POS0878 ASSOCIATION OF A LOWER BODY-MASS INDEX WITH THE PRESENCE OF ILD IN SSc PATIENTS – A DERIVATION PREDICTION STUDY USING DECISION TREE-BASED ALGORITHMS

Background

Upper-gastrointestinal involvement (GI) is associated with more severe interstitial lung disease in patients with systemic sclerosis (SSc-ILD). However, there are many unexplored GI risk factors for the presence of SSc-ILD which could be potentially revealed by machine learning algorithms.

Objectives

The aim of our study was to identify GI related risk factors for the presence of SSc-ILD using machine learning algorithms based on decision trees (DT).

Methods

Data of the last follow-up visit from consecutive patients fulfilling the 2013 ACR/EULAR SSc classification criteria recorded in our local EUSTAR registry were used for this study.

The study outcome was the presence of SSc-ILD on high-resolution computed tomography.

Two sets of predictors were identified based on their potential association with GI. The first set contains the following variables available in the EUSTAR registry: esophageal symptoms (dysphagia and reflux), stomach symptoms (early satiety, vomiting), intestinal symptoms (diarrhea, bloating and constipation), malabsorption syndrome, body-mass-index (BMI) and proton pump inhibitor therapy, calcium channel blocker therapy and immunosuppressive therapy. In the second set, we replaced the first three EUSTAR variables of the first set with the scales of the UCLA Gastrointestinal Tract Questionnaire 2.0 (UCLA-GIT).

Of these two sets, the most important variable was selected using three different DT-based algorithms: (1) recursive partitioning and regression trees (RPART) –which uses trees to build decision rules, (2) random forest (RF) - an ensemble of DT built in parallel, and (3) gradient boosting machines (GBM) - an ensemble of DT built sequentially. The selected variables were eventually integrated with established predictors for presence of SSc-ILD (diffuse cutaneous subset, anti-Scl-70 positivity, male gender, forced vital capacity [FVC] and diffusion capacity of the lung for carbon monoxide-single breath [DLCO-SB]) into final prediction models for SSc-ILD presence using RPART, RF and GBM respectively. Their performance was evaluated by C-statistics. The importance of the newly detected predictor was assessed by variable importance plots (VIPs).

Results

We included in our study 334 patients. The median age was 61 [IQR: 50-69] years, 59 (17.7%) were males and 266 (79.6%) had limited cutaneous SSc. Median BMI was 23 [IQR: 21-26] kg/m2, 133 (39.8%) of the patients had SSc-ILD, median FVC% 93 [IQR: 81-105], DLCO 72.5 [56-84] and. Of the UCLA-GIT scales the highest score was for the distension/bloating with a value of 0.50 [IQR: 0-1.24]. Regarding medications, 167 (50%) patients were exposed to PPI, 39 (11.7%) to CCB and 105 (31.4%) to immunosuppressive therapy.

The BMI was deemed by all three algorithms as the most important predictor of SSc-ILD among both sets of GI related variables (Figure 1A-F). The final model, which included established risk factors for presence of ILD and the BMI, supported the importance of BMI in predicting the SSc-ILD. The VIPs obtained by GBM also ranked the BMI as the most important predictor.

Figure 1.

Tree-based algorithms revealing the importance of BMI for prediction of SSc-ILD. Panels A, B and C are variable importance plots (VIPs), which reveals the most important GI-predictor for occurrence of SSc-ILD in the EUSTAR set– the predictor with the highest relative importance is the most important predictor. Panels D, E and F are VIPs reveals the most important GI-predictor for occurrence of SSc-ILD in the UCLA-GIT set.

A lower BMI was associated with presence of SSc-ILD (C-statistics for the RPART, RF and GBM models were 0.79, 0.70 and 0.76, respectively, corresponding to a fair accuracy). As expected, also a lower FVC, and DLCO-SB, and a positivity for Scl-70 ab were associated with presence of ILD.

