Whole exome sequencing and rare variant association study to identify genetic modifiers, KLF1 mutations, and a novel double mutation in Thai patients with hemoglobin E/beta-thalassemia

OBJECTIVES

Clinical manifestations of patients with Hemoglobin E/beta-thalassemia vary from mild to severe phenotypes despite exhibiting the same genotype. Studies have partially identified genetic modifiers. We aimed to study the association between rare variants in protein-coding regions and clinical severity in Thai patients.

METHODS

From April to November 2018, a case-control study was conducted based on clinical information and DNA samples collected from Thai patients with hemoglobin E/beta-thalassemia over the age of four years. Cases were patients with severe symptoms, while patients with mild symptoms acted as controls. Whole exome sequencing and rare variant association study were used to analyze the data.

RESULTS

All 338 unrelated patients were classified into 165 severe and 173 mild cases. Genotypes comprised 81.4% of hemoglobin E/beta-thalassemia, 2.7% of homozygous or compound heterozygous beta-thalassemia, and 0.3% of (δβ)⁰ thalassemia Hb E while 15.7% of samples were not classified as beta-thalassemia. A novel cis heterozygotes of IVS I-7 (A > T) and codon 26 (G > A) was identified. Six genes (COL4A3, DLK1, FAM186A, PZP, THPO, and TRIM51) showed the strongest associations with severity (observed p-values of <0.05; significance lost after correction for multiplicity). Among known modifiers, KLF1 variants were found in four mild patients and one severe patient.

CONCLUSION

No rare variants were identified as contributors to the clinical heterogeneity of hemoglobin E/beta-thalassemia. KLF1 mutations are potential genetic modifiers. Studies to identify genetic factors are still important and helpful for predicting severity and developing targeted therapy.

Direct oral anticoagulants versus low-molecular-weight heparins for the treatment of acute venous thromboembolism in patients with gastrointestinal cancer: a systematic review and meta-analysis

Background

The association between gastrointestinal (GI) cancer and a high incidence of venous thromboembolism (VTE) is well known. Previous randomized controlled studies demonstrated that direct oral anticoagulants (DOACs) effectively treat cancer-associated thrombosis (CAT). However, some DOACs appeared to increase the risk of bleeding, particularly in patients with GI malignancies. Therefore, the current systematic review and meta-analysis were conducted to evaluate the safety and efficacy of DOACs in GI cancer-associated thrombosis.

Methods

Two investigators individually reviewed all studies that compared DOACs and low-molecular-weight heparins (LMWHs) in GI cancer-associated thrombosis and were published in MEDLINE and EMBASE before February 2022. The effect estimates and 95% confidence intervals (CIs) from each eligible study were combined using the Mantel–Haenszel method.

Results

A total of 2226 patients were included in the meta-analysis. The rates of major bleeding in the DOAC and LMWH groups were not significantly different (relative risk [RR]: 1.31; 95% CI: 0.84–2.04; P = 0.23; I² = 41%). However, the rate of clinically relevant nonmajor bleeding (CRNMB) was significantly higher in the DOAC group (RR: 1.76; 95% CI: 1.24–2.52; P = 0.002; I² = 8%). The risks of recurrent VTE in the groups did not significantly differ (RR: 0.72; 95% CI: 0.49–1.04; P = 0.08; I² = 0%).

Conclusions

The current data suggest that treatment of GI cancer-associated thrombosis with DOACs significantly increases the risk of CRNMB. However, the risk of major bleeding was not significantly different. The efficacy of DOACs for preventing recurrent VTE in GI cancer was comparable to that of LMWHs.

Trial registration

INPLASY202180113.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-022-00399-7.

Thrombotic and Hemorrhagic Incidences in Patients After Discharge from COVID-19 Infection: A Systematic Review and Meta-Analysis

Background

The association between coronavirus infection 2019 (COVID-19) and thrombosis has been explicitly shown through numerous reports that demonstrate high rates of thrombotic complications in infected patients. Recently, much evidence has shown that patients who survived COVID-19 might have a high thrombotic risk after hospital discharge. This current systematic review and meta-analysis was conducted to better understand the incidence of thrombosis, bleeding, and mortality rates among patients discharged after COVID-19 hospitalization.

Methods

Using a search strategy that included terms for postdischarge, thrombosis, and COVID-19, 2 investigators independently searched for published articles indexed in the MEDLINE, Embase, and Scopus databases that were published before August 2021. Pooled incidences and 95% confidence intervals were calculated using the DerSimonian-Laird random-effects model with a double arcsine transformation.

Results

Twenty articles were included in the meta-analysis. They provided a total of 19 461 patients discharged after COVID-19 hospitalization. The weighted pooled incidence of overall thrombosis among the patients was 1.3% (95 CI, 0. 6-2; I² 90.5), with a pooled incidence of venous thrombosis of 0.7% (95 CI, 0. 4-1; I² 73.9) and a pooled incidence of arterial thrombosis of 0.6% (95 CI, 0. 2-1; I² 88.1). The weighted pooled incidences of bleeding and mortality were 0.9% (95 CI, 0. 1-1.9; I² 95.1) and 2.8% (95 CI, 0. 6-5; I² 98.2), respectively.

Conclusions

The incidences of thrombosis and bleeding in patients discharged after COVID-19 hospitalization are comparable to those of medically ill patients.

Human herpesvirus 8-associated multicentric Castleman disease in a patient with advanced HIV infection: A case report

RATIONAL

Multicentric Castleman disease (MCD) is a nonclonal lymphoproliferative disorder that is rarely reported from Southeast Asian countries. Here, we report a case of human herpesvirus 8 (HHV-8)-associated MCD in a patient with advanced human immunodeficiency virus (HIV) infection who presented with prolonged intermittent fever, urticarial rash, hepatosplenomegaly, and generalized lymphadenopathy.

