[Retrospective analysis of clinical characteristics of patients with metabolic-associated fatty liver disease at high and low altitude areas]

Objective: To explore differences in clinical characteristics and hemoglobin levels between different age groups in patients with metabolic-associated fatty liver disease (MAFLD) at high and low altitude areas, so as to provide a basis for further research on the effect of chronic hypoxia on MAFLD. Methods: Liver function indexes, non-invasive fibrosis indexes, metabolic indexes, and routine blood test of 1 458 (Xining area of Qinghai province) and 1 633 cases (Huzhou area, Zhejiang province) with MAFLD who underwent physical examination were retrospectively analyzed. The total population of the two places were compared and analyzed with the hemoglobin reference limit of 180 g/L. The population of Xining was divided into high and low hemoglobin groups for comparative analysis. The population of the two places was divided into five groups according to age stratification (≤30 years old, 31-40 years old, 41-50 years old, 51-60 years old, ≥61 years old). After multivariate adjustment, the characteristics of high and low hemoglobin groups and MAFLD were compared between the two groups. Statistical analysis was performed with t-test or χ² test. Results: The detected indexes values observed were higher in Xining than Huzhou area population [fibrosis indexes (FIB4, 1.08±0.02 vs. 1.19±0.02), erythrocyte (5.14±0.13 vs. 5.30±0.13), hemoglobin (156.82±0.37 vs. 164.19± 0.39), alanine aminotransferase (ALT, 33.70±0.66 vs. 43.68±0.70), aspartate aminotransferase (AST, 24.34±0.28 vs. 29.23±0.30), γ-glutamyltransferase (42.40±1.02 vs. 51.82±1.53), alkaline phosphatase (77.92±0.56 vs. 84.63±0.85), triglyceride (TG, 2.07±0.04 vs. 2.74±0.05), uric acid (UA, 383.42±2.15 vs. 406.44±2.36)]. The detected indexes values observed were higher in Huzhou than Xining area population [platelet count (220.54±1.32 vs. 181.62±1.40), total cholesterol (TC, 5.10±0.02 vs. 5.04±0.03), fasting blood glucose (FBG, 5.67±0.04 vs. 5.29±0.04)]. The differences were statistically significant (P<0.01). Xining population UA and body mass index were increased in high hemoglobin group than low hemoglobin group, and the other parameters difference were not statistically significant. After the population in Xining was grouped by age, high and low FIB4, ALT, and AST and UA levels were detected in the age group of 31-40 and 51-60 years old, >61 years old, 31-40 years old, and the difference between hemoglobin groups were statistically significant (P<0.01). Conclusion: Patients with MAFLD are more likely to develop fibrosis, liver function impairment, metabolic disorders and so on under high-altitude hypoxic environment. Additionally, there is certain correlation with disease severity and age changes, suggesting that chronic hypoxia can accelerate MAFLD progression.

Investigation on detoxication effects of 2-hydroxypropyl-β-cyclodextrin over two halogenated aromatic DBPs 2,4,6-trichlorophenol and 2,4,6-tribromophenol binding with human serum albumin

The health effects of disinfection byproducts (DBPs) in drinking water drew great attention recently. Herein, by using in vitro (fluorescence quenching, UV absorbance, circular dichroism) and in silico (molecular docking) method, binding interactions of two halophenolic DBPs (2,4,6-trichlorophenol [TCP] and 2,4,6-tribromophenol [TBP]) with human serum albumin (HSA) and the influence of hydroxypropyl-beta-cyclodextrin (HPCD) on the interactions were investigated. TCP/TBP could form complexes with HSA mainly by hydrogen bonding, while changing its secondary structure, among which TBP showed more influential effect. Interestingly, the binding constants for halophenol-HSA complexes decreased obviously with the involvement of HPCD. Molecular docking results revealed that HPCD could include TCP/TBP into its cavity and change their original binding sites from subdomain IB to IIA, resulting in a more stable binding system. These findings are beneficial for understanding the toxicity of halophenols inside the human body and indicated that HPCD could be a promising detoxication agent for DBPs.