Conclusion

Lower BMI is a novel promising predictor for the presence of ILD, which should be confirmed in additional analyses.

Disclosure of Interests

Alexandru Garaiman: None declared, Carina Mihai Speakers bureau: MEDtalks Switzerland, Mepha, Rucsandra Dobrota Consultant of: Actelion and Boehringer-Ingelheim, Grant/research support from: Articulum Fellowship, Pfizer, Actelion, Cosimo Bruni Speakers bureau: Eli-Lilly, Actelion, Boehringer-Ingelheim, Grant/research support from: Gruppo Italiano Lotta alla Sclerodermia (GILS), European,, Scleroderma Trials and Research Group (EUSTAR), Scleroderma Clinical Trials Consortium (SCTC), AbbVie, Muriel Elhai: None declared, Suzana Jordan: None declared, Lea Stamm: None declared, Anna-Maria Hoffmann-Vold Speakers bureau: Actelion, Boehringer Ingelheim, Jansen, Roche, Merck Sharp & Dohme, ARXX Therapeutics, Lilly and Medscape, Consultant of: Actelion, Boehringer Ingelheim, Jansen, Roche, Merck Sharp & Dohme, ARXX Therapeutics, Lilly and Medscape, Grant/research support from: Boehringer Ingelheim, Bayer, Oliver Distler Speakers bureau: Bayer, Boehringer Ingelheim, Medscape, Novartis, Roche, Pfizer, Roche, Sanofi, Consultant of: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, ChemomAb, Corbus, CSL Behring, Galapagos, Glenmark, GSK, Horizon, Inventiva, iQvia, Kymera, Lupin, Medac, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Prometheus Biosences, Roche, Roivant, Topadur and UBC, Lilly, Pfizer, Grant/research support from: Kymera, Mitsubishi Tanabe, Mike O. Becker Speakers bureau: Mepha, MSD, Novartis, GSK, Bayer and Vifor

OP0003 DOES IMMUNOSUPPRESSIVE THERAPY IMPROVE GASTROINTESTINAL SYMPTOMS IN PATIENTS WITH SYSTEMIC SCLEROSIS?

Background

The gastrointestinal (GI) tract is frequently affected in systemic sclerosis (SSc), leading to considerable morbidity and even mortality. While important progress has been made in the last years regarding treatment of SSc, there is no disease-modifying treatment available for SSc-related GI involvement.

Objectives

We aimed to identify, in an observational cohort study of real-life patients with SSc, an association between immunosuppressive therapy and the severity of GI symptoms, measured by the University of California at Los Angeles / Scleroderma Clinical Trial Consortium Gastro-Intestinal Tract instrument 2.0 (UCLA GIT 2.0).

Methods

We selected patients from our EUSTAR centre who met the 2013 ACR/EULAR classification criteria for SSc and had at least two visits with completed UCLA GIT 2.0 questionnaires, with an interval of 12±3 months between visits. We defined the first visit with a completed UCLA GIT 2.0 questionnaire as baseline visit. Immunosuppressive therapy was defined as exposure for at least 6 months between the two visits to at least one of the following drugs, regardless of indication: mycophenolate mofetil (MMF), cyclophosphamide, methotrexate, azathioprine, leflunomide, glucocorticoids (>10mg/d prednisone-equivalent), rituximab, tocilizumab, and abatacept. The study outcome was the UCLA GIT 2.0 score at the follow-up visit. We performed multivariable linear regression with this outcome as dependent variable and immunosuppressive therapy during follow-up, immunosuppressive therapy before baseline, baseline UCLA GIT 2.0 score and several baseline parameters selected by clinical judgment as potentially influencing GI symptoms, as independent variables. Multiple imputation was implemented to handle missing values.

