A short history of the discovery of the erythrocyte sedimentation rate

A machine learning approach for assessing acute infection by erythrocyte sedimentation rate (ESR) kinetics

BACKGROUND

The erythrocyte sedimentation rate (ESR) is a traditional marker of inflammation, valued for its simplicity and low cost but limited by unsatisfactory specificity and sensitivity. This study evaluated the equivalence of ESR measurements obtained from three automated analyzers compared to the Westergren method. Furthermore, various machine learning (ML) techniques were employed to assess the usefulness of early sedimentation kinetics in inflammatory disease classification.

METHODS

A total of 346 blood samples from control, rheumatological, oncological, and sepsis/acute inflammatory status groups were analyzed. ESR was measured using TEST 1 (Alifax Spa, Padua, Italy), VESMATIC 5 (Diesse Diagnostica Senese Spa, Siena, Italy), CUBE 30 TOUCH (Diesse Diagnostica Senese Spa, Siena, Italy) analyzers, and the Westergren method. Early sedimentation rate kinetics (within 20 min) obtained with the CUBE 30 TOUCH were assessed. ML models [Gradient Boosting Machine (GBM), Support Vector Machine (SVM), Naïve Bayes (NB), Neural Networks (NN) and logistic regression (LR)] in discriminating groups were trained and validated using ESR, sedimentation slopes, and clinical data. A second validation cohort of control and sepsis samples was used to validate LR models.

RESULTS

Automated methods showed good agreement with Westergren's results. Multivariate analyses identified significant associations between ESR values (measured by CUBE 30 TOUCH) and age (p = 0.025), gender (p < 0.001), and, overall, with samples' group (p < 0.001). Sedimentation rate slopes differed significantly across groups, particularly between 12 and 20 min, with sepsis cases showing distinct patterns. ML models achieved moderate accuracy, with GBM performing best (AUC 0.80). LR for sepsis classification in the validation cohort achieved an AUC of 0.884, with high sensitivity (96.9 %) and specificity (74.2 %). In the second validation cohort, LR outperformed prior results, reaching an AUC of 0.991 (95 % CI: 0.973-1.000), with 95.2 % sensitivity and 100 %.

CONCLUSIONS

Current automated technologies for ESR measurement well agree with the reference method and provide robust results for evaluating systemic infections. The novelty of this study lies in connecting ESR sedimentation kinetics to disease states, particularly for identifying sepsis/acute inflammatory status. Future studies with larger datasets are needed to validate these approaches and guide clinical application.

Extremely elevated erythrocyte sedimentation rates: Associations with patients' diagnoses and clinical characteristics

INTRODUCTION

The aim of the study was to assess the etiological distribution of patients with an erythrocyte sedimentation rate (ESR) over 100 mm/hour and to evaluate differences in demographic, comorbidity, laboratory characteristics, and clinical outcomes.

METHODS

This retrospective observational clinical study included patients aged 18 years and older who were admitted to the internal medicine inpatient clinic between May 1, 2015 and June 1, 2021 and had ESR values above 100 mm/h. Demographic data, comorbidities, laboratory parameters, imaging studies, histopathological findings, microbiological and serological data, along with in-hospital and post-discharge mortality, were collected from the hospital's electronic database. Two independent clinicians evaluated the data to identify diagnoses associated with elevated ESR. Patients were divided into six categories based on the most likely diagnosis.

RESULTS

The study included 441 patients, 52.6% of whom were female, and the mean age was 72.6 years. The etiological distribution was as follows: infectious diseases (34%), malignancies (31.5%), undiagnosed cases (15.9%), renal diseases (9.8%), other causes (5%), and rheumatologic diseases (3.8%). Etiological distributions did not differ by gender, age, or ESR ranges. The in-hospital mortality rate was 3.6%, and the overall mortality rate from hospitalization to the data collection date was 64.4%. Mortality was higher in patients with malignancies (81.3%) compared to other etiologies (p<0.001). Patients who died had higher mean age, ferritin levels, having diabetes mellitus, heart failure, or malignancy, and lower hemoglobin and lymphocyte levels compared to survivors (p<0.05 for all).