[The association of posterior tibial slope changes between joint gap contact force and the range of motion in Oxford mobile bearing unicompartmental knee arthroplasty]

Objective: To investigate the correlation between the change of posterior tibial slope (PTS) after unicompartmental knee arthroplasty (UKA) and the contact force at the end stage of knee flexion and extension, as well as the postoperative range of motion. Methods: The data of 38 cases (46 knees) of UKAs undertaken in China-Japan Friendship Hospital from June 2020 to June 2021 were analyzed in this study. A custom-designed force sensor was used to measure gap contact force in the medial gap of UKA. The correlations between each two of the three factors-the change of PTS (∆PTS), the gap contact force of full extension and deep flexion and the range of knee motion were analyzed. Results: Totally of 38 patients (46 knees) were enrolled, including 14 males and 24 females, aged (69.1±7.4) years, with an average follow-up of (11.2±3.7) months. The average gap contact force was (88.3±40.6)N, the adjusted contact force of the full extension gap was 81.7%±33.8%, while that of the deep flexion gap was 55.6%±31.0%. At the last follow-up, the fixed flexion degree[M(Q₁, Q₃)] was 0°(0°, 3°), which was significantly lower than the preoperative value of 0°(0°, 5°) (P<0.05); the postoperative max flexion degree was 115.9°±16.4°, it was increased when compared with the preoperative value of 112.0°±16.8° (P<0.05); and the postoperative PTS was 8.3°±2.7°, and there was no significant difference with the preoperative value (8.6°±2.1°,P>0.05). There was a positive correlation between ∆PTS and both the contact force of full extension gap and the fixed flexion degree (r=0.334 and 0.317, P<0.05). Besides, there was a negative correlation between ∆PTS and the contact force of the deep flexion gap (r=-0.397, P<0.05). However, the correlations between these two factors and the max flexion degree were not significant (P>0.05). Conclusions: The reduction of PTS in UKA would reduce the contact force of the full extension gap, as well as the postoperative fixed flexion deformity. Besides, it could increase the contact force of the deep flexion gap, but would not influence the max flexion degree of the knee postoperatively.

[Pancreas multidisciplinary team optimizes the diagnosis and treatment of pancreas-related diseases and improves the prognosis of pancreatic cancer patients]

Objectives: To evaluate the role of pancreas multidisciplinary team(MDT) clinic in the diagnosis of pancreatic diseases,patient compliance with MDT advice,and the impact of MDT on the postoperative survival of patients with pancreatic cancer. Methods: The study included 927 patients(554 males,373 females,aged (58.1±13.3)years (range: 15 to 89 years)) that had visited the pancreas MDT clinic of Zhongshan Hospital from May 2015 to December 2021,and 677 patients(396 males, 281 females, aged (63.6±8.9)years(range: 32 to 95 years)) who underwent radical surgery and with pathologically confirmed pancreatic adenocarcinoma from January 2012 to December 2020,of whom 79 patients had attended the pancreas MDT. The clinical and pathological data were collected and analyzed retrospectively. Diseases were classified in accordance with 2010 WHO classification of tumors of the digestive system and usual clinical practices. The Kaplan-Meier method was used for drawing the survival curve and calculating the survival rate. The univariate analysis was done by Log-rank test and the multivariate analysis was done by COX proportional hazards model. Survival rates were compared using χ2 test. Results: Among the 927 patients that had visited the MDT clinic,233 patients(25.1%) were referred due to undetermined diagnosis. A direct diagnosis was made in 109 cases (46.8%,109/233) by the MDT clinic, of which 98 were consistent with the final diagnosis,resulting in an accuracy of 89.9%(98/109). The direct diagnosis rate in the recent years(36.6%(41/112),from June 2019 to December 2021) decreased compared to that in the previous years(56.2%(68/121),from May 2015 to May 2019),yet the accuracy in the recent years(90.2%,37/41) was basically the same as before (89.7%,61/68). The rate of compliance of the entire cohort was 71.5%(663/927), with the compliance rate in the recent two and a half years(81.4%,338/415) remarkably higher than that in the previous four years(63.4%,325/512). Patients with pancreatic cancer that attended the MDT exhibited a trend toward longer median postoperative survival than patients that did not attend the MDT,but the difference was not statistically significant(35.2 months vs.30.2 months,P>0.05). The 1-year and 3-year survival rates of patients that attended the MDT were significanly higher than patients that did not attend the MDT(88.6% vs. 78.4%,P<0.05;32.9% vs. 21.9%,P<0.05,respectively),but the 5-year survival rate was not statistically different(7.6% vs. 4.8%,P>0.05). Conclusions: The pancreas MDT clinic is an accurate and convenient way to diagnose intractable pancreatic diseases,and in the recent years the patients' compliance rate with MDT advice has increased. Pancreatic cancer patients that have attended the MDT have higher 1-year and 3-year postoperative survival rates,but the long-term survival benefits of MDT still needs to be proved by clinical studies on a larger scale.