Results

We included 209 patients. Baseline characteristics were: 82.3% female, median (IQR) age 59.0 (48.6, 68.2) years, median disease duration 6.0 (2.7, 12.5) years, 40 (19.1%) diffuse cutaneous SSc, median baseline UCLA GIT 2.0 score 0.19 (0.06, 0.43). Of these, 71 patients were exposed to immunosuppressive therapy during the observation period: 27/71 methotrexate, 1/71 cyclophosphamide, 17/71 MMF, 3/71 leflunomide, 3/71 azathioprine, 6/71 glucocorticoids >10mg/d, 16/34 rituximab, 18/34 tocilizumab. Patients on immunosuppressive therapy during the observation period had, compared to patients without such treatment, overall more severe SSc, higher prevalence of treatment with proton pump inhibitors, similar UCLA GIT 2.0 scores at baseline and at follow up and tendentially less severe GI symptoms at baseline and follow-up by medical history. In multivariable linear regression, immunosuppressive therapy, lower body mass index, longer disease duration and lower baseline UCLA GIT 2.0 score were significantly associated with lower (better) UCLA GIT 2.0 scores at follow-up (Table 1).

Table 1.Predictors of UCLA GIT 2.0 score at follow-upEstimates95% CIpAge0.002-0.001 – 0.0060.136Sex [male]-0.056-0.172 – 0.0610.347Disease duration-0.005-0.009 – -0.0000.030Body mass index0.0140.002 – 0.0250.017UCLA GIT 2.0 total score baseline0.6900.571 – 0.809<0.001Immunosuppressive therapy during observation period-0.119-0.228 – -0.0100.032Immunosuppressive therapy before baseline0.080-0.032 – 0.1920.160Modified Rodnan Skin Score-0.001-0.008 – 0.0070.860Forced vital capacity-0.001-0.004 – 0.0010.302Erythrocyte sedimentation rate0.003-0.001 – 0.0060.116Proton pump inhibitors-0.034-0.120 – 0.0520.435(Intercept)-0.120-0.531 – 0.2910.566

Baseline factors associated with the total UCLA GIT 2.0 score at the end of the observation period. Multiple linear regression model with imputation for missing variables. N=209 patients

Conclusion

Immunosuppressive treatment was associated with lower UCLA GIT 2.0 scores, which suggests potential effects of immunosuppressants on GI manifestations in patients with SSc. These results need verification in additional studies and randomised controlled clinical trials.

References

[1]Khanna D et al. Arthritis Rheum, 2009; 61: 1257-63.

Disclosure of Interests

Lea Stamm: None declared, Alexandru Garaiman: None declared, Norina Zampatti: None declared, Mike O. Becker Speakers bureau: Mepha, MSD, Novartis, GSK, Bayer and Vifor, Consultant of: Mepha, MSD, Novartis, GSK, Bayer and Vifor, Grant/research support from: Mepha, MSD, Novartis, GSK, Bayer and Vifor, Cosimo Bruni Speakers bureau: Actelion, Eli-Lilly, Boehringer-Ingelheim, Grant/research support from: Abbvie, EUSTAR, Gruppo Italiano Lotta alla Sclerodermia (GILS), SCTC, Rucsandra Dobrota Consultant of: Boehringer-Ingelheim, Grant/research support from: Iten-Kohaut Foundation, Muriel Elhai: None declared, Sherif Ismail Grant/research support from: EULAR scientific training grant for young fellows 2021, Suzana Jordan: None declared, Aurora Tatu: None declared, Oliver Distler Speakers bureau: Bayer, Boehringer Ingelheim, Janssen, Medscape, Consultant of: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, 4P Science, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur, Grant/research support from: Kymera, Mitsubishi Tanabe, Boehringer Ingelheim, Carina Mihai Speakers bureau: Boehringer-Ingelheim, Mepha, MED Talks Switzerland, Consultant of: Boehringer-Ingelheim, Janssen, Grant/research support from: Boehringer-Ingelheim, Janssen, Roche.

Zika and travel in the news: a content analysis of US news stories during the outbreak in 2016-2017

OBJECTIVES

This study aimed to understand what information the US media communicated about Zika virus (ZIKV) and travel in 2016 and 2017.