PATIENT CONCERNS

A 34-year-old man with advanced HIV infection who was in good compliance with his antiretroviral treatment regimen presented with intermittent fever, weight loss, marked hepatosplenomegaly, and generalized lymphadenopathy. Recurrent symptoms of high-grade fever, abdominal discomfort, pancytopenia, and high C-reactive protein level occurred for 16 months.

DIAGNOSES

Histopathological findings of left inguinal lymph node revealed diffuse effacement of lymph node architecture with coexpression of HHV-8 latency-associated nuclear antigen 1 from immunohistochemical staining. The HHV-8 viral load was 335,391 copies/mL.

INTERVENTIONS

The patient was treated initially with one dose of intravenous rituximab (375 mg/m2) followed by subcutaneous rituximab (1400 mg) weekly for 5 weeks.

OUTCOMES

The patient's recurrent systemic symptoms subsided dramatically, and he has now been in remission for almost two years.

LESSONS

HHV8-associated MCD remains a diagnostic challenge in advanced HIV disease and should be suspected in those with recurrent flares of systemic inflammatory symptoms. Lymph node histopathology is essential for diagnosis and for excluding clonal malignancy. HHV-8 viral load is also useful for diagnosis and for monitoring disease activity.

Spontaneous heparin-induced thrombocytopaenia with adrenal haemorrhage following orthopaedic surgery: a case report and literature review

A 68-year-old woman was admitted to the hospital for elective total knee arthroplasty in both knees without preceding heparin exposure. She developed adrenal haemorrhage and thrombocytopaenia on postoperative day 12, followed by right leg arterial occlusion and multiple venous intra-abdominal sites thrombosis. After given unfractionated heparin to treat arterial occlusion, platelet count was gradually declined. Spontaneous heparin-induced thrombocytopaenia was diagnosed by heparin-induced platelet activation test with light transmission aggregometry. The patient was successfully treated with fondaparinux and intravenous immunoglobulin. Apixaban was given after recovery of platelet count. Resolution of both thrombus along aorta and adrenal haemorrhage were shown by CT of whole abdomen after 2 months of treatment. Our case demonstrates that this serious complication is important but seldom recognised early.

Successful Treatment of Factor X Deficiency in a Patient with Lymphoplasmacytic Lymphoma with Bendamustine Plus Rituximab Regimen: A Case Report and Literature Review

Background

Acquired factor X deficiency is an uncommon condition, and affected individuals have severe and spontaneous bleeding. The associated conditions include malignancy, infection, burn, and inflammatory bowel disease. Many previous studies reported association between lymphoproliferative disease and factor X disappearance. Amyloid deposition causing factor X absorption was the most common mechanism. Here, we report a case of stage IV lymphoplasmacytic lymphoma (LPL) with factor X deficiency who was successfully treated with bendamustine plus rituximab (BR) regimen.

Case Presentation

A 52-year-old Thai woman presented with heavy menorrhea, hoarseness, and widespread ecchymosis at her extremities. On physical examination, the patient had bilateral periorbital purpura and vocal cord hematoma. Coagulation testing showed prolonged prothrombin time (PT) and prolonged activated thromboplastin time (aPTT); however, after mixing with 1:1 normal pooled plasma, PT and aPTT were both corrected to normal levels. Factor assays demonstrated markedly decreased factor X levels, but no presence of factor X inhibitor. Bone marrow examination revealed numerous abnormal lymphoplasmacytoid lymphocytes with kappa light chain expression. Serum free light chain assay also showed kappa light chain restriction [kappa 716.16 mg/L, lambda 16.96 mg/L, ratio 42.23 (0.26–1.65)]. The patient was diagnosed as lymphoplasmacytic lymphoma with factor X deficiency. She received chemotherapy with 6 cycles of bendamustine plus rituximab (BR) regimen. The patient responded favorably to treatment, she remains in lymphoma remission at one year after diagnosis, and her factor X level was more than 20%.

Conclusion

We performed a literature review to identify previous case reports about lymphoma-associated factor X deficiency or inhibitor to determine a possible explanation in our patient. It is important to emphasize that when patients present with acquired factor deficiency, including factor X, lymphoproliferative disease is commonly one of the underlying conditions. Furthermore, the recovery of coagulation factor deficiency is possible if successful remission of lymphoma can be achieved.

Successful venous thromboprophylaxis in a patient with vaccine-induced immune thrombotic thrombocytopenia (VITT): a case report of the first reported case in Thailand

BACKGROUND

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare but fatal complication of the Coronavirus Disease 2019 vaccine. The many reports of VITT have mostly been in the Caucasian population. Here, we present the first reported case in an Asian population.

CASE PRESENTATION

A 26-year-old female had severe headache and severe thrombocytopenia 8 days after administration of the ChAdOx1 nCoV-19 vaccine developed by AstraZeneca. Although no thrombosis was demonstrated by imaging studies, she had very highly elevated d-dimer levels during hospitalization. Serology for antibodies against platelet factor 4 was positive on several days with very high optical density readings. We found that the antibody could induce spontaneous platelet aggregation without the presence of heparin. We decided to treat her with intravenous immunoglobulin, high-dose dexamethasone, and a prophylactic dose of apixaban. She improved rapidly and was discharged from the hospital 6 days after admission. Neither thrombocytopenia nor thrombosis was subsequently detected at the three-week follow-up.

CONCLUSIONS

Despite the lower rate of thrombosis, VITT can occur in the Asian population. Early detection and prompt treatment of VITT can improve the patient's clinical outcome. Thromboprophylaxis with nonheparin anticoagulants also prevents clot formation.

