Hospitalized patients with positive antiphospholipid antibodies who have low complement levels are at increased risk for death-a retrospective cohort study.

PURPOSE: To investigate whether low complement levels can predict worse outcomes in patients hospitalized with positive anti-phospholipid antibodies. METHODS: This was a retrospective cohort study. We obtained demographics, laboratory, and prognostic data of all consecutive patients hospitalized between 2007 and 2021, for whatever reason, with at least one positively abnormal anti-phospholipid antibody, who were also tested for complement levels (C3 or C4). We then compared the rates of long-term mortality, 1-year mortality, deep vein thrombosis, and pulmonary emboli between groups of low complement and normal complement levels. Multivariate analysis was used to control for levels of clinical and laboratory confounders. RESULTS: We identified 32,286 patients tested for anti-phospholipid antibodies. Of those patients, 6800 tested positive for at least one anti-phospholipid antibody and had a documented complement level. Significant higher mortality rates were found in the low complement group, with an odds ratio for mortality (OR 1.93 CI 1.63-2.27 p < .001). Deep vein thrombosis and pulmonary emboli rates were similar. Multivariate analysis confirmed that low complement was an independent predictor for mortality after controlling for age, sex, dyslipidemia, chronic heart failure (CHF), chronic kidney disease (CKD), and anemia. CONCLUSIONS: Our study results indicate that low complement is associated with significantly higher mortality rates in admitted patients with elevated levels of anti-phospholipid antibodies. This finding correlates with recent literature suggesting a vital role for complement activation in anti-phospholipid syndrome.

The effect of mechanical bowel preparation on postoperative complications in laparoscopic right colectomy: a retrospective propensity score matching analysis.

PURPOSE: To assess whether full bowel preparation affects 30-day surgical outcomes in laparoscopic right colectomy for colon cancer. METHODS: A retrospective chart review of all elective laparoscopic right colectomies performed for colonic adenocarcinoma between Jan 2011 and Dec 2021. The cohort was divided into two groups-no bowel preparation (NP) group and patients who received full bowel preparation (FP), including oral and mechanical cathartic bowel preparation. All anastomoses were extracorporeal stapled side-to-side. The two groups were compared at baseline and then were matched using propensity score based on demographic and clinical parameters. The primary outcome was 30-day postoperative complication rate, mainly anastomotic leak (AL) and surgical site infection (SSI) rate. RESULTS: The original cohort included 238 patients with a median age of 68 (SD 13) and equal M:F ratio. Following propensity score matching, 93 matched patients were included in each group. Analysis of the matched cohort showed a significantly higher overall complication rate in the FP group (28 vs 11.8%, p = 0.005) which was mostly due to minor type II complications. There were no differences in major complication rates, SSI, ileus, or AL rate. Although operative time was significantly longer in the FP group (119 vs 100 min, p ≤ 0.001), length of stay was significantly shorter in the FP group (5 vs 6 days, p = 0.001). CONCLUSIONS: Aside from a shorter hospital stay, full mechanical bowel preparation for laparoscopic right colectomy does not seem to have any benefit and may be associated with a higher overall complication rate.

Small Bowel Obstruction in Patients without Prior Abdominal Surgery: To Operate or Not?

INTRODUCTION: Surgical exploration is still considered mandatory in the setting of small bowel obstruction (SBO) in patients without prior intra-abdominal surgery. However, recent studies have challenged this 'classic' approach describing success with conservative non-surgical treatment. The aim of this study is to identify clinical, radiological and biochemical variables that may be associated with the absence of intra-abdominal pathology in patients with SBO who have not undergone previous surgery. METHODS: This is a retrospective cohort study of prospectively recorded data. Patients with SBO without prior abdominal surgery who presented to a single tertiary referral medical center between 2009 and 2019 were included. RESULTS: Eighty-seven patients were included of whom 61(70.0%) were allocated to the 'therapeutic exploration' group and 26 (30.0%) to the 'non-therapeutic exploration' group. Forty-eight patients (55.0%) had adhesions, 17.2% had closed-loop obstruction, 10.0% had an internal hernia, 27.6% had bowel ischemia and 5.7% had bowel necrosis. Although multiple clinical, laboratory, radiological and preoperative factors were examined, none were significantly associated with pathological findings during surgical exploration. There was no statistically significant difference in the incidence of complications when comparing between those groups. CONCLUSIONS: In this series, no variables were associated with intra-abdominal pathology in patients who underwent surgery for SBO with no history of prior abdominal surgery. However, the fact that 27.0% had ischemic bowel upon surgical exploration suggests that this approach is still mandatory for this specific group of patients. Furthermore, clinicians and patients should be aware that negative exploration may be expected in up to 30.0%.