A systematic review of the nutritional status of adults experiencing homelessness

OBJECTIVES

To identify, appraise, and describe studies focussing on the nutritional characteristics of people experiencing homelessness (PEH).

STUDY DESIGN

Systematic (narrative) review.

METHODS

We identified full-text studies of any design and in the English language of adults (≥18 years) fulfilling the European Typology criteria for homelessness, based in community or hospital settings, and which report nutritional measures. Five electronic databases, 13 grey literature sources, reference lists, and forward citations were searched. Data on study characteristics and nutrition measures were collected and synthesised narratively. Risk of bias was assessed using relevant checklists for each study type.

RESULTS

A total of 1130 studies were identified and retrieved. After screening, six studies were included for review: three cross-sectional studies; two case-control studies; and one randomised control trial, involving a total of 1561 participants from various settings including shelters, drop-in centres, hospitals, and hostels. All included studies were from high-income countries. Studies reported a range of nutrition measures including anthropometry (e.g., body mass index (BMI)), serum micronutrients and biomarkers, and dietary intake. Between 33.3% and 68.3% of participants were overweight or obese; 3.5%-17% were underweight; and low blood levels of iron, folate, vitamins C, D, and B12, and haemoglobin were prevalent. PEH consumed high amounts of dietary fats and alcohol, and low amounts of fruits and vegetables compared with national guidelines and housed individuals. There was moderate to high risk of selection and measurement bias and confounding in included studies.

CONCLUSIONS

A majority of PEH are within unhealthy BMI ranges and are deficient in serum micronutrients and nutritional biomarkers. Studies using large data sets that examine multiple aspects of nutrition are needed to describe the nutritional characteristics of PEH.

REGISTRATION

This systematic review is based on a prespecified protocol registered with the International Prospective Register of Systematic Reviews (PROSPERO CRD42021218900).

AB1442 A PREDICTIVE MODEL OF CATASTROPHIC ANTIPHOSPHOLIPID SYNDROME: A RETROSPECTIVE COHORT STUDY

Background

Catastrophic antiphospholipid syndrome (CAPS) is a life-threatening form of antiphospholipid syndrome (APS), with rarely occurrence but high mortality. Current classification diagnosis criteria require more than 3 organs involvement in 1-week time and pathological evidence in patient with persistent positive antiphospholipid antibodies (aPL), which could result the delaying diagnosis and treatment. A predictive model could help identify CAPS patients earlier and initiate early intervention.

Objectives

To develop a predictive model of CAPS in APS patients in a single-center prospective APS cohort.

Methods

Data of consecutive APS patients referred into Peking Union Medical College Hospital from May 2013 to October 2021 was collected. A binary logistic regression method was used to identify predictors of CAPS, coefficient B was assigned with score value in the development of prediction model, and risk-stratification was based on the calculated score using the predictive model. The performance of the model was assessed by Nagelkerke’s R2, Hosmer-Lemeshow test, Omnibus test, and area under the receiver operating characteristic curve (AUC).

Results

A total of 27 CAPS (11.9%) occurred in 226 APS patients. CAPS were more likely to occur in male secondary APS patients with history of arterial thrombosis. Precipitating factors (OR 108.961, 95% CI 23.299 to 509.572), thrombocytopenia (OR 14.765, 95% CI 3.088 to 70.612) and elevated serum creatine (OR 5.339, 95% CI 1.301 to 21.907) were selected by the binary logistic regression. The scores of precipitating factors, thrombocytopenia and elevated serum creatine were 5, 3 and 2. The risk scores were divided into high-risk (7-10) and low-risk (0-6), the risk for CAPS were 73.3% and 2.6%, with sensitivity of 81.5% and specificity of 96%. The Nagelkerke’s R2 (0.696), the Hosmer-Lemeshow test (χ2 =2.192, df=4, p=0.701) and the Omnibus test (χ2 =101.307, df=3, p=0.000) indicated the logistic regression model has a good fit. The AUC was 0.969 (95% CI 0.947 to 0.991, SE=0.011, p=0.000) indicated the model has good discrimination.