CONCLUSION

Most patients with an ESR over 100 mm/hour had significant underlying medical conditions, with infectious diseases and malignancies comprising two-thirds of the cases.

The Erythrocyte Sedimentation Rate (ESR) in Veterinary Medicine: A Focused Review in Dogs and Cats

The erythrocyte sedimentation rate (ESR) measures the rate at which erythrocytes aggregate and sediment in a fixed time in an anticoagulated blood tube and is expressed as a speed (mm/h). The ESR is still widely used in human medicine mainly as a modified or alternate method to the original Westergren. In veterinary medicine, it was employed in the 1940s-1960s after which it was gradually abandoned or rarely employed. More papers using the Westergren method have been published in dogs rather than in cats. In recent years, the test has regained importance. This narrative review describes the principle of ESR, which is related to the increase in a few acute response proteins such as fibrinogen, immunoglobulin M, and α2-macroglobulin which act to aggregate RBCs. Reference intervals were established for dogs and cats for the original and modified Westergren method. The ESR is mainly used to detect inflammatory conditions derived from infection, urinary or orthopedic disorders, and also miscellaneous diseases. The application of the modified ESR is supported by appropriate reference intervals; however, further studies are needed to assess the influence of age, sex, and breed both for dogs and cats.

Challenges of preanalytical variables in erythrocyte sedimentation rate: a CUBE 30 touch evaluation

The erythrocyte sedimentation rate (ESR) is a widely used diagnostic test, influenced by all physiological and pathological conditions that can bias blood rheology by interfering factors. This study aimed to evaluate the performance of the CUBE 30 touch ESR analyzer in samples with preanalytical variables, as lipemia, hemolysis, and icterus or in presence of fibrinogen., Moreover we focused to define the maximum time limits to ensure a reliable ESR measure. Accuracy, intra-run and inter-run precision, and stability studies were performed. Moreover, hemolytic, jaundiced, lipemic samples and fibrinogen sensitivity were analyzed for interference study. Statistical analyses were performed. CUBE 30 touch and Westergren method comparison showed no statistical differences (Spearman Coefficient, R2=0,95). In the intra-run precision, the CV% mean obtained on samples with normal ESR level was 8,9%; with middle ESR level was 5,9% and with high ESR level the CV% was 4,3%. Inter-run precision test showed CV% of for single samples and overall samples in the range (12,3% for normal level and 4,8% for abnormal level). The samples stored at 4 °C showed good stability up to 3 h from collecting time. ESR samples showing lipemia, hemolysis or jaundice showed good correlations with the gold standard method (R2 0,901, 0,940, 0,911; p < 0,0001), however, Westergren tests were more sensitive than CUBE 30 touch to fibrinogen additions. The high comparability with the Westergren method, both in normal and interfering samples, and the good precision, support the usefulness of CUBE 30 touch in the clinical routine laboratory.

Study of erythrocyte sedimentation in human blood through the photoacoustic signals analysis

Introduction

In this study, we utilized the pulsed photoacoustic (PA) technique to analyze globular sedimentation in whole human blood, with a focus on distinguishing between healthy individuals and those with hemolytic anemia.

Methods

Blood samples were collected from both healthy individuals (women and men) and those with hemolytic anemia, and temporal and spectral parameters of PA signals were employed for analysis.

Results

Significant differences (p < 0.05) were observed in PA metrics between the two groups. The proposed spectral analysis allowed significant differentiation within a 25-minute measurement window. Anemic blood samples exhibited higher erythrocyte sedimentation rate (ESR) values, indicating increased erythrocyte aggregation.

Discussion

This study underscores the potential of PA signal analysis in ESR assessment as an efficient method for distinguishing between healthy and anemic blood, surpassing traditional approaches. It represents a promising contribution to the development of precise and sensitive techniques for analyzing human blood samples in clinical settings.