STUDY DESIGN

We conducted a content analysis of news coverage about ZIKV and travel from April 5, 2016 to March 31, 2017.

METHODS

We obtained a stratified, random sample of English language, US print newspaper and television news coverage about ZIKV and travel. We developed a coding scheme to assess key messages in the news, including how ZIKV is transmitted, the symptoms and outcomes of ZIKV infection, and recommended prevention behaviors.

RESULTS

Almost all news stories mentioned mosquito-borne transmission (96.8%) and just over half mentioned sexual transmission (55.3%). News stories were more likely to talk about ZIKV outcomes (78.8%) than ZIKV symptoms (40.6%). However, outcomes affecting babies were mentioned more frequently than outcomes affecting adults. Recommendations included a wide array of protective behaviors, such as delaying or avoiding travel (77.6%) and using mosquito repellent (41.0%). However, few studies (10.9%) mentioned barriers to practicing ZIKV prevention behaviors.

CONCLUSIONS

Public health organizations and professionals can use these findings to help improve communication about future outbreaks of mosquito-borne illnesses. We also recommend conducting real-time monitoring of news media and frequent content analysis of news stories to ensure coverage provides the information the public needs.

Characterization of a novel allele, HLA-C*02:135N, by full-length gene sequencing in a bone marrow donor

A frameshift because of a two-nucleotide deletion results in an HLA-C null allele, HLA-C*02:135N.

A novel HLA-A*26 allele, HLA-A*26:01:44, identified in a Caucasian individual

HLA-A*26:01:44 differs from HLA-A*26:01:01 by a single substitution in exon 5.

The novel HLA-B*08:183 allele identified by sequence-based typing in a Caucasian leukemia patient

HLA-B*08:183 differs from HLA-B*08:01:01 by a single substitution in exon 5.

HLA-A*23:01:19, a novel variant of HLA-A*23:01, discovered in a West African stem cell transplantation patient

HLA-A*23:01:19 differs from HLA-A*23:01:01 by a single substitution in exon 4.

A novel HLA-B allele, B*4093, sharing sequences with B*4006 and B*0702 in an Asian Indian donor

A new HLA-B allele (B*4093) in a North Indian Hindu donor differing from B*4006 by four nucleotide substitutions in codon 41.1, codon 44.3, codon 45.1 and codon 50.3 has been identified. This novel allele was part of the A*0211-B*4093-Cw*1502-DRB1*15-DQB1*06 HLA haplotype.

Pudendal nerve terminal motor latency influences surgical outcome in treatment of rectal prolapse

PURPOSE

This study was undertaken to document the effect of pudendal nerve function on anal incontinence after repair of rectal prolapse.

METHODS

Patients with full rectal prolapse (n = 24) were prospectively evaluated by anal manometry and pudendal nerve terminal motor latency (PNTML) before and after surgical correction of rectal prolapse (low anterior resection (LAR; n = 13) and retrorectal sacral fixation (RSF; n = 11)).

RESULTS

Prolapse was corrected in all patients; there were no recurrences during a mean 25-month follow-up. Postoperative PNTML was prolonged bilaterally (> 2.2 ms) in six patients (3 LAR; 3 RSF); five patients were incontinent (83 percent). PNTML was prolonged unilaterally in eight patients (4 LAR; 4 RSF); three patients were incontinent (38 percent). PNTML was normal in five patients (3 LAR; 2 RSF); one was incontinent (20 percent). Postoperative squeeze pressures were significantly higher for patients with normal PNTML than for those with bilateral abnormal PNTML (145 vs. 66.5 mmHg; P = 0.0151). Patients with unilateral abnormal PNTML had higher postoperative squeeze pressures than those with bilateral abnormal PNTML, but the difference was not significant (94.8 vs. 66.5 mmHg; P = 0.3182). The surgical procedure did not affect postoperative sphincter function or PNTML.

CONCLUSION

Injury to the pudendal nerve contributes to postoperative incontinence after repair of rectal prolapse. Status of anal continence after surgical correction of rectal prolapse can be predicted by postoperative measurement of PNTML.

