Background: The PLASMIC score is a convenient tool for predicting ADAMTS13 activity of ＜10%.Lactate dehydrogenase (LDH) is widely used as a marker of haemolysis in thrombotic thrombocytopenic purpura (TTP) monitoring, and could be used as a replacement marker for lysis. We aimed to validate the PLASMIC score in a multi-centre Asia Pacific region, and to explore whether LDH could be used as a replacement marker for lysis. Methods: Records of patients with thrombotic microangiopathy (TMA) were reviewed. Patients’ ADAMTS13 activity levels were obtained, along with clinical/laboratory findings relevant to the PLASMIC score. Both PLASMIC scores and PLASMIC-LDH scores, in which LDH replaced traditional lysis markers, were calculated. We generated a receiver operator characteristics (ROC) curve and compared the area under the curve values (AUC) to determine the predictive ability of each score. Results: 46 patients fulfilled the inclusion criteria, of which 34 had ADAMTS13 activity levels of ＜10%. When the patients were divided into intermediate-to-high risk (scores 5‒7) and low risk (scores 0‒4), the PLASMIC score showed a sensitivity of 97.1% and specificity of 58.3%, with a positive predictive value (PPV) of 86.8% and negative predictive value (NPV) of 87.5%. The PLASMIC-LDH score had a sensitivity of 97.1% and specificity of 33.3%, with a PPV of 80.5% and NPV of 80.0%. Conclusion Our study validated the utility of the PLASMIC score, and demonstrated PLASMIC-LDH as a reasonable alternative in the absence of traditional lysis markers, to help identify high-risk patients for treatment via plasma exchange.

Background/Aims: We evaluated the feasibility and long-term efficacy of the combination of cytarabine, idarubicin, and all-trans retinoic acid (ATRA) for treating patients with newly diagnosed acute promyelocytic leukemia (APL). Methods: We included 87 patients with newly diagnosed acute myeloid leukemia and a t(15;17) or promyelocytic leukemia/retinoic acid receptor alpha (PML-RARα) mutation. Patients received 12 mg/m2/day idarubicin intravenously for 3 days and 100 mg/m2/day cytarabine for 7 days, plus 45 mg/m2/day ATRA. Clinical outcomes included complete remission (CR), relapse-free survival (RFS), overall survival (OS), and the secondary malignancy incidence during a 20-year follow-up. Results: The CR, 10-year RFS, and 10-year OS rates were 89.7%, 94.1%, and 73.8%, respectively, for all patients. The 10-year OS rate was 100% for patients that achieved CR. Subjects were classified according to the white blood cell (WBC) count in peripheral blood at diagnosis (low-risk, WBC < 10,000/mm3; high-risk, WBC ≥ 10,000/mm3). The low-risk group had significantly higher RFS and OS rates than the high-risk group, but the outcomes were not superior to the current standard treatment (arsenic trioxide plus ATRA). Toxicities were similar to those observed with anthracycline plus ATRA, and higher than those observed with arsenic trioxide plus ATRA. The secondary malignancy incidence after APL treatment was 2.7%, among the 75 patients that achieved CR, and 5.0% among the 40 patients that survived more than 5 years after the APL diagnosis. Conclusions Adding cytarabine to anthracycline plus ATRA was not inferior to anthracycline plus ATRA alone, but it was not comparable to arsenic trioxide plus ATRA. The probability of secondary malignancy was low.

Venous thromboembolism (VTE), which includes pulmonary embolism and deep vein thrombosis, is a condition characterized by abnormal blood clot formation in the pulmonary arteries and the deep venous vasculature. It is often serious and sometimes even fatal if not promptly and appropriately treated. Moreover, the later consequences of VTE may result in reduced quality of life. The treatment of VTE depends on various factors, including the type, cause, and patient comorbidities. Furthermore, bleeding may occur as a side effect of VTE treatment. Thus, it is necessary to carefully weigh the benefits versus the risks of VTE treatment and to actively monitor patients undergoing treatment. Asian populations are known to have lower VTE incidences than Western populations, but recent studies have shown an increase in the incidence of VTE in Asia. A variety of treatment options are currently available owing to the introduction of direct oral anticoagulants.The current VTE treatment recommendation is based on evidence from previous studies, but it should be applied with careful consideration of the racial, genetic, and social characteristics in the Korean population.