Pyogenic Liver Abscess: Contemporary Trends in a Tertiary Institute.

Background: Pyogenic liver abscess (PLA) is an uncommon but potentially life-threatening condition. In recent years, advances in diagnostics and management have led to early diagnosis and treatment and decreased mortality. We present recent data from a large series of patients with PLA and examine the trends in the management of PLA over a period of 50 years. Methods: The medical records of all patients admitted to the Shaare Zedek Medical Center, Israel, between January 2011 and December 2021 with a primary or secondary diagnosis of PLA were reviewed retrospectively. Results: : Ninety-five patients with PLA were identified. Thirty-eight (40%) were female. The median patient age was 66 years (range 18-93). The diagnosis of PLA in all patients was confirmed with abdominal computed tomography (CT). In twenty patients (21.1%), PLA was not diagnosed by the initial abdominal US. Most abscesses were right-sided. Biliary tract origin was the most common underlying cause of PLA (n = 57, 60%), followed by cryptogenic etiology (n = 28, 30%). Escherichia coli, Klebsiella pneumoniae, and Streptococcus species were most commonly identified. The most common primary treatment modality was percutaneous drainage (PD), which was performed in 81 patients (85.3%). Fourteen patients (14.7%) were treated medically without intervention, and two patients (2.1%) were treated surgically following a failure of PD. Four patients died as a direct result of PLA. Conclusions: Patients diagnosed with PLA are older, the male predominance is less pronounced, and the offending pathogens are likely to originate from the biliary tract. This study questions the utility of abdominal US as the initial diagnostic imaging in patients with suspected PLA (versus CT) and demonstrates improved outcomes for patients with PLA over the years.

Can laboratory evaluation differentiate between coronavirus disease-2019, influenza, and respiratory syncytial virus infections? A retrospective cohort study.

AIM: To identify clinical and laboratory parameters that can assist in the differential diagnosis of coronavirus disease 2019 (COVID-19), influenza, and respiratory syncytial virus (RSV) infections. METHODS: In this retrospective cohort study, we obtained basic demographics and laboratory data from all 685 hospitalized patients confirmed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza virus, or RSV from 2018 to 2020. A multiple logistic regression was employed to investigate the relationship between COVID-19 and laboratory parameters. RESULTS: SARS-CoV-2 patients were significantly younger than RSV (P=0.001) and influenza virus (P=0.022) patients. SARS-CoV-2 patients also displayed a significant male predominance over influenza virus patients (P=0.047). They also had significantly lower white blood cell count (median 6.3×106 cells/µ) compared with influenza virus (P<0.001) and RSV (P=0.001) patients. Differences were also observed in other laboratory values but were insignificant in a multivariate analysis. CONCLUSIONS: Male sex, younger age, and low white blood cell count can assist in the diagnosis of COVID-19 over other viral infections. However, the differences between the groups were not substantial enough and would probably not suffice to distinguish between the viral illnesses in the emergency department.

Enhanced Recovery Deviation and Failure After Pancreaticoduodenectomy: Causative Factors and Impact.

BACKGROUND: Enhanced recovery after surgery (ERAS) following pancreaticoduodenectomy (PD) is popular and safe. This study aimed to describe the incidence, causative factors, and clinical impact of deviation from and failure of an ERAS protocol. MATERIALS AND METHODS: A prospective cohort analysis of elective PD patients managed according to an ERAS protocol between October 2015 and June 2018 was performed. Univariate and multivariate analyses identified variables associated with protocol deviation and failure. The relationship between protocol deviation and failure was also explored. RESULTS: A total of 97 patients were identified comprising of 46 females and 51 males. The median age was 68 y (range 17-85). Twenty-one patients (21.6%) suffered serious complications, whereas two (2.1%) died perioperatively. The median length of stay (LoS) was 14 d (6-36). In total, 73 (75.3%) patients deviated, whereas 39 (40.2%) failed the protocol. On univariate analysis, protocol deviation was associated with male gender, surgery time ≥270 min, and prolonged LoS. On multivariate analysis only prolonged LoS remained significant. Only serious complications were associated with protocol failure on multivariate analysis. Protocol deviation was not associated with significant complications nor ERAS protocol failure. CONCLUSIONS: ERAS protocol deviation does not alter the course of those destined to protocol failure. Greater understanding into the causative factors of either protocol deviation or failure may be the only way to personalize care and realize the maximal benefit of ERAS in this specific group of patients.

