AHAmir Haddad

Amir Haddad

*This is an algorithmically generated author record based on publicly available information.

Current Organizations / Institutes

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Previous Organizations / Institutes

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Amir Haddad has a total of 38 co-authors. Here are the top co-authors by number of shared publications:

  • Arnon Dov Cohen

    Chief Physician's Office, Central Headquarters, Clalit Health Services, Tel Aviv, Israel; Siaal Research Center for Family Medicine and Primary Care, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheba, Israel

    4 shared publications
  • Devy Zisman

    Rheumatology Unit, Carmel Medical Center, Haifa, Israel; Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel

    4 shared publications
  • Devy Zisman

    Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3109601, Israel

    4 shared publications
  • Ilan Feldhamer

    Chief Physician's Office, Central Headquarters, Clalit Health Services, Tel Aviv, Israel

    4 shared publications
  • Tal Gazitt

    Rheumatology Unit, Carmel Medical Center, Haifa, Israel

    3 shared publications
  • Walid Saliba

    Department of Epidemiology, Clalit health services, Haifa, Israel; Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel

    3 shared publications

Latest Publications

  • Open Access

    Biologic switching in psoriatic arthritis: Insights from real-world data and key risk factors

    by Amir Haddad, Nili Stein, Ilan Feldhamer, Arnon Dov Cohen, Walid Saliba, Devy Zisman


  • Open Access

    Tofacitinib Regulates Endostatin via Effects on CD147 and Cathepsin S

    by Devy Zisman, Hala Sabtan, Maya M. Rahat, Elina Simanovich, Amir Haddad, Tal Gazitt, Joy Feld, Gleb Slobodin, Adi Kibari, Muna Elias, et al.

    Angiogenesis is critical for rheumatoid arthritis (RA) progression. The effects of tofacitinib, a JAK-STAT inhibitor used for RA treatment, on angiogenesis in RA are unclear. We, therefore, evaluated the levels of angiogenic factors in two systems of a human co-culture of fibroblast (HT1080) and monocytic (U937) cell lines treated with tofacitinib and in serum samples from RA patients before and after six months of tofacitinib treatment. Tofacitinib reduced CD147 levels, matrix metalloproteinase-9 (MMP-9) activity, and angiogenic potential but increased endostatin levels and secreted proteasome 20S activity. In vitro, tofacitinib did not change CD147 mRNA but increased miR-146a-5p expression and reduced STAT3 phosphorylation. We recently showed that CD147 regulates the ability of MMP-9 and secreted proteasome 20S to cleave collagen XVIIIA into endostatin. We show here that tofacitinib-enhanced endostatin levels are mediated by CD147, as CD147-siRNA or an anti-CD147 antibody blocked proteasome 20S activity. The correlation between CD147 and different disease severity scores supported this role. Lastly, tofacitinib reduced endostatin’ s degradation by inhibiting cathepsin S activity and recombinant cathepsin S reversed this in both systems. Thus, tofacitinib inhibits angiogenesis by reducing pro-angiogenic factors and enhancing the anti-angiogenic factor endostatin in a dual effect mediated partly through CD147 and partly through cathepsin S.


  • Open Access

    Epidemiological trends in psoriatic arthritis: a comprehensive population-based study

    by Amir Haddad, Perach Chen Elkayam, Nili Stein, Ilan Feldhamer, Arnon Dov Cohen, Walid Saliba, Devy Zisman

    Background: Psoriatic arthritis (PsA) is a chronic, potentially debilitating inflammatory arthritis often associated with psoriasis. Understanding the epidemiology of PsA across diverse populations can provide valuable insights into its global burden and the role of genetic and environmental factors. This study aimed to estimate PsA’s temporal trends, prevalence, and incidence, while assessing variations in age, gender, and ethnicity in Israel from 2016 to 2022. Methods: Data were sourced from the Clalit Health Services (CHS) database, covering over half of the Israeli population. Algorithm-based definitions for PsA and psoriasis cases were used. Demographic factors, including age, gender, socioeconomic status (SES), ethnicity, urban/rural residence, BMI, and smoking status, were analyzed. Standardized prevalence and incidence rates were calculated. Logistic regression analyses examined associations of sociodemographic variables with PsA. Results: In 2022, the prevalence of PsA was 0.221%, with an incidence rate of 13.54 per 100,000 population. This prevalence has tripled since 2006, reflecting a rising trend in PsA over time. Females exhibited a higher prevalence (1.15; 95%CI 1.09–1.21), and PsA was more common in Jewish individuals (1.58; 95%CI 1.45–1.71) those with higher SES (1.4; 95% CI 1.31, 1.5), and those with obesity (2.17; 95%CI 2.04–2.31). Conclusions: This comprehensive population-based study pointed to an increase prevalence of PsA, emphasizing the rising healthcare demands and economic burden faced by this patient population. Further research is essential to delve into the factors driving these trends.