Increased Erythrocyte Sedimentation Rate in Dogs: Frequency in Routine Clinical Practice and Association with Hematological Changes

(1) Background: the erythrocyte sedimentation rate (ESR) has been reported to increase in some infectious or inflammatory diseases in dogs, but no information on the frequency of increases in a routine clinical setting exists. The aim of this study was to assess the frequency of an increased ESR in dogs and to investigate its possible association with hematologic changes; (2) Methods: A total of 295 EDTA blood samples were randomly selected from the routine caseload of the Veterinary Teaching Hospital. Samples were grouped in controls and in pathologic groups based on the clinical presentation. A routine hemogram was performed, then the ESR was measured using the instrument MINI-PET; (3) Results: compared with controls, the ESR was significantly higher in all the pathologic groups, except for the hematological disorders group. The highest ESR was found in samples from dogs with chronic kidney disease or inflammation, followed by those from dogs with mild chronic disorders, severe/acute diseases, tumors and urinary disorders. The ESR negatively correlated with hematocrit and positively with neutrophil counts. (4) Conclusions: The ESR increases more frequently in dogs with clinically evident inflammation or CKD, but also in several other conditions, likely as a consequence of anemia and acute phase response.

Validation of the New MINI-CUBE for Clinic Determination of Erythrocyte Sedimentation Rate

Background

Erythrocyte sedimentation rate (ESR) indirectly measures blood fibrinogen, and it is altered by all those pathological conditions that modify the aggregation of red blood cells. The international guidelines by the International Council for Standardization in Hematology (ICSH) define the Westergren method as the gold standard for ESR, although it is completely operator-dependent, time-consuming, and requires a patient's blood consumption. Therefore, the validation of new ESR analyzers is needed. The aim of this study is the validation of a new automated ESR analyzer, MINI-CUBE (DIESSE, Diagnostica Senese, Italy).

Methods

The samples (n = 270) were collected at the University Hospital of the University of Rome Tor Vergata. A comparison between the automated instrument and the gold standard was performed. Statistical analyses were processed by MedCalc software.

Results

The comparison analysis performed on the overall samples reported a good agreement, showing a Spearman rank correlation coefficient of 0.94 (P < 0.001), compared to the Westergren test. The Bland-Altman analysis showed a mean bias of 1.5 (maximum (max.):19.6; minimum (min.): -16.6). Inter-run (level 1 coefficient of variation (CV): 4.9%; level 2 CV: 0.8%), intra-run (level 1 CV: 21.1%; level 2 CV: 3.2%), and inter-instrument (level 1 CV: 27.1%; level 2 CV: 5.6%) precision were also assessed. The hematocrit value did not interfere with the analysis: Spearman rank correlation coefficient of 0.929 (P < 0.001); mean bias of 1.3 (max.:18.3; min.: -15.6).

Conclusions

Overall results from MINI-CUBE asserted a good correlation rate with the gold standard, and it could be considered an accurate, and objective alternative for the Westergren test.

Extremely high erythrocyte sedimentation rate revisited in rheumatic diseases: a singlecenter experience

BACKGROUND

The objectives were to define the distribution of rheumatic diseases in patients with erythrocyte sedimentation rate (ESR) ≥ 100 mm/h and to find variables that can differentiate main study groups from others.

METHODS

Charts of patients admitted with ESR ≥ 100 mm/h between 2015 and 2020 were reviewed. Patients were divided into four diagnostic groups based on etiology: infection (without a rheumatic diagnosis), oncologic (without a rheumatic diagnosis), rheumatic, and no definitive diagnosis. Patients with the rheumatic diagnosis were divided into three main study groups: those who had been recently diagnosed with a rheumatic disease, those who had a flare-up of the rheumatic disease, and those who had an infection in the course of the rheumatic disease. Appropriate statistical tests and decision-tree analysis by R and ROC curve were applied. p < 0.05 was considered statistically significant.

RESULTS

A total of 2442 patients (311 (12.7%) with rheumatic disorders) were identified. Eightysix (27.7%) patients had newly diagnosed rheumatic disease (41; 47.7% with vasculitis); 111 (35.7%) had rheumatic disease flare-up (92; 82.9% with inflammatory arthritis); and 114 (36.6%) had coexisting infection (61; 53.5% inflammatory arthritis). Irrespective of the study group, the most commonly encountered diseases were rheumatoid arthritis and spondyloarthritis. Serum albumin levels (2.78 mg/dL) and platelet count (290/mm6 ) were valuable to discriminate disease flare-up and coexisting infection; moreover, high ferritin levels were accounted for adult-onset Still disease among patients with newly diagnosed rheumatic diseases.