Ferritin as a Marker of Severity in COVID-19 Patients: A Fatal Correlation.

BACKGROUND: Ferritin, the cellular protein storage for iron, has emerged as a key molecule in the immune system, orchestrating the cellular defense against inflammation. At the end of 2019, the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) rapidly spread throughout China and other countries around the world, resulting in a viral pandemic. OBJECTIVES: To evaluate the correlation between ferritin and disease severity in coronavirus disease-2019 (COVID-19). METHODS: In this cross-sectional study, we obtained clinical and laboratory data regarding 39 hospitalized patients with confirmed COVID-19 from two hospitals in Israel. RESULTS: A significant increase in ferritin levels was demonstrated in patients with moderate and severe disease, compared to patients with mild disease (P = 0.006 and 0.005, respectively). Severe patients had significantly higher levels of ferritin (2817.6 ng/ml) than non-severe patients (708.6 ng/ml) P = 0.02. CONCLUSIONS: In this preliminary cross-sectional study, elevated ferritin levels were shown to correlate with disease severity in 39 patients from Israel with confirmed COVID-19 infection. Our results further strengthen the hypothesis that severe COVID-19 disease might be due to an underlying dysregulated hyperimmune response. In order to identify these patients early and prioritized resources, we believe that all patients with COVID-19 should be screened for hyperferritinemia.

Characteristics of Pericardial Biopsy: 100 Cases in a Single Center.

BACKGROUND: Pericardial biopsies are rarely performed during the diagnosis and management of pericardial diseases. The circumstances and clinical profile of patients undergoing pericardial biopsies are largely uncharacterized. OBJECTIVES: To examine the circumstances in which pericardial biopsies are obtained and to evaluate their diagnostic yield. METHODS: We studied a total of 100 cases (71% males, mean age 60.8 years, range 8.1-84.5 years) of surgically resected pericardium specimens obtained from 2000 to 2015 at Sheba Medical Center, the largest medical center in Israel. Patients were classified into groups according to four major histological etiologies: idiopathic pericarditis, constrictive pericarditis, malignant pericarditis, and post-cardiac injury syndrome (PCIS). The clinical history and course, laboratory, echocardiography, and histological results were reviewed retrospectively. RESULTS: Causes of pericarditis according to histological definitions included idiopathic pericarditis (29%), constrictive pericarditis (29%), PCIS (9%), and malignant pericarditis (26%). Overall sensitivity of the pericardial biopsy in patients with malignancy was 57.7%. During the study period, we found a trend toward an increased number of biopsies due to constrictive pericarditis and PCIS, along with a decrease in the number of biopsies performed in patients with malignant or idiopathic pericarditis. The diagnosis following biopsy did not change for any of the patients. CONCLUSIONS: Our findings suggest a low diagnostic yield from pericardial biopsies, especially in malignant pericarditis. This conclusion, along with novel therapies, resulted in the infrequent use of pericardial biopsy in recent years.

[INTRACHOLECYSTIC PAPILLARY-TUBULAR NEOPLASM: A NEW PATHOLOGY OF THE GALLBLADDER?]

INTRODUCTION: The clinicopathologic characterization of tumoral intra-epithelial neoplasms of the gallbladder is fairly limited compared to that of similar tumors of the pancreatobiliary system. Until recently, pre-malignant lesions of the gallbladder were mostly reported as adenomas, which were microscopic and therefore regarded as benign and clinically inconsequential, whereas papillary lesions have been largely regarded as a papillary subtype of gallbladder invasive adenocarcinoma. In an attempt to create a unified terminology for these tumors, the term Intracholecystic papillary-tubular neoplasm (ICPN) was proposed to include all exophytic intra-epithelial tumors of the gallbladder measuring ≥1 cm under one category. A few studies which have retrospectively analyzed tumors fulfilling this category found them to be remarkable analogous to the more well-characterized intra-epithelial tumors of the pancreato-biliary system such as IPMN of the pancreas and IPNB of the bile ducts and as such they also represent an 'adenoma-carcinoma' sequence in the gallbladder. Since then a number of case series have been published which attempted to characterize the clinical and pathological features of these tumors and their relationship with invasive carcinoma. In this paper we report three cases of ICPN which represent different stages of the 'adenoma-carcinoma' sequence.