Thrombotic microangiopathy (TMA) is defined by specific clinical characteristics, including microangiopathic hemolytic anemia, thrombocytopenia, and pathologic evidence of endothelial cell damage, as well as the resulting ischemic end-organ injuries. A variety of clinical scenarios have features of TMA, including infection, pregnancy, malignancy, autoimmune disease, and medications. These overlapping manifestations hamper differential diagnosis of the underlying pathogenesis, despite recent advances in understanding the mechanisms of several types of TMA syndrome. Atypical hemolytic uremic syndrome (aHUS) is caused by a genetic or acquired defect in regulation of the alternative complement pathway. It is important to consider the possibility of aHUS in all patients who exhibit TMA with triggering conditions because of the incomplete genetic penetrance of aHUS. Therapeutic strategies for aHUS are based on functional restoration of the complement system. Eculizumab, a monoclonal antibody against the terminal complement component 5 inhibitor, yields good outcomes that include prevention of organ damage and premature death. However, there remain unresolved challenges in terms of treatment duration, cost, and infectious complications. A consensus regarding diagnosis and management of TMA syndrome would enhance understanding of the disease and enable treatment decision-making.

Background/Aims: Seasonal variation is an environmental factor proposed to affect the incidence of venous thromboembolism (VTE). However, VTE seasonal variation is not well studied in Asian populations, which have different genetic determinants of VTE compared to Westerners. The present study aimed at investigating seasonal variation of VTE occurrence and the effect of various demographic factors (i.e., age, sex, and co-morbidities) on variation. Methods: VTE seasonal variation was evaluated in 59,626 index cases (from January 2009 to December 2013) in the Korean Health Insurance Review and Assessment Service database. We quantified and compared VTE occurrence across four seasons, and additionally assessed monthly through a chronobiological analysis. Results: VTE incidence varied both seasonally and monthly, with new cases peaking in the winter (January and February) and the lowest incidence in the summer (August and September). After adjusting for sex, age, type of VTE, and combined cancer diagnosis, winter remained a significant independent factor driving VTE incidence. Additionally, seasonal variation was prominent in patients aged 60 years or older and in patients with pulmonary embolism, but not so prominent in patients of aged less than 60 years and patients with deep vein thrombosis. Conclusions Seasonal variation was a weak but independent contributor to VTE incidence in a Korean population diagnosed from 2009 to 2013, especially in those individuals with old age or suffering from a pulmonary embolism.

Atypical hemolytic uremic syndrome (aHUS) is a rare syndrome characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute renal injury, which results from uncontrolled complement activation. Delayed diagnosis and treatment of aHUS may result in end-stage renal disease (ESRD) and an associated dependence on dialysis. In extreme cases, it may cause death due to multi-organ failure. Eculizumab, a humanized monoclonal antibody against C5, inhibits the formation of the terminal membrane attack complex and is used to treat aHUS. Here, we report a 46-year-old male patient who suffered from aHUS relapse, despite prior treatment with repeated plasma exchange and hemodialysis. Eculizumab therapy improved his hematologic findings without use of hemodialysis.

BACKGROUND/AIMS: Limited data are available regarding the efficacy of rivaroxaban for the treatment of cancer-associated venous thromboembolism (VTE). The aim of this study was to evaluate the effectiveness and safety of rivaroxaban for the treatment of VTE in active cancer patients. METHODS: In this prospective, multicenter, open-label trial (NCT01989845), we enrolled patients with active cancer and objectively diagnosed lower-extremity deep vein thrombosis, pulmonary embolism (PE), or both from November 2013 to June 2016. Active cancer was defined as a histologically confirmed malignancy, which was diagnosed or treated within the previous 6 months, or as a recurrent/metastatic cancer. Patients received oral rivaroxaban 15 mg twice daily for first 3 weeks, followed by 20 mg once daily for 6 months. The primary outcome was the symptomatic recurrent VTE and the secondary outcomes included any recurrent VTE, major or clinically relevant non-major (CRNM) bleeding events, and overall mortality. All study outcomes were validated by blinded central adjudication. RESULTS: Of 124 patients enrolled, 110 (88.7%) had solid cancer, 93 (75.0%) had metastatic disease, and 110 (88.7%) were receiving chemotherapy or radiotherapy. During the 6-month study period, seven patients experienced symptomatic recurrent VTE (cumulative incidence, 5.9%), and two patients experienced incidental recurrent PE (cumulative incidence of any recurrent VTE, 7.6%). Major bleeding events occurred in six patients (cumulative incidence, 5.3%) and CRNM bleeding events in 11 patients (cumulative incidence, 10.2%). Twenty-eight patients (overall mortality, 24.0%) died. CONCLUSIONS Rivaroxaban is effective and safe for the treatment of VTE in patients with active cancer.