Sensitivity and specificity of 20-minute whole blood clotting test, prothrombin time, activated partial thromboplastin time tests in diagnosis of defibrination following Malayan pit viper envenoming

Malayan pit vipers (Calloselasma rhodostoma) are major health hazard in Southern Thailand causing systemic bleeding by defibrination and thrombocytopenia. Twenty minute whole blood clotting test (20WBCT) is a useful and informative bedside test recommended by WHO for diagnosis of significant coagulopathy following snakebite envenoming since it to some extent predicts the need for anti-venom therapy. Prothrombin time (PT), international normalized ratio (INR) and activated partial thromboplastin time (APTT) are standard clotting assays that are widely used for diagnosis of coagulopathy. The purpose of this study is to compare 20WBCT with the standard clotting assays (PT, INR, APTT, fibrinogen) in management of Malayan pit viper bitten-patients. We studied 296 victims prospectively during a 3-year period. In total, 115 (38.9%) cases showed a positive 20WBCT (un-clot) suggesting systemic envenomation. Thrombocytopenia (platelet count less than 100,000/μL), prolonged PT, prolonged APTT, INR ≥ 1.2, and fibrinogen level <100 mg/dl were found in 12.2%, 47.6%, 18.9%, 34.8% and 40.9%, respectively. Significant predictors for thrombocytopenia by multivariate analysis included systemic bleeding (p < 0.001), higher INR (p < 0.001), 20WBCT showing unclotted blood (p = 0.049), and longer bite-to-hospital time (p = 0.031). When a fibrinogen level below 100 mg/dl was determined as hypofibrinogenemic condition, INR had the highest area under ROC curve followed by 20WBCT and APTT, respectively, to identify such as hypofibrinogenemic condition. The diagnostic accuracy of 20WBCT and INR at or more than 1.155 were better than APTT at any cut-off points. INR >1.155 had a sensitivity of 78.5% and specificity of 90.3% while 20WBCT had sensitivity of 81.0% and specificity of 90.3%. CONCLUSIONS: Both 20WBCT and INR are useful to assess coagulation abnormality in Malayan pit viper-bitten patients.

Efficacy and Safety of Metronomic Chemotherapy Versus Palliative Hydroxyurea in Unfit Acute Myeloid Leukemia Patients: A Multicenter, Open-Label Randomized Controlled Trial

Background:

Management of unfit AML patients is a therapeutic challenge. Most hematologists tend to avoid aggressive treatment leaving patients with a choice of best supportive care. We hypothesized that metronomic chemotherapy could be an alternative treatment for unfit AML patients.

Methods:

A multi-center randomized controlled trial was conducted in seven university-affiliated hospitals in Thailand. Unfit AML patients were recruited and followed up from December 2014 to December 2017. Patients were randomly assigned to receive either metronomic chemotherapy or palliative hydroxyurea. Overall survival rates were compared using Cox’s proportional hazard survival analysis.

Results:

A total of 81 eligible patients were randomly allocated and included for ITT analysis. The OS rate was higher in group receiving metronomic chemotherapy than in group receiving palliative treatment at 6 and 12 months with borderline significance (6 months HR 0.60; 95%CI 0.36, 1.02; p-value 0.060; 12 months: HR 0.66; 95%CI 0.41, 1.08; p-value 0.097).

Conclusion:

Metronomic chemotherapy could prolong survival time of unfit AML patients, especially in the first 12 months after diagnosis without increasing treatment-associated adverse events.

Comparison between optical microscopy and the Sysmex XN-3000 for schistocyte determination in patients suspected of having schistocytosis

Background and aims

Diagnosis of thrombotic microangiopathy (TMA) relies on microscopic schistocyte determination by an experienced microscopist. In addition, schistocytes can be found in non‐TMA–related disorders such as thalassaemia. We aimed to compare the accuracy of the automated haematology analyser Sysmex XN‐3000 for schistocyte detection, to that of the microscopy approach, in patients suspected of having schistocytosis.

Methods

Consecutive blood samples were collected between April 2016 and March 2017 at Siriraj Hospital, Mahidol University, Bangkok, Thailand. Specimens were collected from adults with suspected TMA or with thalassaemia trait and/or disease. All blood samples were examined by both microscopy and the analyser. Samples were considered to be positive for schistocytes (ie, schistocytosis) if they had a schistocyte count ≥1% by microscopy. The analyser's ability to determine schistocytosis was assessed by receiver operating characteristic (ROC) curve. Sensitivity, specificity, positive (PPV), and negative predictive value (NPV) of an appropriate cut‐off point were calculated, with manual microscopy as the standard. Quantitative agreement in schistocyte counts between the two approaches was assessed using 95% limits of agreement, Bland‐Altman plots, intraclass correlation coefficient, and concordance correlation coefficient.

Results

Ninety‐seven blood samples (62 suspected TMA and 35 thalassaemia) were collected. ROC curve analysis of the analyser for determining schistocytosis showed an area under the curve of 0.803 (95% confidence interval, 0.689‐0.917, P < 0.001). A cut‐off point of 0.6% yielded 86.1% sensitivity, 77.8% specificity, 94.4% PPV, and 56.0% NPV. The automated schistocyte count did not quantitatively agree with schistocyte counts by microscopy, neither in all blood specimens (mean of difference: −1.09; 95% limits of agreement, −11.9 to 9.7) nor in the subgroups (TMA, −0.88; 95% limits of agreement, −6.60 to 4.84; thalassaemia, −2.4; 95% limits of agreement, −14.10 to 9.30). The differences in the estimation of fragmented red blood cells between the methods tended to increase at higher schistocyte counts.

Conclusion

Sysmex XN‐3000 can be used for qualitative measurement of schistocytosis, but should not be used as a quantitative tool for schistocyte counting. Improvements are needed before this analyser's schistocyte detection feature can be recommended for use in clinical practice.

Determination of Normal HbA1C Levels in Non-Diabetic Patients with Hemoglobin E

OBJECTIVE

Hemoglobin E (Hb E) possesses an influence on HbA1c levels. Careful interpretation of HbA1c is needed in areas with a high prevalence of Hb E, including Thailand. Therefore, the normal levels of HbA1c in non-diabetic Hb E subjects were collected and assessed.