[SARCOPENIA IS AN INDEPENDENT RISK FACTOR FOR DELAYED GASTRIC EMPTYING AFTER PANCREATICODUODENECTOMY].

BACKGROUND: Sarcopenia is defined as the degenerative loss of skeletal muscle and can be measured using the cross-sectional diameter of the psoas muscle on computed tomography. Sarcopenia has been associated with a variety of post-operative complications. We propose that sarcopenia acts as an independent factor predictive of delayed gastric emptying (DGE) after elective pancreaticoduodenectomy (PD). METHODS: A retrospective analysis of a prospectively maintained database of all patients undergoing PD at our tertiary hepatobiliary center was performed for the period December 2014 - March 2017. For each patient, the preoperative cross-sectional diameter of the psoas muscle at the upper border of L4 was calculated. Measurements in the lowest third of gender specific groups were considered to be sarcopenic. The presence of DGE, post-operative pancreatic fistulas (POPF) and major postoperative complications graded as Clavien Dindo III or more were included in the analysis. RESULTS: A total of 40 patients were included, 15 (37.5%) of whom were classified as sarcopenic. Comparison between the sarcopenic and non-sarcopenia groups revealed homogeneity in terms of gender, age, BMI and pre-operative albumin levels. DGE occurred in 11 patients (27.5%) of whom 7 were sarcopenic. Significantly more sarcopenic patients suffered from DGE (7/15 vs 4/25, p = 0.042). Major postoperative complications and POPF occurred in 15 patients each (37.5%). Nevertheless, sarcopenia was not significantly associated with POPF or other complications. The presence of sarcopenia was found to have a significant relationship with the incidence of DGE (OR 4.594, 95% CI 1.052-20.057). DISCUSSION: Sarcopenia acted as an independent risk factor predicting DGE after PD but not for POPF or other major postoperative complications.

Structured, Protocol-Based Pulse-Oximetry Measurement Improves the Evaluation of Hypoxemic Patients at Hospital Admission.

BACKGROUND: Accurate pulse oximetry reading at hospital admission is of utmost importance, mainly for patients presenting with hypoxemia. Nevertheless, there is no accepted or evidence-based protocol for such structured measuring. OBJECTIVES: To devise and assess a structured protocol intended to increase the accuracy of pulse oximetry measurement at hospital admission. METHODS: The authors performed a prospective comparison of protocol-based pulse-oximetry measurement with non-protocol based readings in consecutive patients at hospital admission. They also calculated the relative percentage of improvement for each patient (before and after protocol implementation) as a fraction of the change in peripheral capillary oxygen saturation (SpO2) from 100%. RESULTS: A total of 460 patients were recruited during a 6 month period. Implementation of a structured measurement protocol significantly changed saturation values. The SpO2 values of 24.7% of all study participants increased after protocol implementation (ranging from 1% to 21% increase in SpO2 values). Among hypoxemic patients (initial SpO2 < 90%), protocol implementation had a greater impact on final SpO2 measurements, increasing their median SpO2 readings by 4% (3-8% interquartile range; P < 0.05). Among this study population, 50% of the cohort improved by 17% of their overall potential and 25% improved by 50% of their overall improvement potential. As for patients presenting with hypoxemia, the median improvement was 31% of their overall SpO2 potential. CONCLUSIONS: Structured, protocol based pulse-oximetry may improve measurement accuracy and reliability. The authors suggest that implementation of such protocols may improve the management of hypoxemic patients.

Perioperative complications of emergent and elective procedures in psychiatric patients.

BACKGROUND: Patients with psychiatric disorders have an increased risk for morbidity and mortality from other medical conditions. METHODS: Medical records of all the patients undergoing appendectomy (n = 2594) and laparoscopic cholecystectomy (n = 2874) from 2009 to 2014 in one hospital were reviewed. For each patient with a documented psychiatric disorder undergoing surgery, four controls were matched. RESULTS: The final sample of patients undergoing appendectomy included 96 patients, whereas those undergoing laparoscopic cholecystectomy included 260 patients. In the emergent scenario, psychiatric patients had longer time from symptom appearance to admission, longer hospitalization duration, and increased rate and severity of postoperative complications. In the elective scenario, psychiatric patients were shown to have more postoperative respiratory complications. CONCLUSIONS: Our results, together with the high prevalence of psychiatric disorders in the population, underscore the importance of screening for psychiatric disorders and their proper documentation in surgical patients.

