Risk factors of mortality in hospitalized patients with COVID-19 applying a Machine Learning algorithm

Introduction

Risk stratification of patients with COVID-19 can be fundamental to support clinical decision-making and optimize resources. The objective of our study is to identify among the routinely tested clinical and analytical parameters those that would allow us to determine patients with the highest risk of dying from COVID-19.

Material and methods

We carried out a retrospective cohort multicentric study by consecutively, including hospitalized patients with COVID-19 admitted in any of the 11 hospitals in the healthcare network of HM Hospitals-Spain. We collected the clinical, demographic, analytical, and radiological data from the patient's medical records.

To assess each of the biomarkers’ predictive impact and measure the statistical significance of the variables involved in the analysis, we applied a random forest with a permutation method. We used the similarity measure induced by a previously classification model and adjusted the k-groups clustering algorithm based on the energy distance to stratify patients into a high and low-risk group. Finally, we adjusted two optimal classification trees to have a schematic representation of the cut-off points.

Results

We included 1246 patients (average age of 65.36 years, 62% males). During the study one hundred sixty-eight patients (13%) died. High values of age, D-Dimer, White Blood Cell, Na, CRP, and creatinine represent the factors that identify high-risk patients who would die.

Conclusions

Age seems to be the primary predictor of mortality in patients with SARS-CoV-2 infection, while the impact of acute phase reactants and blood cellularity is also highly relevant.

Early monitoring of infliximab serum trough levels predicts long-term therapy failure in patients with axial spondyloarthritis

Objective: To evaluate whether serum infliximab trough levels (ITL) during the early stages of treatment are predictive of long-term clinical failure in patients with axial spondyloarthritis (axSpA).Method: Longitudinal observational study involving 81 patients with axSpA monitored during infliximab therapy. Serum ITL were measured before starting infliximab treatment and at weeks 2 (W2), W6 and W12 of treatment. Disease activity was assessed by Ankylosing Spondylitis Disease Activity Score (ASDAS) at baseline, W24 and W52, and every 6 months thereafter until treatment discontinuation, regardless of the reason. Non-clinically important improvement was defined by ΔASDAS<1.1. The association between serum levels during the early stages and clinical outcomes (non-clinically important improvement at W52, drug survival and drop-out due to secondary inefficacy) was investigated through logistic regression models and Kaplan Meier curves. Receiver operating characteristic (ROC) curves were employed to determine the best cut-off for serum ITL.Results: Out of the 81 patients, 45 (56%) did not achieve clinical improvement at W52. These patients had lower serum ITL at W12 compared to those who improved: ITL [median (IQR)]: 4.1(0.9-8.3) µg/mL vs 7.1 (4.3-11.3) µg/mL, respectively;p = 0.007). ITL<6.7 µg/mL at W12 was significantly associated with: i) not achieving clinical improvement at W52 (OR: 2.3; 95%CI: 1.3-3.9); ii) shorter drug survival (5.0 years (95% CI 3.8-6.2) vs 7.0 years (95% CI 4.8-6.9; p = 0.04), and iii) higher drop-out rates due to secondary inefficacy (OR: 3.5; 95% CI: 1.2-10.2).Conclusion: Low serum ITL at W12 were associated with long-term clinical failure in patients with axSpA, due to secondary inefficacy.

POS0617 ANTI INFLIXIMAB ANTIBODIES DETECTED BY A DRUG TOLERANT ASSAY ARE FREQUENT BUT, IN MANY CASES, WITHOUT RELEVANT CLINICAL SIGNIFICANCE

Background:

Infliximab (Ifx) has proven effective in treating rheumatoid arthritis (RA) and spondyloarthropathies (SpA), although around 40% of cases fails, mainly due to immunogenicity. Formation of immunocomplexes between antibodies to Ifx (ATI) and Ifx can increase drug clearance, leading to treatment failure. Standard ELISA assays which are drug -sensitive are frequently used, being able to detect only free ATI. Interest in drug-tolerant assays to measure total ATI (free and complexed) is increasing.

Objectives:

To compare the development of ATI using both drug-tolerant and drug-sensitive assays at early stages of Ifx therapy. To analyse the relationship of ATI detected by both assays with the drop-out of treatment.