METHODS

A cross-sectional study was conducted in Hb E subjects aged 18 years and above (N=70). An oral glucose tolerance test was performed. HbA1c levels were measured with 3 assays: ion exchange HPLC, immunoassay (ImmA), and enzymatic assay (EnzA). Individuals who received regular blood transfusions and diabetic patients were excluded.

RESULTS

Among 34 subjects with heterozygous Hb E (EA), the mean (±SD) HbA1c levels by HPLC, ImmA, and EnzA were 5.63±0.55%, 4.73±0.62%, and 5.29±0.37%, respectively. Among 29 subjects with homozygous Hb E (EE), the mean (±SD) HbA1c levels by HPLC, ImmA, and EnzA were 3.37±0.69%, 4.37±0.76, and 4.91±0.28%, respectively. Immunoassay and enzymatic methods seem preferable over HPLC for this population. The HbA1c level of 5.7 (99^th percentile) from immunoassay is a proposed cut-off point for detecting individuals who are at an increased risk of diabetes.

CONCLUSION

There are subjects with hemoglobin E whose HbA1c levels are deemed inaccurate due to the techniques used. Within this study normal HbA1c levels were determined by 3 different assays. The HbA1c level of 5.7 by immunoassay (Advia, 1600) is proposed as the cut-off point for diagnosing subjects at risk of diabetes.

Efficacy and safety of second-line treatment in Thai patients with primary warm-type autoimmune hemolytic anemia

Objectives:: To investigate the efficacy and safety of second-line treatment in Thai patients with primary warm-type autoimmune hemolytic anemia (AIHA) that failed corticosteroid treatment. Methods:: This descriptive retrospective study included patients aged >14 years who were diagnosed with and treated for primary warm-type AIHA at the Division of Hematology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, during January 2007 to December 2016. All 54 included patients failed first-line corticosteroid treatment after which second-line treatment was prescribed. Baseline clinical characteristics, laboratory results at diagnosis and at start of second-line treatment, type of second-line treatment, treatment outcome, and complications of treatment including death were collected. Results:: Included patients had a mean age at onset of 55.8 years (14.5-87.4) and 83.3% of patients were female. Most patients (63%) were refractory to steroids, and the rest of them relapsed while on steroids. The second-line medications were azathioprine (61.1%), cyclophosphamide (31.5%), chlorambucil (1.9%), danazol (3.7%), and rituximab (1.9%), with respective response rates of 78.8%, 58.8%, 1/1 patient, 2/2 patients, and 0/1 patient. Strong positive direct Coombs' test (3+-4+) was the only predictive factor of treatment response (p = 0.008). Males had better relapse-free survival than females (not reached vs. 20.6 months) (p = 0.023). Approximately 40% of the patients who responded to second-line treatment relapsed at a median of 7.4 months. Conclusion:: Immunosuppressive drugs are the most common second-line treatment for primary warm-type AIHA in Thailand; however, relapse was common. Additional therapies are needed to reduce the relapse rate and prolong remission.

Random skin biopsy in the diagnosis of intravascular lymphoma

BACKGROUND

Random skin biopsy (RSB) is a method for diagnosis of intravascular lymphoma (IVL). However, the indications for RSB to diagnose IVL have not yet been established. The aim of this study was to determine the appropriate indications for RSB to diagnose IVL.

METHODS

Thirty-two patients with fever of unknown origin (FUO) and without skin lesion underwent RSB for diagnosis of IVL. Clinical data, including fever, neurological symptoms, hematologic disorders, organomegaly, bone marrow (BM) study, hypoxemia and serum level of lactate dehydrogenase (LDH), were evaluated.

RESULTS

Seven of 32 patients were definitively diagnosed with IVL. In addition to FUO, 2 IVL patients also suffered from dyspnea and neurological disorders. Patients who had FUO with accompanying hematologic disorders, high LDH, negative BM study and no lymphadenopathy or hepatosplenomegaly had a significant tendency to have IVL by RSB (P = .03). FUO with hypoxemia was also identified as a significant indication for RSB (P = .02).

CONCLUSIONS

RSB is a reliable method for diagnosis of IVL, especially in patients with FUO and any 1 or more of the 4 following abnormalities: (1) hematologic abnormalities; (2) high serum LDH; (3) hypoxemia; and/or, (4) unusual neurological symptoms with co-existing hematologic abnormalities and without lymphadenopathy, hepatosplenomegaly or BM abnormality.

Anemia and Neutropenia in Copper-Deficient Patients: A Report of Two Cases and Literature Review

Copper deficiency is an uncommon, but treatable cause of hematologic abnormalities. We present and describe two interesting cases in this report. The first case was a 37-year-old man with history of short bowel syndrome and long-term total parenteral nutrition (TPN) presenting with pancytopenia and chronic symmetrical polyarthritis that resembled rheumatoid arthritis. The second case was a 64-year-old man with malabsorption from Cronkhite-Canada Syndrome (CCS) and history of subtotal gastrectomy presenting with macrocytic anemia and neutropenia. Bone marrow examination in both cases revealed cytoplasmic vacuolization of myeloid and erythroid precursors. After copper supplementation was initiated, hematological abnormalities and arthritis were significantly improved. We encourage clinicians to recognize early and identify copper deficiency in patients who have unexplained cytopenia, especially if there is history of upper gastrointestinal tract surgery, malabsorption, or long-term TPN.

Clinical Significance of Bone Marrow Involvement as Confirmed by Bone Marrow Aspiration vs. Bone Marrow Biopsy in Diffuse Large B-cell Lymphoma

BACKGROUND

In diffuse large B-cell lymphoma (DLBCL), bone marrow (BM) involvement confirmed by BM biopsy confers a poor prognosis. However, in clinical practice, there may be disagreement in results between BM biopsy and BM aspiration in determination of BM involvement. It is unknown which of BM biopsy or BM aspiration better correlates with clinical outcome.