DISCUSSION

Extremely high ESR is still a valuable clinical parameter, and rheumatic causes are significant besides malignancy and infections. Albumin, thrombocyte count, and ferritin are other tests that clinicians should consider when caring for a patient with ESR ≥ 100 mm/h who has rheumatic disease.

Erythrocyte sedimentation rate measurements using MIX-RATE® X20 and VISION A automated analyzers: Method validation and comparison study

BACKGROUND

The Westergren method for erythrocyte sedimentation rate (ESR) measurement has a few drawbacks such as being a time-consuming process, poses a risk of biohazard exposure and requires high sample volume. Recent alternative methods and analyzers were developed to overcome those limitations. In this study, we validated two automated ESR analyzers, MIX-RATE® X20 and VISION A, and assessed their analytical performance against the Westergren method.

METHODS

The analyzers were validated for inter-run and intra-run precision. Hemolysis interference and sensitivity to fibrinogen were also analysed. Analytical performance was performed using 177 patient samples spanning low (<40 mm/h), medium (40-80 mm/h), and high (>80 mm/h) ESR ranges. Method agreement and bias against the Westergren method were calculated.

RESULTS

The highest intra-run imprecision was seen in the low ESR range for both analyzers. They showed very high agreement with the Westergren method assessed by Spearmen rank correlation coefficient analysis, r = 1.000, p < .0001 for both analyzers. Bland-Altman analysis yielded overall insignificant mean biases for all comparisons. However, systematic positive and negative bias were observed at medium and high ESR levels analysed by MIX-RATE® X20 while negative bias was evidenced in the high ESR level measured by VISION A.

CONCLUSIONS

Overall, results from both automated ESR analyzers showed comparable analytical performance with the Westergren method especially for low ESR levels. However, both positive and negative systematic bias were documented in the high levels. Thus, for clinical use, it must be assessed whether these biases could affect the cut-off for significant clinical values.

The Canine Erythrocyte Sedimentation Rate (ESR): Evaluation of a Point-of-Care Testing Device (MINIPET DIESSE)

The erythrocyte sedimentation rate (ESR) in canine medicine has been replaced by the evaluation of a few sensitive markers of the acute-phase proteins. The aim of the study was to evaluate the ESR using a point-of-care (MINIPET, DIESSE Diagnostica Senese S.p.A.) device (ESR-MP) and to compare the results with the gold standard Westergren method (ESR-W) in dogs. One hundred and nineteen K3-EDTA blood samples for complete blood count were randomly selected and assayed for ESR. The reference interval (RI) was established using the percentile method. The coefficient of variation (CV) in intra-assay and interassay precision of ESR-MP was calculated. The analytical sensitivity (Se), specificity (Sp), positive predictive values (PPVs), and negative predictive values (NPVs) were calculated. Agreement between ESR-MP and ESR-W was assessed with Pearson correlation coefficient (r), Cohen concordance test (K), Passing-Bablok regression, and Bland–Altman plots. Ten canine samples (8.4%) were ruled out because of flag-error by the MINIPET instrument (4.2%) or because they showed the diphasic pattern in ESR-W (4.2%). The canine RI of ESR-MP was 0–10 mm/h. Precision was excellent in intra-assay (CV = 0.02) and interassay (CV = 0.32). The analytical characteristics of ESR-MP in nonanemic samples were as follows: Se = 0.82, Sp = 0.95, PPV = 0.82, and NPV = 0.95. The accuracy of ESR-MP was better than ESR-W in nonanemic samples (r = 0.87; K = 0.77) and lower in anemic subjects (Hct <37%) (r = 0.76; K = 0.69). The Passing-Bablok regression showed the presence of systematic error and the absence of proportional error only in nonanemic blood samples. The Bland–Altman plots gave negative average values due to the difference in RIs and an agreement in both ESRs. The ESR-MP results can be obtained with the same K3-EDTA tubes used for the blood count, in shortcut time, and at reduced costs using the MINIPET device. These investigations highlight that ESR-MP could be useful in canine clinical settings.