Conclusion

A predictive model of CAPS was developed with precipitating factors, thrombocytopenia, and elevated serum creatine. This model helps physicians identify CAPS in high-risk patients, could achieve early intervention and improve prognosis.

Table 1.

Characteristics and predicting factors of CAPS in PUMCH-APS cohort

CAPS（N=27）Non-CAPS（N=199）pOdds ratiopCoefficient ΒScoreGender（M）14(51.9)64(32.2)0.043Age (y)36.3±15.236.2±12.50.975Disease duration (m)49.7±77.753.9±72.30.777Secondary APS14(51.9)52(26.1)0.006APS diagnosisVenous thrombosis17(63.0)106(53.3)0.342Arterial thrombosis22(81.5)79(39.7)0.000Pregnancy morbidity5(18.5)68(34.2)0.103LA22(81.5)155(77.9)0.671aCL21(77.8)123(61.8)0.105a-β2GP123(85.2)155(77.9)0.384Precipitating factors24(88.9)19(9.5)0.000108.961(23.299-509.572)0.0004.6915WBC(×109/L)9.0±6.36.6±2.90.067HGB(g/L)82.7±20.4130±23.80.000Hemolytic anemia15(55.6)20(10.1)0.000PLT(×109/L)61.1±67.1132±84.00.000Thrombocytopenia24(88.9)80(40.2)0.00014.765(3.088-70.612)0.0012.6923Cr(μmol/L)224.5±225.874.4±28.40.002Elevated Cr15(55.6)34(17.1)0.0005.339(1.301-21.07)0.0201.6752LDH(U/L)476.4±227.0226.9±92.30.000 Elevated LDH25(92.6)54(27.1)0.000Proteinuria18(66.7)28(14.1)0.000Hematuria15(55.6)20(10.1)0.000Figure 1.

(A). Receiver Operating Characteristic (ROC) curve of the predictive model. Area under the receiver operating characteristic curve (AUC) was 0.969, the cut-off value of 7 were with sensitivity of 81.5% and specificity of 96%. (B). Calibration curve in internal validation.

Disclosure of Interests

None declared

OP0145 VALIDATION OF 3 PREDICTION MODELS FOR THROMBOSIS IN ANTIPHOSPHOLIPID SYNDROME PATIENTS BASED ON A PROSPECTIVE COHORT

Background

Antiphospholipid syndrome (APS) is a rare and complicated acquired autoimmune thrombophilia characterized by arterial/venous thrombosis and/or recurrent pregnancy loss. Thrombosis is the first cause of death of APS patients. However, there has been no generally acknowledged model to predict thrombosis. Only adjusted global APS score (aGAPSS) was developed for prediction but based on a cross-sectional study1. Additionally, the predictive ability of Padua score and Caprini score has not been validated in APS patients.

Objectives

Aim to validate the ability of aGAPSS, Padua score and Caprini score to predict thrombosis in APS patients basing on a prospective cohort.

Methods

Consecutive APS patients who fulfilled the 2006 Sydney Revised Classification Criteria for APS, referred to Peking Union Medical College Hospital were included. Clinical data, aGAPSS, Padua score, and Caprini score at the time of diagnosis were collected. Patients with less than 1-year follow-up were excluded. Harrell c-index and calibration curve were used to validate the prediction models.

Results

A total of 302 patients were enrolled in this study. The mean age was 32±12 years old, and 202 (66.9%) were female (Table 1). Patients were followed up for a median of 36 months. During the follow-up period, there were 62 thrombotic events, with 40 (13.25%) venous and 22 (7.28%) arterial thrombosis. The 1-, 3-, and 5-year thrombosis risks were 8.9%, 16.9%, and 21.3% respectively (Figure 1A). The Harrell c-indexes for predicting thrombosis of aGAPSS, Padua score, and Caprini score were 0.56 (95% confidence interval [CI], 0.52-0.60), 0.58 (95% CI, 0.54-0.62), and 0.61 (95%CI, 0.57-0.65) respectively. The model predicting venous thrombosis with the best discrimination was Padua score whose Harrell c-index was 0.64 (95% CI, 0.60-0.68), and the model predicting arterial thrombosis with the best discrimination was Caprini score whose Harrell c-index was 0.62 (95%CI, 0.56-0.68). The calibration curves illustrated that the calibration for predicting thrombosis within 3 years after diagnosis of all the 3 models was poor (Figure 1B-D).