  • Open Access

    The Risk of Herpes Zoster Events in Patients with Spondyloarthritis and the Effect of BNT162b2 mRNA COVID-19 Vaccine

    by Tal Gazitt, Noa Hayat, Nili Stein, Amir Haddad, Ilan Feldhamer, Arnon Dov Cohen, Walid Saliba, Devy Zisman

    The data on the risk of herpes zoster (HZ) in spondyloarthropathy (SpA) patients are sparse, especially regarding its association with the novel mRNA COVID-19 vaccines and immunosuppressants. We aimed to evaluate whether SpA diagnosis and/or immunosuppressant use affect HZ risk and the influence of mRNA COVID-19 vaccination. We assessed the association between SpA (psoriatic arthritis (PsA) and ankylosing spondylitis (AS)) diagnoses and HZ in a large population database with patients matched by age and sex to controls. We also assessed the association between the COVID-19 vaccine and new-onset HZ using two nested case–control studies, identifying all new HZ cases diagnosed from 1 January–31 December 2021 within the SpA and general population cohorts, matched randomly by sex, age and HZ index date to controls without HZ. Exposure to mRNA COVID-19 vaccination was ascertained in the 6 weeks prior to the index date both in cases and controls. In our results, the incidence rate of HZ was higher in PsA patients vs. the general population, at 1.03 vs. 0.64 per 100 person-years, respectively (adjusted HR = 1.55; 95%CI, 1.19–2.02). Within the SpA group, Jak-I treatment was associated with a higher risk of developing new-onset HZ (adjusted OR = 3.79; 1.15–12.5). Multivariable conditional logistic regression models we used showed no association between COVID-19 vaccination and new-onset HZ among the SpA patients (OR = 1.46; 0.68–3.14).

  • Open Access

    Development of Autoantibodies Following BNT162b2 mRNA COVID-19 Vaccination and Their Association with Disease Flares in Adult Patients with Autoimmune Inflammatory Rheumatic Diseases (AIIRD) and the General Population: Results of 1-Year Prospective Follow-Up Study

    by Tal Gazitt, Tali Eviatar, Jacqueline Shear, Roni Meidan, Victoria Furer, Joy Feld, Amir Haddad, Muna Elias, Nizar Hijazi, Nili Stein, et al.

    Development of autoantibodies following BNT162b2 mRNA COVID-19 vaccination and their association with disease flares in adult patients with autoimmune inflammatory rheumatic diseases (AIIRD) and the general population: results of 1-year prospective follow-up study. We conducted a prospective study aimed at investigating the incidence of appearance of autoantibodies (antinuclear, antiphospholipid, and rheumatoid factor) in the sera of 463 adult patients with AIIRD compared to 55 controls from the general population prior to, and following the second and third vaccine doses, and at 1-year of follow-up. Pre- and post-vaccination disease activity indices and the association of autoantibodies with rheumatic disease flares and new onset AIIRD were examined. Autoantibody development of any type in AIIRD patients vs. the controls was 4.0% (vs. 6.7%, p = 0.423) following two vaccine doses and 7.6% (vs. 0%, p = 0.152) after three doses. There was no significant difference in sex, age, or disease-type among individuals with and without autoantibody development, regardless of the immunosuppressant use. More patients developed autoantibodies following the third than the second vaccine dose (p = 0.004). Disease flares occurred in 5.8% and 7.2% of AIIRD patients following second and third vaccine doses, respectively, with autoantibody production increasing the risk of flares following the second (p = 0.002) and third (p = 0.004) vaccine doses. BNT162b2 vaccination resulted in the development of autoantibodies in a minority of AIIRD patients and controls. Autoantibody development was associated with disease flares in patients, but no new-onset autoimmunity was observed.


  • The Association of Psoriatic Arthritis With All-cause Mortality and Leading Causes of Death in Psoriatic Arthritis

    by Amir Haddad, Walid Saliba, Idit Lavi, Amin Batheesh, Samir Kasem, Tal Gazitt, Ilan Feldhamer, Arnon Dov Cohen, Devy Zisman