OBJECTIVE

To evaluate clinical outcome of BM involvement as confirmed by BM aspiration vs. confirmation by BM biopsy in patients with DLBCL.

MATERIAL AND METHOD

Clinical data, treatment, and outcome of 126 DLBCL patients with available BM aspirate slides who attended the Hematology Clinic at Siriraj Hospital between January 1, 2007 and December 31, 2009 were reviewed. BM aspirate slides were revised and interpreted by hematologists.

RESULTS

BM involvement was found in 12.7% (16/126) by BM biopsy and 24.6% (31/126) by BM aspiration. Regarding BM biopsy results, rates of complete remission (CR) among patients with unequivocal involvement, equivocal involvement, and without involvement were 75.0%, 57.1%, and 77.7%, respectively (p = 0.464). Two-year overall survival (OS) rates among the three groups were not significantly different (p = 0.663). Regarding BM aspiration results, CR rates among patients with unequivocal involvement, equivocal involvement, and without involvement were 80.6%, 75.8%, and 72.7% (p = 0.755). Two-year OS rates among the three groups were not significantly different (p = 0.118). In multivariate analysis, BM involvement as determined by either BM biopsy or BM aspiration was not associated with CR rate or 2-year OS rates. However, the International Prognostic Index (PI) and use of rituximab were found to be signifcantly associated with CR rate and OS.

CONCLUSION

In patients with DLBCL, BM involvement confirmed by either BM biopsy or BM aspiration appears not to influence the rate of complete remission or 2-year overall survival.

Learning environment and resident achievement

OBJECTIVE

To evaluate the effect of program training atmosphere on the academic performance among internal medicine residents.

MATERIAL AND METHOD

Data of satisfaction survey among internal medicine residents in academic year 2012, conducted by the Royal College of Physicians of Thailand, were retrieved. Association between training environment rating scores in three major aspects (program training structure, faculty nurturance, and support system) and board certifying examination scores, were then assessed.

RESULTS

There were 12 training centers with 535 residents in that academic year. The mean satisfaction score for second-year residents was 77.1 ± 6.1, and the mean written examination score was 56.4 ± 4.6, with the modest correlation (r = 0.515, p = 0.087). For the third-year residents, the mean satisfaction score was 78.5 ± 6.5 and the mean clinical examination score was 71.1 ± 1.6, with no correlation (r = -0.004, p = 0.991). In the subgroup analysis in second-year residents, program training structure had strongest influence (r = 0.569, p = 0.053), as compared to faculty nurturance (r = 0.425, p = 0.169), andsupport system (r = 0.492, p = 0.104).

CONCLUSION

Perception of positive training environment, especially the program training structure, may influence the performance of internal medicine residents in term of knowledge achievement as determined by written examination score. However, it has no effect in terms of clinical skill accomplishments, as determined by clinical examination scores.

Therapeutic and survival outcomes following treatment of primary central nervous system lymphoma: a 12-year case study

AIM

The study primarily aimed to investigate therapeutic and survival outcomes following definitive treatment of primary central nervous system lymphoma (PCNSL).

METHODS

All patients with histopathologically proven PCNSL at our institute between 1998 and 2009 were recruited. The collated data included demographic, laboratory, neuroimaging, therapeutic and survival aspects.

RESULTS

Of 85 participants with the mean age of 52.8 years, 79 underwent neurosurgical procedures endeavoring for diagnosis or decompression. Fifty patients who received definitive treatment in our institute were evaluated for therapeutic response. In multivariate analysis, there was no variable associated with good response rate. Eastern Cooperative Oncology Group (ECOG) performance status >1 and elevated cerebrospinal fluid (CSF) protein level >45 mg/dL were significant prognostic factors of poor survival outcome as estimated by Cox regression analysis. The patients treated by high-dose methotrexate (HD-MTX)-based protocols with or without radiotherapy (RT) achieved significantly longer median survival than those treated by RT alone or other kinds of chemotherapy.

CONCLUSION

Neurosurgical procedure plays an important role for diagnosis of PCNSL. Surgical resection has no role in curative treatment and should be discarded unless considerable mass effect develops. HD-MTX should be considered as the primary chemotherapy for individuals agonizing from the disease.

High on-clopidogrel treatment platelet reactivity in Thai patients with chronic stable angina scheduled for percutaneous coronary intervention

OBJECTIVE

To determine the prevalence, clinical profile, and risk factors of high on-clopidogrel treatment platelet reactivity in Thai patients with chronic stable angina scheduled for percutaneous coronary intervention.

MATERIAL AND METHOD

The patients were prospectively recruited from the consecutive patients undergoing coronary angiography and planned for elective percutaneous coronary intervention (PCI). Ten ml of blood samples were cautiously drawn from the antecubital vein of the patients to determine the hemoglobin and platelet count. Platelet aggregation test was performed by light transmittance aggregometry using platelet-rich plasma. Platelets were stimulated with 5 microM adenosine diphosphate (ADP). Platelet aggregation was expressed as the maximal percent change in light transmittance from baseline. High on-clopidogrel treatment platelet reactivity was defined as post treatment maximal platelet aggregation > 46% with 5 micromol/l ADP used as agonist.

RESULTS

The present study consecutively enrolled two hundred four patients diagnosed with chronic stable angina planned for PCI. Seventy-nine patients demonstrated the high on-clopidogrel treatment platelet reactivity (38.7%). Among these patients, 48% were men with a mean age of 66 years. Diabetes mellitus and chronic kidney disease were detected in 34.2%. Original clopidogrel (Plavix) was prescribed in 72% of the patients and 28% received generic clopidogrel (Apolets). The prevalence of high on-clopidogrel treatment platelet reactivity increased in the older patients, patients with CKD and patients receiving angiotensin receptor blockers (ARB). However from multivariate analysis, none of the risk factors, including age, BMl, diabetes mellitus, smoking, CKD, ARB use, and type of clopidogrel (Plavix versus Apolets) had a statistically significant association with the high on-clopidogrel treatment platelet reactivity.