Methods:

This is a prospective observational study including 45 patients with RA and 61 with axial-SpA treated with standard doses of Ifx (3mg/kg and 5mg/kg, respectively) enrolled at Biological Therapy Unit of Hospital La Paz. Serum samples were obtained at 2, 6, 12 and 22 weeks (W) after Ifx initiation. The data about discontinuation for inefficacy was obtained from the database. ATI presence was evaluated by a drug-sensitive in-house two-site (bridging) ELISA (bELISA) and a drug-tolerant commercial ELISA assay (Immundiagnostik®,IDK). All comparisons were performed throughout non-parametrical test. In SpA group, due to the low number of ATI+ patients at W12 by bELISA the statistical analysis to compare both assays were not performed.

Results:

ATI detection by both assays at early stages (≤22 W) of treatment is shown in Table 1a. ATI were always detected earlier by IDK than bELISA and also in RA than in SpA patients probably reflecting the effect of lower Ifx doses. Three out of 106 (3%) vs 0 (0%) patients had ATI at W 2 and 62 (58%) vs 20 (18%) patients at W22, by IDK and bELISA, respectively.

Table 1.

Patient characteristics of all included patients

W2W6W12W22ARSpAARSpAARSpAARSpAa) ATI+ patients (n, %) at early stagesbELISA003(7%)010(22%)1(2%)13(29%)7(12%)IDK1(2%)2(3%)7(16%)2(3%)16(36%)16(26%)28(62%)34(56%)b) Patients who discontinued (n, %) Ifx therapy considering ATI status at early stagesbELISA+9(90%)*1(100%)*12(92%)4(57%)bELISA-23(66%) 22(37%)20(63%)19(35%)IDK+15(94%)*7(44%)24(86%)13(38%)IDK-17(59%)11(24%)13(77%)10(27%)

*p<0.05 comparing between ATI+ vs ATI- in each assay.

Once ATIs appeared, regardless both methods, they persisted throughout the follow-up, indicating that immunogenicity was not transient.

At W22, only 13/28 (46%) and 7/34 (21%) patients with ATI detected by IDK were also positive by bELISA in RA and SpA, respectively.

ATI levels by IDK were higher in ATI+ by bELISA than in ATI- patients at early stages: ATI levels by IDK at W12: 91[74-348] ng/ml ATI+ vs 21.7[15-59.5] ng/ml ATI- (p<0.01) and at W22: 132 [89-372] ng/ml ATI+ vs 23[13-66] ng/ml ATI- (p<0.001). However, only in 4% (2/45) patients with RA and in 13% (8/61) patients with SpA the detection by IDK was earlier than by bELISA at W12.

Free IFX in serum was not detected in bELISA ATI+ patients. In IDK ATI+ patients low circulating Ifx levels were present as compare to ATI- since W6 to the end of follow-up (p<0.01).

More ATI+ patients dropped out Ifx at W12 and W22 regardless de assay (Table 1.b), being statistically significant for both assays in patients with RA and only for bELISA in patients with SpA.

Conclusion:

ATI measured by a drug-tolerant assay are always detected earlier than ATI detected by bELISA, indicating that immunogenicity, at least with Ifx, is usually an early event. High levels of ATI by IDK are associated with an earlier detection by bELISA in case of RA patients. ATI detected only by drug tolerant assays are associated with low levels of circulating Ifx but not with a complete drug neutralization and may do not have clinical relevance compared to ATI detected by bELISA. Many patients have low levels of ATI which can only be detected by drug tolerant assays after long-term of follow-up.

The reasons why ATI levels rise rapidly in some patients while in others remain low are currently unknown but may be relevant if the clinical effect of immunogenicity is to be minimized.

Acknowledgements:

We are grateful to all the rheumatologists and nurses of the Daycare Department for Biologics and to the laboratory technicians of the Immunological Unit

Disclosure of Interests:

ANA MARTÍNEZ-FEITO: None declared, Borja Hernández-Breijo: None declared, Marta Novella-Navarro: None declared, Victoria Navarro-Compán Grant/research support from: AbbVie, Janssen, Lilly, Novartis, Pfizer, and UCB, Cristina Diego: None declared, Irene Monjo: None declared, Laura Nuño: None declared, Alejandro Villalva: None declared, Diana Peiteado: None declared, DORA PASCUAL-SALCEDO: None declared, Pilar Nozal: None declared, Alejandro Balsa Grant/research support from: Abbvie, Pfizer, Novartis, Roche.Amgen, Sandoz, Lilly, UCB. Personal fees and non- financial support from BMS. Grants, personal fees and non- financial support from Nordic., Chamaida Plasencia Grant/research support from: AbbVie, Lilly, Novartis, Pfizer,Sanofi, Biogen and UCB.