BACKGROUND: Atypical hemolytic uremic syndrome (aHUS) involves dysregulation of the complement system, but whether this also occurs in thrombotic thrombocytopenic purpura (TTP) remains unclear. Although these conditions are difficult to differentiate clinically, TTP can be distinguished by low (<10%) ADAMTS13 activity. The aim was to identify the differences in complement activation products between TTP and aHUS and investigate ADAMTS13 activity as a prognostic factor in aHUS. METHODS: We analyzed patients with thrombotic microangiopathy diagnosed as TTP (N=48) or aHUS (N=50), selected from a Korean registry (N=551). Complement activation products in the plasma samples collected from the patients prior to treatment and in 40 healthy controls were measured by ELISA. RESULTS: The levels of generalized (C3a), alternate (factor Bb), and terminal (C5a and C5b-9) markers were significantly higher (all P<0.01) in the patients than in the healthy controls. Only the factor Bb levels significantly differed (P=0.008) between the two disease groups. In aHUS patients, high normal ADAMTS13 activity (≥77%) was associated with improved treatment response (OR, 6.769; 95% CI, 1.605–28.542; P=0.005), remission (OR, 6.000; 95% CI, 1.693–21.262; P=0.004), exacerbation (OR, 0.242; 95% CI, 0.064–0.916; P=0.031), and disease-associated mortality rates (OR, 0.155; 95% CI, 0.029–0.813; P=0.017). CONCLUSION: These data suggest that complement biomarkers, except factor Bb, are similarly activated in TTP and aHUS patients, and ADAMTS13 activity can predict the treatment response and outcome in aHUS patients.
Atypical Hemolytic Uremic Syndrome ; Biomarkers ; Complement Activation ; Complement System Proteins ; Enzyme-Linked Immunosorbent Assay ; Humans ; Mortality ; Plasma ; Purpura, Thrombotic Thrombocytopenic ; Thrombotic Microangiopathies

MYH9-related disorders (MYH9RD) are autosomal-dominant disorders characterized by macrothrombocytopenia with or without leukocyte inclusion bodies or extra-hematological features, such as sensorineural deafness and renal impairment. MYH9RD can be misdiagnosed as an acquired form of thrombocytopenia including immune thrombocytopenic purpura (ITP). This leads to delayed diagnosis or administration of ineffective treatment. In the present study, we investigated the clinical and molecular characteristics of five unrelated Korean patients with MYH9RD and their family members, from four institutions. We reviewed clinical and laboratory data including extra-hematological manifestations. MYH9 pathogenic variants were detected by direct sequencing in all probands and the affected family members (N=10): two probands with c.5521G>A (p.Glu1841Lys) and one proband each with c.99G>T (p.Trp33Cys), c.287C>T (p.Ser96Leu), and c.3493C>T (p.Arg1165Cys). All patients had macrothrombocytopenia. Only the proband with Ser96Leu had extra-hematological manifestations. Past history revealed that two patients had been misdiagnosed with ITP and one of them had received a splenectomy. We validated the frequency of misdiagnosis (~20%) and genotype-phenotype correlations through a comprehensive review of previously reported cases of MYH9RD in Korea. It is important to suspect MYH9RD in patients with thrombocytopenia, and timely identification of macrothrombocytopenia and MYH9 pathogenic variants is required for early and accurate diagnosis of MYH9RD.
Deafness ; Delayed Diagnosis ; Diagnosis ; Diagnostic Errors ; Genetic Association Studies ; Humans ; Inclusion Bodies ; Korea ; Leukocytes ; Purpura, Thrombocytopenic, Idiopathic ; Splenectomy ; Thrombocytopenia

BACKGROUND: In the current study, we aimed to investigate the efficacy and safety of intravenous immunoglobulin (IVIg)-SN 10%, a new 10% IVIg formulation, in adult patients with severe primary immune thrombocytopenia (ITP; platelet count < 20 × 109/L). METHODS: Patients diagnosed as primary ITP, aged 19 years old or more, and had a platelet count of < 20 × 109/L by screening complete blood cell count performed within 2 weeks of study commencement were eligible. Patients received IVIg-SN 10% at a dose of 1 g/kg/day for two consecutive days. Response was defined as the achievement of a platelet count of ≥ 50 × 109/L at day 8. RESULTS: Out of 81 eligible patients, 31 patients were newly diagnosed, 7 patients had persistent ITP, and 43 patients had chronic ITP. In intent-to-treat analysis, 61.3 patients (75.7%) achieved response and satisfied the pre-defined non-inferiority condition. Median time to response was 2 days and mean duration of maintaining response after the completion of IVIg therapy was 9.13 ± 8.40 days. Response rates were not found to be dependent on the phase of ITP or previous treatment for ITP. The drug was well tolerated and the frequency of mucocutaneous bleeding decreased during the study period. CONCLUSION: In summary, IVIg-SN 10% formulation was found to be safe and effective in adult ITP patients (Trial registry at ClinicalTrials.gov, NCT02063789).
Adult ; Blood Cell Count ; Hemorrhage ; Humans ; Immunoglobulins* ; Immunoglobulins, Intravenous ; Mass Screening ; Platelet Count ; Purpura, Thrombocytopenic, Idiopathic* ; Thrombocytopenia