The interaction between anti-Ro/SSA and anti-La/SSB autoantibodies and anti-infectious antibodies in a wide spectrum of auto-immune diseases: another angle of the autoimmune mosaic.

OBJECTIVES: The presence of anti-Ro/SSA and anti-La/SSB antibodies has been linked with autoimmunity in general and with several autoimmune diseases (AID) in particular. In the current study we evaluated these antibodies in a wide spectrum of AID as well as the links between them and anti-infectious antibodies. METHODS: We examined 2082 sera from patients with 16 different AID compared to 524 sera from geographically-matched healthy controls, for the presence and titres of anti-Ro/SSA and anti-La/SSB. All samples were also tested for a variety of anti-infectious agents' antibodies using the BioPlex 2200-immunoassay (Bio-Rad, USA). RESULTS: Anti-Ro/SSA was more prevalent, with significantly higher titre in 5 autoimmune diseases namely Sjögren's syndrome (SS), systemic lupus erythematosus (SLE), antiphospholipid syndrome (APS) both primary and APS linked to SLE, systemic sclerosis (SSc) and primary biliary cirrhosis (PBC). Anti-La/SSB was more prevalent with higher titers in SS, SLE, APS linked to SLE and PBC. Prevalence, but not titers, of both antibodies were higher also in polymyositis (PM). Additionally, we found a correlation between anti-Ro/SSA antibodies and antibodies of the IgM and IgG subtypes directed at cytomegalovirus as well as IgG-antibodies directed at Epstein-Barr virus (EBV) and toxoplasma (p<0.001). Anti-La/SSB antibodies correlated with the presence of IgG antibodies against EBV early antigen (p<0.001). CONCLUSIONS: In a large cohort of patients with autoimmune diseases we found an association between anti-Ro/SSA and anti-La/SSB antibodies and 6 autoimmune diseases, amongst which primary APS and PM. Additionally, we observed linkages between these autoantibodies and anti-infectious antibodies directed at Epstein-Barr virus, toxoplasma and cytomegalovirus. Our findings support the concept of interplay between infectious agents and autoimmunity, such as the plausibility of an infectious agent that trigger the immune system to produce specific antibodies which will later result in a unique group of AID.

Coexistent malignant conditions in rheumatoid arthritis - A population-based cross-sectional study.

OBJECTIVES: The aim of this study was to evaluate if association exist between rheumatoid arthritis and malignant diseases. METHODS: A cross-sectional study was conducted comparing rheumatoid arthritis patients with age and gender matched controls regarding the proportion of patients with comorbid malignant conditions. Chi-square tests and t-tests were used for univariate analysis. A logistic regression model was used for multivariate analysis. The study was performed utilising the medical database of Clalit Health Services. RESULTS: The study group included 11 782 rheumatoid arthritis patients and 57 973 controls. The total proportion of malignancies was significantly higher in the study group than in the control group (21.4% vs 11.2%; P<.001). The disease for which there was the strongest association among patients with rheumatoid arthritis was non-Hodgkin's lymphoma (1.1% vs 0.6%; P<.01). After multivariate analysis, lung cancer was not found to be significantly associated with rheumatoid arthritis. CONCLUSION: Rheumatoid arthritis is associated with several malignant disorders, in particular non-Hodgkin's lymphoma. Appropriate measures for non-Hodgkin's lymphoma screening in this patient population should be considered.

Risk of falling among hospitalized patients with high modified Morse scores could be further Stratified.