Caring for the patient with peristomal pyoderma gangrenosum

Pyoderma gangrenosum is an ulcerating skin condition associated with inflammatory bowel disease and other diseases. During and 18-month period beginning in the fall of 1991, seven patients were followed up for pyoderma gangrenosum. Three of these cases, with assessment and treatment plans, are presented. A discussion of treatment principles for managing pyoderma gangrenosum follows.

Primary hyperparathyroidism in Austria: results of an 8-year prospective study

Serum calcium determinations in 45,217 hospitalized patients during an 8 year period revealed sustained hypercalcemia in 124 (0.3%) patients. Further clinical and biochemical investigations established primary hyperparathyroidism (PHP) in at least 40 (32%) patients, an incidence of PHP of 89.6 +/- 41.5 per 100,000 patients per year. The incidence of PHP in males and females was 31.5 and 124.2 per 100,000, respectively. The highest incidence was found in females greater than 66 years of age (268.8 per 100,000). Nineteen (48%) patients showed classical symptoms of PHP, 14 (35%) patients were minimally symptomatic, and 7 (17%) patients were asymptomatic. The incidence and symptomatology of PHP in Austria is nearly the same as in other countries. Because of the multiple actions of parathyroid hormone in the body, PHP can cause debilitating symptoms but too often it remains undiagnosed clinically. Routine calcium determinations are very important and PHP must always be considered in the differential diagnosis, especially in minimally symptomatic patients.

Interaction of spirochetes with the host

The success of an invading organism must depend on several cytoplasmic, surface-associated and secreted factors. The technical difficulties in handling pathogenic spirochetes like Treponema pallidum and Borrelia burgdorferi have made it difficult to define specific factors involved in entry and long-term survival. The problem of defining virulence factors has been attacked by several strategies: T. pallidum secretes a number of immunogenic low molecular mass proteins. The most predominant are of molecular weight 15.5 and 22 kDa. Preliminary data suggest that antibodies against these proteins induce protective immunity in rabbits experimentally infected with T. pallidum. Many potentially important surface-associated antigens of T. pallidum have now been cloned and characterized. Two of these, TpD and TpE, are lipoproteins which exhibit characteristic size heterogeneity. The apparent molecular weight of TpE from T. pallidum and T. pertenue are different. The clinical symptoms in syphilis and yaws are very different, but sequence analysis of TpE has shown that the TpE proteins are indeed very similar in the two strains. This observation makes it unlikely that heterogeneity of TpE can account for the different clinical symptoms of syphilis and yaws. Sequence data for another newly sequenced surface-associated antigen of T. pallidum (molecular weight 41 kDa) indicate that this protein is involved in glucose transport and chemotaxis/motility. Intracellular factors like the molecular chaperonin GroEL have been documented both in treponemes and borreliae. This stress protein is involved in cellular repair processes and folding/assembly of protein subunits. Indirect evidence suggests that GroEL affects the ability of spirochetes to survive in the stressful environment of the infected host. Several lines of evidence suggest that the Osp proteins of Borrelia are important for host/parasite interaction. Further support for this idea has come from studies of a series of monoclonal antibodies against OspA. A monoclonal antibody against OspA (9B3D) is able to block attachment of B. burgdorferi to a cell monolayer. Borrelia loses infectivity after several passages in vitro. The loss of pathogenicity is associated with loss of specific plasmids and proteins. One of the low-passage-associated proteins (Lap30) has been cloned and sequenced. Lap30 is a lipoprotein encoded by a 38-kb plasmid, not present in high passage B. burgdorferi. Aberrant immunological processes induced by the lipopolysaccharide component of Treponema hyodysenteriae could explain the dramatic intestinal lesions in swine dysenteriae. But analysis by TLC reveals that the LPS of this treponeme is different from classical Salmonella LPS.(ABSTRACT TRUNCATED AT 400 WORDS)