Factors influencing erythrocyte sedimentation rate in adults: New evidence for an old test

The erythrocyte sedimentation rate (ESR) is a routine test for inflammation. Few studies have investigated the potential influence of lifestyle factors and common metabolic abnormalities on the ESR. This study investigates the influence of demographic factors, alcohol consumption, smoking, physical activity, obesity, and metabolic syndrome on the ESR in adults.This cross-sectional study covered 1472 individuals (44.5% males; age range, 18-91 years) randomly selected from the population of a Spanish municipality. The ESR was measured using a standardized method. We assessed habitual alcohol consumption in standard drinking units, along with tobacco smoking, regular physical exercise (by questionnaire), body mass index, and variables defining metabolic syndrome. Multivariate analyses were performed, including mean corpuscular volume and hemoglobin concentration in the models.The ESR was higher in females than in males, and increased steadily with age. Median ESR of females was 2-fold higher than that of males, and median ESR of individuals aged >65 years was 2-fold higher than that of individuals in the youngest category (ages 18-35 years). Body mass index, presence of metabolic syndrome, and smoking were independently and positively associated with higher ESR values. Light alcohol drinkers and individuals with high regular physical activity displayed lower ESR values than did alcohol abstainers and individuals with low physical activity, respectively.ESR varies greatly with age and sex, and corresponding reference values are proposed. Lifestyle factors (physical activity, smoking, and alcohol consumption) and common metabolic abnormalities (obesity and related metabolic syndrome) may also influence ESR values.

Differences in erythrocyte sedimentation rates using a modified Westergren method and an alternate method

INTRODUCTION

Worldwide laboratories have adopted the use of modified or alternate methods for measurement of the erythrocyte sedimentation rate (ESR). The iSED from Alcor Scientific is a novel, alternate ESR method based on photometric aggregometry which offers improved operator safety and reduced analysis time. This study evaluated the diagnostic utility of the iSED in a South African patient population with a range of inflammatory disorders.

METHODS

We compared the iSED with the predicate modified Westergren method (StaRRsed, Mechatronics, Zwaag, the Netherlands) measured at 60 minutes. Analysis was performed on K₂ EDTA samples at three ESR measurement ranges (<20, 20-80 and >80 mm/h) in 120 pediatric and adult inpatients and outpatients over a 2-week period. Precision, stability, and carryover were performed in accordance with the revised International Council for Standardisation in Haematology guidelines.

RESULTS

The iSED demonstrated acceptable imprecision with minimal carryover (2.86%). The correlation coefficients at the 3 ESR measurement ranges were r = 0.58, r = 0.71, and r = 0.56, respectively. The y-intercepts were -10.74 (CI -29.17 to 7.69), -5.95 (CI -18.60 to 6.69) and 246.05 (CI 591.42-99.31). This indicated a difference of a constant nature with an overall mean difference of 7.99 mm/h (CI 5.87-10.13) (P < 0.001). iSED ESR measurements were stable up to 24 hours when stored at room temperature or at 4-8°C.

CONCLUSION

This study demonstrated differences in ESR results, predominantly at extremes of the analytical range, using an alternate method. Careful consideration and performance monitoring of these novel methods are advised.

ICSH recommendations for modified and alternate methods measuring the erythrocyte sedimentation rate

INTRODUCTION

The gold standard for the determination of the erythrocyte sedimentation rate (ESR) is the Westergren method. Other methods to measure the ESR have become available. They range from modest modifications of the Westergren method to very different methodologies. The ICSH therefore established a Working Group to investigate these new approaches and compile recommendations for their validation and verification.

METHODS

A panel of six experts in laboratory hematology examined the peer-reviewed literature and EQA surveys from over 6000 laboratories on four continents performing ESR testing. This information was used to create lists of ESR instrument manufacturers and their methods.