    Objective: To examine the association between psoriatic arthritis (PsA) and all-cause mortality from a large population-based database.Methods: Patients with PsA from the Clalit Health Services database were identified between 2003–2018 and matched to 4 controls by age, sex, ethnicity, and index date. Patient demographics, comorbidities, and treatments were extracted. Mortality data were obtained from the Israeli Notification of Death certificate. The proportionate mortality rate (PMR) of the leading causes of death was calculated and compared to that of the general population. Cox proportional hazard regression models were used to estimate the crude and the multivariate adjusted HR for the association between PsA and all-cause mortality and for factors associated with mortality within the PsA group.Results: There were 5275 patients with PsA and 21,011 controls included and followed for 7.2 ± 4.4 years. The mean age was 51.7 ± 15.4 years, and 53% were females. Among patients with PsA, 38.2% were on biologics. Four hundred seventy-one (8.9%) patients died in the PsA group compared to 1668 (7.9%) in the control group. The crude HR for the association of PsA and all-cause mortality was 1.16 (95% CI 1.04–1.29) and 1.02 (95% CI 0.90–1.15) on multivariate analysis. Malignancy was the leading cause of death (26%), followed by ischemic heart disease (15.8%); this is in keeping with the leading causes of death in the general population. Older age, male sex, lower socioeconomic status, increased BMI, increased Charlson comorbidity index scores, and history of psoriasis or hospitalization in 1 year prior to entry were positive predictors for mortality.Conclusion: No clinically relevant increase in mortality rate was observed in patients with PsA, and specific PMRs were similar to those of the general population.


  • Open Access

    Treatment persistence of biologics among patients with psoriatic arthritis

    by Amir Haddad, Tal Gazitt, Ilan Feldhamer, Joy Feld, Arnon Dov Cohen, Idit Lavi, Faten Tatour, Irena Bergman, Devy Zisman

    Background: Persistence of biologic therapy in psoriatic arthritis (PsA) patients is an important factor in individualized patient treatment planning and healthcare policy and guideline development. Objective: To estimate the persistence of biologic agents prescribed to PsA patients in a real-life setting as well as factors associated with improved biologic drug survival in these patients. Methods: Patients with PsA from a large healthcare provider database with at least two consecutive dispensed prescriptions of a biologic agent indicated for PsA from January 1, 2002, until December 31, 2018, were identified and followed until medication stop date or the end of observation period. Patients were considered non-persistent whenever a permissible lag time of 6 months from the time of prescription issuance until medication filling date was exceeded. Treatment changes were based on physician decisions and patient preferences. Demographic data including age, sex, body mass index (BMI), ethnicity, smoking history, and socioeconomic status as well as Charlson comorbidity index were retrieved. Data regarding use of steroids and conventional disease-modifying anti-rheumatic drugs (cDMARDs) were also extracted. Descriptive statistics, including means (standard deviations) for continuous variables and frequencies (%) for categorical variables, were used. Persistence estimates were derived using non-parametric survival analysis using Kaplan-Meier functions, with treatment discontinuations as failure events. Cox regression hazard ratio models were conducted to investigate factors associated with drug persistence. Results: A total of 2301 PsA patients with 2958 treatment periods were identified and included in the analyses. Mean age of the study population was 50.9 ± 14 years, 54% were females, 70.4% were with BMI > 25, 40% were current smokers, and 76% were with a Charlson comorbidity index > 1. The most commonly prescribed drug was etanercept (33%), followed by adalimumab (29%), golimumab (12%), secukinumab (10%), ustekinumab (8%), and infliximab (8%). While approximately 40% of patients persisted on therapy following 20 months of treatment, only about 20% of patients remained on any particular biologic agent after 5 years. Analyzing the data for all treatment periods while taking into account all lines of therapy revealed that secukinumab had a higher persistency than adalimumab, infliximab, and ustekinumab, with a log rank of 0.022, 0.047, and 0.001, respectively. Female sex and smoking were associated with lower drug persistence (HR = 1.25, 95% CI = 1.13–1.38 and HR = 1.109, 95% CI = 1.01–1.21, respectively). On analyzing the data using only the first indicated biologic line, no superiority of any single anti-tumor necrosis factor-alpha (anti-TNFα) agent was observed, while secukinumab was found to be superior as second line therapy to adalimumab, etanercept, infliximab, and ustekinumab but not to golimumab with a log rank P value of 0.001, 0.004, 0.025, and 0.002, respectively. Conclusions: In this large observational cohort studied in the era of biologic therapy, a relatively low drug persistence was observed, with female sex and smoking having a negative impact on persistency. None of the anti-TNFα agents was found to be more persistent than others as first line therapy, while secukinumab was found to be superior to other biologics when indicated as second line of therapy.


  • Open Access

    Comorbidities in Patients with Psoriatic Arthritis

    by Amir Haddad, Devy Zisman

    Epidemiological studies have shown that patients with psoriatic arthritis (PsA) are often affected by numerous comorbidities that carry significant morbidity and mortality. Reported comorbidities include diabetes mellitus, obesity, metabolic syndrome, cardiovascular diseases, osteoporosis, inflammatory bowel disease, autoimmune eye disease, non-alcoholic fatty liver disease, depression, and fibromyalgia. All health care providers for patients with PsA should recognize and monitor those comorbidities, as well as understand their effect on patient management to ensure an optimal clinical outcome.