CONCLUSION

The prevalence of high on-clopidogrel treatment platelet reactivity in the present study was 38.7%. No significant association was demonstrated between age, BMI, diabetes mellitus, smoking, CKD, ARB use, type of clopidogrel, and high on-clopidogrel treatment platelet reactivity.

Aspirin resistance in Thai patients with chronic stable angina

OBJECTIVE

To determine the prevalence, clinical profile and risk factors of aspirin resistance in Thai patients with chronic stable angina.

MATERIAL AND METHOD

The patients were prospectively recruited from the consecutive patients diagnosed chronic stable angina at Siriraj Hospital during March 2011 to February 2012. Ten milliliter of blood samples were cautiously drawn from the antecubital vein of the patients to determine the hemoglobin, platelet count and platelet aggregation test performed by light transmittance aggregometry using platelet-rich plasma. Platelets were stimulated with 0.5 mg/ml of arachidonic acid and 10 mM adenosine diphosphate. Platelet aggregation was expressed as the maximal percent change in light transmittance from baseline. Aspirin resistance was defined as the mean platelet aggregation of > or = 70% with 10 mM ADP and the mean platelet aggregation of > or = 20% with 0.5 mg/ml of arachidonic acid.

RESULTS

One-hundred and fifty seven patients diagnosed chronic stable angina were enrolled in the present study. There were 34 patients (21.6%) demonstrating aspirin resistance. The clinical characteristic of these patients included male 58.8% with mean age of 66 years, body mass index 27.5 kg/m2, diabetes mellitus 52.9%, smoking 8.8%, hypercholesterolemia 70.6% and proton pump inhibitor use 23.5%. Multivariate analysis demonstrated none of the risk factors including age, female, body mass index, diabetes mellitus, hypercholesterolemia, smoking and proton pump inhibitor (PPI) use had a statistically significant association with aspirin resistance.

CONCLUSION

Our study demonstrated that the prevalence of aspirin resistance in Thai patients with chronic stable angina was 21.6%. No significant association was demonstrated between age, female, body mass index, diabetes mellitus, hypercholesterolemia, smoking, proton pump inhibitor (PPI) use and aspirin resistance.

Pulmonary lipiodol embolism after transcatheter arterial chemoembolization for hepatocellular carcinoma: a case report and literature review

Acute pulmonary lipiodol embolism is a rare but possibly fatal complication of transcatheter arterial chemoembolization (TACE). The authors report a 63-years-old woman with unresectable large (7.4 x 7.9 cm) hepatocellular carcinoma (HCC) who had been diagnosed pulmonary lipiodol embolism after the first TACE. Intraoperative angiography did not show the communication between pulmonary circulation and tumor feeding artery. After lipiodol injection, she developed oxyhemoglobin desaturation immediately and chest computed tomography (CT) angiography showed lipiodol embolism at basal segments of both lower lobes. She also developed fever after TACE without any evidence of infection. Oxyhemoglobin desaturation had improved to baseline spontaneously within 7 days. Fever persisted for 16 days. Two weeks after TACE, follow-up CT of liver revealed the absence of almost lipiodol granule in lungs. The patient did not receive TACE again because of pulmonary metastasis. In this article we reviewed the cases of pulmonary lipiodol embolism that had been reported in the literature including clinical risk factors, possible mechanisms and the pathophysiology of this complication.

The efficacy of 3-mg warfarin initiating dose in adult Thai patients, who required long-term anticoagulant therapy

BACKGROUND

Warfarin anticoagulation is the standard treatment for patients with thromboembolic diseases. Prior studies recommended commencing warfarin with the initial doses between 5 mg and 10 mg for the first 1 or 2 days. However, lower warfarin loading dose is advised for the elderly and patients with co-morbid diseases. Moreover, warfarin requirement is also affected by several genetic factors, which differ among various ethnic populations. Currently, the optimal initiating dose of warfarin in Thai patients is unknown. However, based on the observation of the clinical practice at Siriraj hospital, a lower starting dose (3 mg/day) of warfarin was commonly given to patients who required long-term anticoagulant therapy.

OBJECTIVE

To investigate the efficacy and safety of 3-mg warfarin initiating dose.

MATERIAL AND METHOD

A retrospective study of inpatients who received warfarin 3 mg/day for the first two days of oral anticoagulation therapy with the target INR of 2.0-3.0 at Siriraj hospital from January 2004-December 2007 was performed. The efficacy of 3-mg warfarin loading dose was determined by assessing the proportion of patients who achieved the target INR of 2.0-3.0 between day 3 and day 5 of warfarin treatment.

RESULTS

Total of 164 patients was included in the study. Eighty-six patients (52.4%) were males. The mean age was 55.1 + 16.8 years (range 16-88 years). The mean body weight and serum albumin were 61.5 +/- 12.2 kg and 3.7 +/- 0.7 g/dl, respectively. Prosthetic heart valve replacement was the most common indication for warfarin anticoagulation therapy (36%), followed by deep vein thrombosis (32.3%). The mean cumulative weekly dose of warfarin was 22.3 +/- 5.8 mg. The median time to therapeutic INR (2.0-3.0) was 6 days. Forty-seven patients (29%) achieved therapeutic INR between day 3 and day 5 of warfarin treatment. Time to therapeutic INR was not affected by age, gender, body weight, serum albumin, or concomitant medication use. Interestingly, patients who received warfarin due to prosthetic heart valve replacement were more likely to achieve therapeutic INR between day 3 and day 5 when compared to those with other indications with adjusted OR 16.25 (95% CI 5.13-51.44, p < 0.001). Bleeding complication was rare (0.6%) and was not associated with excessive anticoagulation.

