bleeding.

Efficacy and safety of rituximab in Japanese patients with relapsed chronic immune thrombocytopenia refractory to conventional therapy.

Primary immune thrombocytopenia (ITP) is an autoimmune disease mediated by the production of autoantibody against platelets. Rituximab, an anti-CD20 antibody, is reported to be useful for treatment of ITP. In Japan, however, robust evidence on this treatment has not been accumulated. Hence, we conducted this open-label phase III clinical trial to confirm the efficacy and safety of rituximab, administered at 375 mg/m² once per week at weekly intervals for 4 consecutive weeks in Japanese patients with chronic ITP, who had relapsed and were refractory to conventional therapy. The primary endpoint was defined as the percentage of patients with a platelet count above 50 × 109/L at week 24 after the first dose of rituximab, which was 30.8% of 26 patients (95% confidence interval 14.3-51.8%). Although the lower confidence limit of primary endpoint failed to meet the pre-specified threshold of 20%, the clinical efficacy of rituximab is substantial in consideration of the 2% response rate in the placebo arm in other clinical studies in patients with chronic ITP. We conclude that rituximab is clinically useful and safe in the treatment of Japanese patients with chronic ITP, achieving the goal of maintaining platelet count and reducing risk of bleeding while minimizing treatment-related toxicity.

[Idiopathic thrombocytopenic purpura].

In many extragastric manifestations with Helicobacter pylori (HP) infection, the most convincing evidences were observed in idiopathic thrombocytopenic purpura (ITP). The prevalence of HP infection in ITP was not different to general population. The high association of HP infection in ITP was reported in Italy and Japan but low in USA and UK. After eradication therapy, platelet counts response was found in over 50% of ITP cases in Japan and Italy, and about 40% in other countries. The platelet counts response following eradication was maintain for long time with drug free and the relapse case was rare. The platelet elevation reaction by eradication was not influenced by previous treatment, sex and age, but the disease duration as ITP and the platelet count before eradication were controversial factors. The main side effects of eradication were diarrhea, vomiting and skin rash. Based on these evidences, ITP guideline in Japan (2012) recommended that eradication therapy was the first choice treatment for HP positive ITP cases.

Successful perioperative management for a breast cancer patient with Bernard-Soulier syndrome.

We herein report the first case of a Bernard-Soulier syndrome (BSS) patient undergoing a surgical procedure for breast cancer. BSS is a rare hereditary thrombocytopathy associated with defects of the platelet glycoprotein complex glycoprotein Ib/V/IX and characterized by large platelets, thrombocytopenia, and severe bleeding symptoms. Because of the rarity of BSS, there are as yet no defined protocols for the perioperative management, which can be very complex and challenging in patients with coagulopathies, in particular BSS. In this case we successfully performed both an interventional examination as well as mastectomy with axillary lymph node dissection, under the preventive and intermittent transfusion of platelets. No intra- or postoperative bleeding complications occurred. Unfortunately, the patient was diagnosed as having metastatic disease involving liver, lungs, and bones 10 months after the surgery. She had received 1st, 2nd, and 3rd line chemotherapy without severe adverse events. However, gastrointestinal bleeding appeared after she was treated with 4th line chemotherapy. Finally, she succumbed 22 months after the breast surgery.

Mislocalization or low expression of mutated Shwachman-Bodian-Diamond syndrome protein.

Shwachman-Diamond syndrome (SDS) is an autosomal-recessive disorder characterized by exocrine pancreatic insufficiency and bone marrow failure. Mutations in the SBDS gene are identified in most patients with SDS. Recent studies have shown that SBDS is involved in ribosome biogenesis and is localized to the nucleolus. The significance of cellular localization in SBDS is unknown, particularly as SBDS does not exhibit canonical nuclear localization signals. In this study, we have constructed wild-type deletion mutants of the critical domains and disease-associated mutants of the SBDS gene. These constructs were expressed in HeLa cells to explore the subcellular distribution of normal and mutant proteins. Wild-type SBDS was detected in the nucleus. However, constructs lacking N-terminal Domain I and two disease-associated mutants (C31W and N34I) failed to localize SBDS to the nucleus. Moreover, the amount of mutated SBDS protein was decreased. When N-terminal Domain I was overexpressed in HeLa cells, the localization of endogenous SBDS protein was changed from nuclei to cytosolic fraction. These data indicate that the N-terminal Domain I is responsible for nuclear localization. Furthermore, low expression of SBDS, as exhibited in some of the disease-associated mutants, may be associated with the pathogenesis of SDS.

Epidemiology of primary immune thrombocytopenia in children and adults in Japan: a population-based study and literature review.