BACKGROUND: Falls during hospitalization harbor both clinical and financial outcomes. The modified Morse fall scale [MMFS] is widely used for an in-hospital risk-of-fall assessment. Nevertheless, the majority of patients at risk of falling, i.e. with high MMFS, do not fall. The aim of this study was to ascertain our study hypothesis that certain patients' characteristics (e.g. serum electrolytes, usage of a walking device etc.) could further stratify the risk of falls among hospitalized patients with MMFS. METHODS: This was a retrospective cohort analysis of adult patients hospitalized in Internal Medicine departments. RESULTS: The final cohort included 428 patients aged 76.8±14.0 years. All patients had high (9 or more) MMFS upon admission, and their mean MMFS was 16.2±6.1. A group of 139 (32.5%) patients who fell during their hospitalization was compared with a control group of 289 (67.5%) patients who did not fall. The fallers had higher MMFS, a higher prevalence of mild dependence, and a greater use of a cane or no walking device. Regression analysis showed the following patients' characteristics to be independently associated with an increased risk of falling: mild dependence (OR=3.99, 95% CI 1.97-8.08; p<0.0001), treatment by anti-epileptics (OR=3.9, 95% CI 1.36-11.18; p=0.011), treatment by hypoglycemic agents (OR=2.64, 95% CI 1.08-6.45; p= 0.033), and hypothyroidism (OR=3.66, 05%CI 1.62-8.30; p=0.002). In contrast to their role in the MMFS, the use of a walker or a wheelchair was found to decrease the risk of falling (OR=0.3, 95% CI 0.13-0.69; p=0.005 and OR=0.25, 95% CI 0.11-0.59; p= 0.002). CONCLUSIONS: Further risk stratification of hospitalized patients, already known to have a high MMFS, which would take into account the characteristics pointed out in this study, should be attained.

The Association Between Giant Cell Arteritis and Ischemic Heart Disease: A Population Based Cross-Sectional Study.

BACKGROUND: Patients with giant cell arteritis (GCA) suffer from inflammatory diseases often treated by large amounts of corticosteroids. Whether this inflammatory burden also carries an increased risk for cardiovascular morbidity, and especially ischemic heart disease, is not clearly established. OBJECTIVES: To clarify the linkage between GCA and ischemic heart disease. METHODS: In a cross-sectional study, we assessed the association between GCA and ischemic heart disease, adjusting for cardiovascular risk factors, among GCA patients and matched controls using the database of the largest healthcare provider in Israel. RESULTS: The study group was comprised of 5659 GCA patients and 28,261 age and gender matched controls. The proportion of ischemic heart disease was higher in the GCA group (27.5% vs. 12.5% among controls, odds ratio 2.65). Diabetes mellitus, hypertension, hyperlipidemia and smoking were also found to have higher concurrency in GCA. After stratifying for those cardiovascular co-morbidities using logistic regression, GCA remained independently associated with ischemic heart disease with an odds ratio of 1.247 (1.146-1.357 P < 0.001). CONCLUSIONS: GCA is associated with both cardiovascular risk factors and ischemic heart disease. Healthcare professionals should not overlook this aspect of the disease when managing GCA patients.

[THE INPUT OF MEASURING INFLIXIMAB LEVELS AND LEVELS OF ANTIBODIES TO INFLIXIMAB IN THE MANAGEMENT OF PATIENTS WITH RHEUMATIC DISEASES].

BACKGROUND: High levels of infliximab (IFX) directed antibodies (IFX-Ab) may result in significant reduction in IFX concentration and loss of drug efficacy. OBJECTIVES: To assess the input of measuring serum IFX levels and levels of IFX-Ab in the management of rheumatic diseases. METHODS: Serum levels of IFX and anti-IFX-Ab were measured by ELISA (IFX-Abs were also identified by anti-human lambda chain Ab) and correlated to patients (responders and nonresponders) disease activity scores. RESULTS: A total of 144 tests for IFX were performed in 91 patients (mean age 50.2 years and disease duration 9.9 years). Among responders (57 patients) levels (mean, median) of IFX were significantly higher than in non-responders (34 patients) (4.2 mcg/ml (2.3) versus 1.1 mcg/ml (0.45)); levels of IFX-Ab in responders were significantly lower than in non-responders (4.59 mcg/ml (1.0) versus 13.1 (6.1)). High IFX-Ab levels predicted IFX discontinuation in 8.8% of responders and 55.9% among non-responders. In non-responders with low IFX levels and low IFX-Ab, the shortening of re-treatment intervals lead to significant improvement. In about 28% of patients, results of blood tests influenced treatment decisions. CONCLUSIONS: Assessment of immunogenicity of anti-TNF monoclonal antibodies proved useful information for guiding the therapy in rheumatic diseases with suboptimal clinical response. Patients with low IFX levels and low levels of IFXAb may benefit from increasing the drug dose or decreasing of re-treatment intervals. In patients with negligible serum levels of IFX and high levels of IFX-Ab, the therapy should be switched to another biological agent, probably with a different mechanism of action.