Table 1.

Demographic characteristics and clinical manifestations at baseline

N=302N=302Age, mean±SD32±12Clinical manifestationsFemale, n (%)202 (66.9)Venous thrombosis, n (%)156 (51.7)Disease duration (months), median (Q1, Q3)11.50 (3.00, 44.00)Deep venous thrombosis, n (%)112 (37.1)Secondary to SLE, n (%)73 (24.2)Pulmonary embolism, n (%)70 (23.2)Smoking history, n (%)63 (20.9)Visceral venous thrombosis, n (%)12 (4.0)Hypertension, n (%)59 (19.5)Cranial venous sinus thrombosis, n (%)13 (4.3)Hyperlipidemia, n (%)151 (50.0)Arterial thrombosis, n (%)113 (37.4)BMI, mean±SD23.96±3.89Stroke/TIA, n (%)62 (20.5)LA positive, n (%)241 (79.8)Myocardial infarction, n (%)14 (4.6)aCL positive, n (%)208 (68.9)Arterial thrombosis of lower extremities, n (%)22 (7.3)aβ2GPI positive, n (%)242 (80.1)Visceral arterial thrombosis, n (%)18 (6.0)Triple aPL positive, n (%)165 (54.6)Thrombocytopenia, n (%)118 (39.1)Obstetric manifestations, n (%)N=202Valvular lesions, n (%)24 (7.9)Pregnancy morbidity103 (51.0)Early miscarriages (<10 weeks)13 (6.4)Fetal death (>= 10 weeks)68 (33.7)Preeclampsia, eclampsia and placental dysfunction36 (17.8)Figure 1.

The Kaplan-Meier curve and the calibration curve of 3 prediction models within 3 years after diagnosis. A: The Kaplan-Meier curve of venous, arterial and both venous and arterial thrombosis. B: The calibration curves for venous thrombosis. C: The calibration curves for arterial thrombosis. D: The calibration curves for both venous and arterial thrombosis.

Conclusion

The ability of aGAPSS, Padua score and Caprini score to predict thrombosis in APS patients is relatively poor. Construction of a new prediction model specifically for APS patients is required to help with early prevention and treatment.

References

[1]Sciascia, S., et al., GAPSS: the Global Anti-Phospholipid Syndrome Score. Rheumatology (Oxford), 2013. 52(8): p. 1397-403.

Disclosure of Interests

None declared

[Impact of nonsteroidal anti-inflammatory drugs on efficacy of anti-PD-1 therapy for primary liver cancer]

OBJECTIVE

To assess the impact of nonsteroidal anti-inflammatory drugs (NSAIDs) on clinical outcomes of patients receiving anti-PD-1 immunotherapy for hepatocellular carcinoma.

METHODS

We conducted a retrospective study among 215 patients with primary liver cancer receiving immunotherapy between June, 2018 and October, 2020. The patients with balanced baseline characteristics were selected based on propensity matching scores, and among them 33 patients who used NSAIDs were matched at the ratio of 1∶3 with 78 patients who did not use NSAIDs. We compared the overall survival (OS), progression-free survival (PFS), and disease control rate (DCR) between the two groups.

RESULTS

There was no significant difference in OS between the patients using NSAIDs (29.7%) and those who did not use NSAIDs (70.2%). Univariate and multivariate analyses did not show an a correlation of NSAIDs use with DCR (univariate analysis: OR=0.602, 95% CI: 0.299-1.213, P=0.156; multivariate analysis: OR=0.693, 95% CI: 0.330-1.458, P=0.334), PFS (univariate analysis: HR=1.230, 95% CI: 0.789-1.916, P=0.361; multivariate analysis: HR=1.151, 95% CI: 0.732-1.810, P=9.544), or OS (univariate analysis: HR=0.552, 95% CI: 0.208-1.463, P=0.232; multivariate analysis: HR=1.085, 95% CI: 0.685-1.717, P=0.729).

CONCLUSION

Our results show no favorable effect of NSAIDs on the efficacy of immunotherapy in patients with advanced primary liver cancer, but this finding still needs to be verified by future prospective studies of large cohorts.