The epidemiology of primary immune thrombocytopenia (ITP) is not well-characterized in the general population. Most published studies, which have included relatively small numbers of ITP patients, have been conducted in England or Scandinavian countries. No epidemiologic data from Asian countries have been published. This study describes the epidemiology of ITP in a Japanese population. We analyzed the database registry of the Ministry of Health, Labour, and Welfare of Japan, and extracted newly diagnosed acute and chronic ITP patients with a platelet count of <100 × 10(9)/L. From 2004 to 2007, 7,774 cases of ITP were reported, giving an overall incidence of 2.16/100,000/year. The incidence differed greatly between males and females, being 1.72 and 2.58, respectively. The median age of the total affected population was 56 years old. In male patients, there was a striking preponderance of boys below 4 years and a very high peak among those aged 75-89 years. In female patients, the number of ITP patients appeared to show a trimodal distribution by age, with the first peak representing patients below 4 years, the second peak those aged 20-34 years, and the third peak those aged 50-89 years. In conclusion, the incidence of ITP in Japan is not markedly different from that of European countries studied to date. This population-based study reveals that, contrary to previously published studies, the maximum age-specific incidence is in the eighth decade.

Roles of Src-like adaptor protein 2 (SLAP-2) in GPVI-mediated platelet activation SLAP-2 and GPVI signaling.

BACKGROUND: Glycoprotein VI (GPVI) /Fc receptor gamma (FcRγ)-chain complex is one of the collagen receptors in platelets and responsible for the majority of the intracellular signaling events through a similar pathway to immune receptors. Src-like adaptor protein 2 (SLAP-2) is a recently characterized adaptor protein predominantly expressed in hematopoietic cells. In T cells, SLAP-2 was reported to associate with several tyrosine phosphorylated proteins, and function as a negative regulator of signaling downstream of T cell antigen receptor by virtue of its interaction with the ubiquitin ligase c-Cbl. But the data regarding the presence and role of SLAP-2 proteins in platelets is limited. OBJECTIVES: We describe the characterization of SLAP-2 in human platelets. METHODS: Human platelets were analyzed by Western blot analysis, immunoprecipitation, and pull down assay, etc. RESULTS: Immunoprecipitation revealed the presence of two forms of SLAP-2 with approximately 28 kD and 25 kD, and following stimulation of GPVI, the additional form with approximately 32 kD apppeared. We have found that upon GPVI activation, SLAP-2 translocated from the Triton X-100-soluble fraction to the Triton X-100-insoluble cytoskeleton fraction, with concomitant association with Syk, c-Cbl, and LAT. CONCLUSIONS: SLAP-2 appears to play a role in regulating signaling pathways by bringing important signaling molecules such as c-Cbl and Syk into proximity of cytoskeletal substrates. In platelets, SLAP-2 may have function as a negative regulator of GPVI-mediated signaling by interacting with c-Cbl, being similar to that reported in T cells.

Shwachman-Diamond syndrome is not necessary for the terminal maturation of neutrophils but is important for maintaining viability of granulocyte precursors.

OBJECTIVE: Shwachman-Diamond syndrome (SDS) is an autosomal-recessive disorder characterized by exocrine pancreatic insufficiency and bone marrow failure. The SDS disease locus was mapped to chromosome 7q11, and disease-associated mutations were reported in the Shwachman-Bodian-Diamond syndrome (SBDS) gene. SBDS is a member of a highly conserved protein family in diverse species including archaea and eukaryotes. It is widely expressed in many tissues, and its function is still unknown. To investigate the function of the SBDS protein, we undertook loss-of-function experiments in the 32Dcl3 cell line, which has the potential to differentiate to mature neutrophils. METHODS: SBDS gene was downregulated with lentivirus-based RNAi system. SBDS knockdown cells were analyzed for surface marker expression by flow cytometry and analyzed for the sensitivity to apoptosis-inducing stimuli. RESULTS: After culture in granulocyte colony-stimulating factor (G-CSF)-containing medium for 3 days, 32Dcl3 cells demonstrated normal proliferation but complete downregulation of SBDS protein expression. The SBDS RNAi knockdown cells did not proliferate in G-CSF-containing medium but after 7 days had the appearance of segmented neutrophils. The neutrophil maturation markers were detected on these cells. Undifferentiated SBDS RNAi knockdown cells demonstrated increased apoptosis of undifferentiated cells. Notably, SBDS RNAi knockdown cells demonstrated normal proliferation in interleukin-3-containing medium. CONCLUSION: We have established an SDS model cell line and have used this model to demonstrate that SBDS is not required for neutrophil maturation. However, SBDS knockdown cells were sensitive to apoptotic stimuli, indicating that SBDS acts to maintain survival of granulocyte precursor cells.

Immune response to CagA protein is associated with improved platelet count after Helicobacter pylori eradication in patients with idiopathic thrombocytopenic purpura.