CONCLUSION

3-mg warfarin initiating dose appeared to be safe in adult Thai patients. However, the efficacy of 3-mg starting dose as determined by the proportion of patients who achieved the target INR between day 3 and day 5 of warfarin treatment was relatively less efficient when compared with that previously reported with a 5-mg loading dose. Further randomized, prospective study is required to examine the efficacy of 3-mg versus higher warfarin starting dose in Thai patients.

Inadvertent intrathecal vincristine administration: report of a fatal case despite cerebrospinal fluid lavage and a review of the literature

Accidental intrathecal vincristine administration results in progressive ascending radiculomyeloencephalopathy usually leading to fatal outcome. No specific therapy for intrathecal vincristine toxicity has been reported. We report a 63-year-old man with diffuse large B-cell lymphoma at the right testis who inadvertently received intrathecal vincristine. Direct CSF aspiration and irrigation was done 30 minutes after the incident. Ventriculostomy and lumbar drain was placed. Intrathecal irrigation was started at 6.5 hours using FFP-containing lactate solution and continued for 11 days. In addition, antineurotoxic and neuroprotective agents were given. His neurological symptom deteriorated slowly and he died on day 12. Among 16 reported cases undergoing lumbar drainage and/or irrigation, 56.3% can survive 30 days or more and 37.5% had survive more than 6 months. Immediate CSF drainage and early irrigation is related to good outcome (prolonged survival with no encephalopathy). In our case, his poor outcome might be due to the delayed starting of irrigation. In conclusion, the appropriate and effective management of this complication is unknown. However, emergency cerebrospinal fluid drainage and irrigation remains the principal of management.

Incidence and risk factors of bone marrow involvement by non-Hodgkin lymphoma

BACKGROUND

Since trephine bone marrow biopsy is an invasive procedure, the identification of a subgroup of patients with Non-Hodgkin lymphoma (NHL) who have a minimal risk of bone marrow involvement would be helpful. This study is aimed to determine the incidence of bone marrow involvement (BMI) by NHL and the predictors of no BMI to not only avoid this invasive procedure but also decrease the cost of investigation.

MATERIAL AND METHOD

Data from 320 patients with NHL at division of hematology between January 2008 and June 2009 were reviewed and analyzed.

RESULTS

The cell types of NHL were classified as B-cell in 283 patients (88.4%), T-cell in 37 patients (11.6%) and incidence of BMI is 24.4% and 18.9% in B- and T-cell, respectively. Factors significantly associated with BMI in univariate analysis were the hepatic and splenic involvement (p = 0.03 and < 0.01, respectively), significant weight loss (p = 0.02), presence of lymphadenopathy (LN) below diaphragm (p = 0.02), anemia (p = 0.001), low percent of blood neutrophil (p < 0.001), high percent of blood lymphocyte (p < 0.001), low absolute neutrophil count (p = 0.002), high absolute lymphocyte count (p = 0.045), low platelet count (p < 0.001), high LDH (p = 0.026), and high alkaline phosphatase (p = 0.020). On the multivariate analysis, factors associated with BMI included LN below diaphragm, anemia, low percent of blood neutrophil and low platelet count. Excluding Burkitt lymphoma and mantle cell lymphoma, NHL patients with no LN below diaphragm, no hepatic & splenic involvement, no significant weight loss, hemoglobin (Hb) >11 g/dL and platelet > 150,000/uL had BMI in 3/78 (3.8%).

CONCLUSION

The incidence of bone marrow involvement in NHL is 23.8%. Excluding Burkitt lymphoma and mantle cell lymphoma, NHL patients with no LN below diaphragm, no hepatic & splenic involvement, no significant weight loss, Hb > 11 g/dL and platelet > 150,000/uL had low risk of BMI.

Can we predict final outcome of internal medicine residents with in-training evaluation

OBJECTIVE

To assess the predictive value of in-training evaluation for determining future success in the internal medicine board certifying examination.

MATERIAL AND METHOD

Ninety-seven internal medicine residents from Faculty of Medicine Siriraj Hospital who undertake the Thai Board examination during the academic year 2006-2008 were enrolled. Correlation between the scores during internal medicine rotation and final scores in board examination were then examined.

RESULTS

Significant positive linear correlation was found between scores from both written and clinical parts of board certifying examination and scores from the first-year summative written and clinical examinations and also the second-year formative written examination (r = 0.43-0.68, p < 0.001). Monthly evaluation by attending staffs was less well correlated (r = 0.29-0.36) and the evaluation by nurses or medical students demonstrated inverse relationship (r = -0.2, p = 0.27 and r = -0.13, p = 0.48).

CONCLUSION

Some methods of in-training evaluation can predict successful outcome of board certifying examination. Multisource assessments cannot well extrapolate some aspects of professional competences and qualities.

Progressive multifocal cerebral infarction from intravascular large B cell lymphoma presenting in a man: a case report

Introduction

Intravascular lymphoma is rare, and may present as ischemic stroke. Diagnosis is difficult due to the non-specific presentation and lack of lymphadenopathy, thus leading to frequent instances of autopsy-proven diagnosis. To the best of our knowledge, this is the first report of progressive stroke from intravascular lymphoma diagnosed antemortem by random skin biopsy.

Case presentation

A 42-year-old Thai man presented to our hospital with progressive multifocal cerebral infarction. Despite taking aspirin (300 mg/day), his neurological symptoms worsened. During admission, he developed an unexplained fever and hypoxemia. Magnetic resonance angiography clearly showed patency of all cerebral arteries including the internal carotid and vertebrobasilar arteries. Echocardiography, an antiphospholipid antibody test, cerebrospinal fluid cytology and a bone marrow study were normal. Other laboratory test results showed an elevated lactate dehydrogenase level, nephrotic range proteinuria (3.91 g/day), hypoalbuminemia (1.9 g/dL), a very low high-density lipoprotein level (7 mg/dL) and hypertriglyceridemia (353 mg/dL). Because of suspected vasculitis, pulse methylprednisolone was given with transiently minimal improvement. A random skin biopsy from both thighs revealed intravascular large B cell lymphoma. Chemotherapy was not given due to our patient having ventilator associated pneumonia. He died 10 days after the definite diagnosis was established.