Associations between alexithymia, parental rearing styles, and frequency of drug use in male methamphetamine dependence patients

BACKGROUND

Alexithymia, which is characterized by difficulty identifying and describing feelings, is a stable personality trait and it has been associated with early life experiences. Methamphetamine dependence patients with high level of alexithymia may be particularly vulnerable to engaging in more frequent methamphetamine use. Therefore, we aimed to evaluate whether alexithymia was associated with frequency of methamphetamine use. Additionally, the current study sought to examine early-life factors associated with the development of alexithymia, i.e., parental rearing styles.

METHOD

Participants were 108 non-injecting methamphetamine dependent patients from a male compulsory detoxification center. The level of alexithymia was assessed by Toronto Alexithymia Scale-20(TAS-20). In addition, we applied Egna Minneu av. Bardndosnauppforstran (EMBU) to assess the parental rearing styles, including the dimensions of warmth, rejection, punishment/strictness, overinvolvement, overprotection, and favoring.

RESULTS

The total score of TAS-20 was positively correlated with frequency of methamphetamine use (r = 0.26, p < 0.01). Specifically, except for externally oriented thinking, difficulty identifying feelings (r = 0.23, p < 0.05) and difficulty describing feelings (r = 0.25, p < 0.05) were positively correlated with frequency of methamphetamine use. Multiple linear regression showed that more maternal rejection (B = 0.59, p = 0.002), or less maternal warmth (B = -0.22, p = 0.004) was associated with higher levels of alexithymia. Ordinal logistic regression showed that for every 1 score increase in the total score of TAS-20, there was a 1.06 times risk of a one level increase in the level of methamphetamine use frequency (OR = 1.06, p = 0.01).

CONCLUSIONS

These results have major implications for understanding the role of alexithymia in craving and addiction, while providing a further and explicit entry point for addiction treatment. Moreover, more attention should be focused on parenting in relation to early experiences.

Effects of Plant Extracts on Dentin Bonding Strength: A Systematic Review and Meta-Analysis

Objective: To systematically review in vitro studies that evaluated the effects of plant extracts on dentin bonding strength.

Materials and Methods: Six electronic databases (PubMed, Embase, VIP, CNKI, Wanfang and The Cochrane Library) were searched from inception to September 2021 in accordance with the Preferred Reporting Items for Systematic Reviews (PRISMA). In vitro studies that compared the performance of dental adhesives with and without the plant extracts participation were included. The reference lists of the included studies were manually searched. Two researchers carried out study screening, data extraction and risk of bias assessment, independently and in duplicate. Meta-analysis was conducted using Review Manager 5.3.

Results: A total of 62 studies were selected for full-text analysis. 25 articles used the plant extracts as primers, while five added the plant extracts into adhesives. The meta-analysis included 14 articles of in vitro studies investigating the effects of different plant extract primers on dentin bonding strength of etch-and-rinse and self-etch adhesives, respectively. The global analysis showed statistically significant difference between dental adhesives with and without plant extract primers. It showed that the immediate bond strength of dental adhesives was improved with the application of plant extract primers.

Conclusion: The application of proanthocyanidin (PA) primers have positive effect on the in vitro immediate bonding strength of dental adhesives irrespective of etch-and-rinse or self-etch modes.

Enhanced removal of organoarsenic by chlorination: Kinetics, effect of humic acid, and adsorbable chlorinated organoarsenic

In this study, the effective removal of organoarsenic by the combined process of "chlorination + Fe(II)" was achieved. Chlorine could effectively degrade roxarsone (ROX) over pH from 5 to 10. The fitting results of acid-base protonation model proved that the degradation of ROX was mainly attributed to the reaction of HOCl and deprotonated ROX. The transformation of arsenic species conformed to the fitting results of two-channel kinetic model, in which 32.4% of ROX was oxidized to As(V) via electron transfer pathway (ii) and the rest was converted into monochloro-ROX via electrophilic substitution pathway (i). Humic acid inhibited the degradation of ROX due to the competitive consumption of chlorine and the restraint on the pathway ii. Subsequently, an enhanced removal of total arsenic achieved after chlorination, due to that the generating As(V) and monochloro-ROX were easier adsorbed compared with ROX, over 97.8% of total arsenic was removed by ferric (oxyhydr)oxides which in-situ formed from the oxidation of Fe(II). Additionally, toxicity studies indicated that the acute toxicity was significantly eliminated by adding Fe(II) after chlorination, likely due to the removal of As(V) and chlorinated products. Furthermore, organoarsenic was also effectively removed by the combined process of "chlorination + Fe(II)" in real water.