BACKGROUND: Improvement in platelet counts has been reported after eradication of Helicobacter pylori in patients with idiopathic thrombocytopenic purpura (ITP). We examined the levels of serum markers of gastritis and anti-CagA (cytotoxin-associated gene A) IgG antibody in patients with ITP to investigate whether these factors are associated with the platelet response after H. pylori eradication therapy. MATERIALS AND METHODS: One hundred and sixteen consecutive patients with ITP were assessed for H. pylori infection by (13)C-urea breath test and serum H. pylori antibody test. Patients with H. pylori infection received eradication therapy. Before and after eradication therapy, we evaluated serum levels of gastrin, pepsinogen (PG)-I, and PG-II and the anti-CagA IgG antibody titer. RESULTS: H. pylori infection was found in 67 (58%) of the 116 patients with ITP. Fifty-two infected patients received eradication therapy, which was successful in 44 patients (85%). Twenty-seven patients (62%) showed an increased platelet count and were identified as responders. The duration of ITP was shorter in responders than in nonresponders (p = .017). There was no difference of the levels of gastrin and PGs between responders and nonresponders. Before eradication therapy, the serum anti-CagA antibody titer did not differ significantly between responders and nonresponders. However, reduction in the anti-CagA antibody titer after eradication therapy was significantly greater in responders than in nonresponders (p = .013). CONCLUSIONS: H. pylori eradication therapy improves the platelet count in H. pylori-positive patients with ITP of short duration. Immune response of hosts to CagA protein of H. pylori may play a role in the pathogenesis of ITP.

Patient characteristics in ticlopidine hydrochloride-induced liver injury: Case-control study.

BACKGROUND: Ticlopidine hydrochloride-induced liver abnormalities have been reported in the world. In Japan, the five-year (1995-2000) spontaneous serious reports of ticlopidine finds that liver injury accounts for about half of the reports. OBJECTIVE: Clinical characteristics of ticlopidine-induced liver injury were investigated to establish the prevention strategy. METHODS: We used a medical information system at Hiroshima University Hospital and analyzed statistically. RESULTS: In this study 288 cases were reviewed. Sixty-two cases were identified as the Cases that showed liver function abnormality after ticlopidine administration. And 226 cases were identified as the Controls. There were no significant differences in gender, age or daily dose between the two groups. Fluctuation of liver function was observed within 30 days in the most of Cases and cholestatic type accounted for about 60%. The risk of this abnormality increased significantly in patients with pre-existing abnormal liver or renal function [odds ratio (95% CI): 2.96 (1.43-6.13), p=0.005; 2.47 (1.13-5.39), p=0.037]. The renal protective agent, an oral carbonaceous adsorbent, reduced the risk of ticlopidine-induced liver function abnormalities in patients with renal abnormalities significantly [odds ratio (95% CI): 0.04 (0.002-0.767), p=0.004]. CONCLUSIONS: Liver function tests should be checked frequently, especially in cases with pre-existing liver or renal function abnormalities.

Helicobacter pylori infection and idiopathic thrombocytopenic purpura.

A treatment strategy for idiopathic thrombocytopenic purpura (ITP) is considered with the aim of cure or management of the bleeding tendency. In 1998, Gasbarrini et al reported a high prevalence of Helicobacter pylori infection in patients with ITP and showed that platelet recovery occurred after eradication therapy in most cases. Since then, many studies were performed to evaluate eradication therapy. This article discusses the incidence of H pylori infection in ITP, characteristic clinical features in H pylori-positive ITP, the effectiveness of eradication on platelet count increase, and the mechanisms of development of ITP by H pylori infection. Overall, there was a positive association between H pylori infection and ITP, and eradication of bacterium was accompanied by a significant increase in platelet counts in more than 50% of H pylori-positive ITP cases. These findings suggest that H pylori infection is involved in the mechanisms of thrombocytopenia in most cases of ITP in middle-aged and older patients. This approach could be beneficial to some ITP patients, but there were some uncertainties raised. To confirm the effectiveness of eradication therapy in H pylori-positive ITP, prospective studies conducted in several countries with a new treatment protocol are required, with a large number of ITP cases and longer follow-up.

Is eradication therapy useful as the first line of treatment in Helicobacter pylori-positive idiopathic thrombocytopenic purpura? Analysis of 207 eradicated chronic ITP cases in Japan.

A retrospective study was performed to determine the prevalence of Helicobacter pylori (H pylori) infection, the effect of H pylori eradication on platelet counts, and the characteristic clinical features of chronic immune or idiopathic thrombocytopenic purpura (ITP) with H pylori infection. H pylori infection was found in 300 patients, a group that was significantly older (P < .005) and had more cases of hyperplastic megakaryocytes in the bone marrow (P = .01) than patients without H pylori infection. H pylori eradication therapy was performed in 207 H pylori-positive ITP cases, and the platelet count response was observed in 63% of the successful eradication group and in 33% of the unsuccessful eradication group (P < .005). In the successful group, the complete remission and partial remission rates were 23% and 42%, respectively, 12 months after eradication. In the majority of responders, the platelet count response occurred 1 month after eradication therapy, and the increased platelet count continued without ITP treatment for more than 12 months. H pylori eradication therapy was effective even in refractory cases, which were unresponsive to splenectomy. In conclusion, H pylori infection was involved in most ITP patients older than 40 years in Japan, and eradication therapy should be the first line of treatment in H pylori-positive ITP patients.