Conclusion

One etiology of stroke is intravascular lymphoma, in which random skin biopsy can be helpful for antemortem diagnosis.

The association of prothrombin A19911G polymorphism with plasma prothrombin activity and venous thrombosis: results of the MEGA study, a large population-based case-control study

BACKGROUND

Prothrombin (FII) G20210A mutation and elevated plasma prothrombin activity are known risk factors for venous thrombosis. The risk of venous thrombosis among 19911G carriers of the prothrombin A19911G polymorphism has not been extensively investigated.

OBJECTIVES AND METHODS

We assessed prothrombin activity, FIIG20210A, and FIIA19911G polymorphisms in a large population-based case-control study, the Multiple Environmental and Genetic Assessment (MEGA) study of risk factors for venous thrombosis. Four thousand three hundred and sixty-five consecutive patients with a first episode of deep vein thrombosis of the leg or pulmonary embolism were included. The control group (n = 4779) consisted of partners of patients or persons gathered using a random-digit dialing method. We studied the effect of FIIA19911G polymorphism on prothrombin activity and thrombosis risk, also in combination with factor V Leiden.

RESULTS

Among FII20210-GG control subjects, FII19911-GG carriers had 7.1% [95% confidence interval (CI): 5.7-8.5] higher mean prothrombin activity than FII19911-AA carriers and the risk for GG carriers was 1.43-fold increased compared to AA carriers [odds ratio (OR) 1.43; 95% CI: 1.27-1.61]. Among FII20210-GA control carriers, the mean prothrombin activity in both FII19911-AA and -AG carriers was nearly equivalent [131.7% and 133.4%; mean difference (95% CI) = 1.7% (-7.2-10.7)]. Because of genetic linkage, FII19911-GG carriers were very rare on a FII20210-GA background, as only one FII20210A carrier had FII19911-GG. In FII20210-GA carriers, the OR increased from 3.05 (95% CI: 2.17-4.27) in subjects with FII19911-AA to 3.33 (2.28-4.85) in subjects with FII19911-AG, compared to those with FII20210-GG and FII19911-AA.

CONCLUSIONS

The FIIA19911G polymorphism is associated with mildly elevated prothrombin activity and is a risk factor for venous thrombosis.

Resistance to hepcidin is conferred by hemochromatosis-associated mutations of ferroportin

Ferroportin (FPN) mediates iron export from cells; FPN mutations are associated with the iron overloading disorder hemochromatosis. Previously, we found that the A77D, V162del, and G490D mutations inhibited FPN activity, but that other disease-associated FPN variants retained full iron export capability. The peptide hormone hepcidin inhibits FPN as part of a homeostatic negative feedback loop. We measured surface expression and function of wild-type FPN and fully active FPN mutants in the presence of hepcidin. We found that the Y64N and C326Y mutants of FPN are completely resistant to hepcidin inhibition and that N144D and N144H are partially resistant. Hemochromatosis-associated FPN mutations, therefore, either reduce iron export ability or produce an FPN variant that is insensitive to hepcidin. The former mutation type is associated with Kupffer-cell iron deposition and normal transferrin saturation in vivo, whereas patients with the latter category of FPN mutation have high transferrin saturation and tend to deposit iron throughout the liver parenchyma. FPN-linked hemochromatosis may have a variable pathogenesis depending on the causative FPN mutant.

In vitro functional analysis of human ferroportin (FPN) and hemochromatosis-associated FPN mutations

Type IV hemochromatosis is associated with dominant mutations in the SLC40A1 gene encoding ferroportin (FPN). Known as the "ferroportin disease," this condition is typically characterized by high serum ferritin, reduced transferrin saturation, and macrophage iron loading. Previously FPN expression in vitro has been shown to cause iron deficiency in human cell lines and mediate iron export from Xenopus oocytes. We confirm these findings by showing that expression of human FPN in a human cell line results in an iron deficiency because of a 3-fold increased export of iron. We show that FPN mutations A77D, V162delta, and G490D that are associated with a typical pattern of disease in vivo cause a loss of iron export function in vitro but do not physically or functionally impede wild-type FPN. These mutants may, therefore, lead to disease by haploinsufficiency. By contrast the variants Y64N, N144D, N144H, Q248H, and C326Y, which can be associated with greater transferrin saturation and more prominent iron deposition in liver parenchyma in vivo, retained iron export function in vitro. Because FPN is a target for negative feedback in iron homeostasis, we postulate that the latter group of mutants may resist inhibition, resulting in a permanently "turned on" iron exporter.

National survey of patients with hemophilia and other congenital bleeding disorders in Thailand

A national survey of patients with hemophilia and other congenital bleeding disorders in Thailand was conducted in the years 2000 to 2002. Questionnaires were sent to physicians working at hospitals throughout the country. Although the overall response rate to the questionnaires was 19%, the two highest rates of 80% and 73.7% were found at university and regional hospitals, respectively, where most of the patients received their diagnosis and treatment. A total of 1,450 patients comprised of hemophilia 1,325 cases, von Willebrand disease, 69 cases, congenital factor VII deficiency, 15 cases, hereditary platelet dysfunction, 22 cases, and undefined causes of congenital bleeding disorders, 19 cases. Most were pediatric patients <15 years of age. Treatment was mainly given on demand for a bleeding episode, while only 8.6% received additional home treatment for early bleeding episodes. Replacement therapy primarily relied on fresh frozen plasma, cryoprecipitate and cryo-removed plasma. Factor concentrate was seldom used because of the high price. As a result, hemophilia care services in Thailand should be strengthened by providing comprehensive education for medical personnel, making available simple laboratory kits to determine hemophilia A and B, ensuring an adequate supply of blood components and affordable factor concentrate, and establishing home care treatment.