Low-voltage chest CT: another way to reduce the radiation dose in asbestos-exposed patients

AIM

To assess whether low voltage chest computed tomography (CT) can be used to successfully diagnose disease in patients with asbestos exposure.

MATERIALS AND METHODS

Fifty-six former employees of the shipbuilding industry, who were candidates to receive a standard-dose chest CT due to their occupational exposure to asbestos, underwent a routine CT. Immediately after this initial CT, they underwent a second acquisition using low-dose chest CT parameters, based on a low potential (80 kV) and limited tube current. The findings of the two CT protocols were compared based on typical diseases associated with asbestos exposure. The kappa coefficient for each parameter and for an overall rating (grouping them based on mediastinal, pleural, and pulmonary findings) were calculated in order to test for correlations between the two protocols.

RESULTS

A good correlation between routine and low-dose CT was demonstrated for most parameters with a mean radiation dose reduction of up to 83% of the effective dose based on the dose-length product between protocols.

CONCLUSIONS

Low-dose chest CT, based on a limited tube potential, is useful for patients with an asbestos exposure background. Low-dose chest CT can be successfully used to minimise the radiation dose received by patients, as this protocol produced an estimated mean effective dose similar to that of an abdominal or pelvis plain film.

Use of supercritical fluid extraction and gas chromatography-mass spectrometry to obtain amino acid profiles from several genetically modified varieties of maize and soybean

A method using supercritical fluid extraction (SFE) and gas chromatography-mass spectrometry (GC/MS) for obtaining the amino acid profiles of genetically modified maize and soybean is proposed. SFE is carried out in a homemade modular system where amino acids are extracted with carbon dioxide modified with 35% of methanol, in conditions optimized by a central composite design. Once extracted, the amino acids are determined by GC/MS. The method has been applied to three samples of maize derived from MON810, other from NK 603 and a Roundup ready soybean sample. The profiles are compared with those obtained from their corresponding isogenic non-transgenic varieties. Although differences are directly observed in some cases by visual comparison of the chromatograms, the application of ANOVA shows more significant differences. In general terms, isogenic varieties seem to have higher content of several amino acids.

Biweekly nonpegylated liposomal doxorubicin (M) and docetaxel (T) as neoadjuvant treatment in patients with stage II-III breast cancer

11049

Background: We have previously reported (ASCO 2006) the efficacy and toxicity of 4 courses of M (75mg/m2) and T (75mg/m2) with G-CSF support in a 21 day schedule as neoadjuvant treatment in patients with resectable breast cancer. Aim: To evaluate the clinical and pathological response rate (RR) and toxicity of biweekly M and T given prior to surgery in patients with breast cancer. Methods: Patients with histological confirmation of breast cancer (stage II-III and inflammatory), age >18 years, left ventricular ejection fraction > 45% and adequate bone marrow, renal and hepatic function were included in the study. Prior systemic therapy, radiotherapy or surgery for breast cancer were not allowed. The treatment was: M (60 mg/m2) and T (60mg/m2) each in 1 hour infusion, with subcutaneous G-CSF (5 mcg/kg) support on days 4–9. Courses were repeated every 14 days. Patients received 6 courses prior to surgery. Results: To date 45 patients have been enrolled; 20 who have completed therapy and underwent surgery (except for patients with progression) were included in this interim analysis. Median age: 48 years (38–63), ECOG PS 0: 90%, ECOG PS1: 10%, postmenopausal: 35%. Histology was infiltrating ductal carcinoma in 80%. Patients received a total of 110 courses (median 6, range 2–6). Efficacy: Of 19 evaluable patients, 4 achieved a clinical complete response (cCR) (21%), 12 partial response (cPR) (63%), 1 stable disease (cSD) (5%) and 2 progressive disease (cPD) (10%), resulting in a clinical response rate (cRR) of 84%. Surgery was performed in 17 (85%) patients, 4 (23%) of them had pathological complete response (pCR), 12 (70%) partial response (pPR), 1 (6%) stable disease (pSD), resulting in a pathological RR of 93%. Median time to progression and overall survival have not been reached. Toxicity: Hematological grade III/IV toxicities per patient were neutropenia (10%), febrile neutropenia (10%) and thrombocytopenia (5%). Non-hematological grade III/IV toxicities per patient were mucositis (10%), nausea/vomiting (10%) and epigastralgia (10%) Conclusions: Six courses of T and M every 14 days with G- CSF support as induction treatment in stage II and III breast cancer are active and well tolerated.

No significant financial relationships to disclose.