RESULTS

Only 28% of laboratories surveyed used the unmodified Westergren method, while 72% of sites used modified or alternate methods. Results obtained with the new instruments could differ from results obtained with the Westergren method by up to 142%. Different non-Westergren methods showed differences from each other of up to 42%. The new methods were often significantly faster, safer, and less labor-intensive. They reduced costs and often used standard EDTA tubes, eliminating the need for a dedicated ESR tube.

CONCLUSION

Based on the consensus of the Working Group, recommendations for manufacturers for the validation of new ESR methods were developed. In addition, a list of recommendations for laboratories that are moving to modified or alternate methods was compiled, addressing instrument performance verification and communications of results to clinical users.

Selected inflammatory markers in the diagnosis and monitoring of infections in children treated for hematological malignancies

Infections in children treated for hematological malignancies pose a direct threat to life and are one of the most common causes of treatment failure in this group of patients. Unequivocal diagnosis at the early stages of infection together with an appropriate and timely treatment may be often difficult due to poor manifestation and nonspecific clinical symptoms of the infection progress. Inflammatory markers make a useful diagnostic tool for this purpose. They significantly help to diagnose, monitor, stratify and predict the outcome in severe infections. This article describes selected biomarkers, both those commonly used in clinical practice, such as erythrocyte sedimentation rate, C-reactive protein, procalcitonin as well as less common like IL-6, IL-8 and moreover one promising novel marker – pentraxin 3. The authors emphasize their diagnostic value, clinical usefulness and significance in the treatment efficacy monitoring.

Vascular endothelium: a vulnerable transit zone for merciless sodium

In humans, when plasma sodium concentration rises slightly beyond 140 mM, vascular endothelium sharply stiffens and nitric oxide release declines. In search of a vascular sodium sensor, the endothelial glycocalyx was identified as being a negatively charged biopolymer capable of selectively buffering sodium ions. Sodium excess damages the glycocalyx and renders vascular endothelium increasingly permeable for sodium. In the long term, sodium accumulates in the interstitium and gradually damages the organism. It was discovered that circulating red blood cells (RBC) 'report' surface properties of the vascular endothelium. To some extent, the RBC glycocalyx mirrors the endothelial glycocalyx. A poor (charge-deprived) endothelial glycocalyx causes a poor RBC glycocalyx and vice versa. This observation led to the assumption that the current state of an individual's vascular endothelium in terms of electrical surface charges and sodium-buffering capabilities could be read simply from a blood sample. Recently, a so-called salt blood test was introduced that quantifies the RBC sodium buffer capacity and thus characterizes the endothelial function. The arguments are outlined in this article spanning a bridge from cellular nano-mechanics to clinical application.

Determination of erythrocyte sodium sensitivity in man

Sodium buffer capacity of vascular endothelium depends on an endothelial glycocalyx rich in negatively charged heparan sulfate. It has been shown recently that after the mechanical interaction of blood with heparan sulfate-depleted endothelium, erythrocytes also lose this glycocalyx constituent. This observation led to the conclusion that the vascular sodium buffer capacity of an individual could be derived from a blood sample. A test system (salt blood test (SBT)) was developed based upon the sodium-dependent erythrocyte zeta potential. Erythrocyte sedimentation velocity was measured in isosmotic, biopolymer-supplemented electrolyte solutions of different sodium concentrations. Erythrocyte sodium sensitivity (ESS), inversely related to erythrocyte sodium buffer capacity, was expressed as the ratio of the erythrocyte sedimentation velocities of 150 mM over 125 mM Na⁺ solutions (ESS = Na⁺₁₅₀/Na⁺₁₂₅). In 61 healthy individuals (mean age, 23 ± 0.5 years), ESS ranged between 2 and 8. The mean value was 4.3 ± 0.19. The frequency distribution shows two peaks, one at about 3 and another one at about 5. To test whether ESS reflects changes of the endothelial glycocalyx, a cultured endothelial monolayer was exposed for 3 hours to a rhythmically moving blood layer (drag force experiment). When applying this procedure, we found that ESS was reduced by about 21 % when the endothelium was pretreated for 4 days with the glycocalyx protective agent WS 1442. In conclusion, the SBT could possibly serve as an in vitro test system for the evaluation of erythrocyte/vascular salt sensitivity allowing follow-up measurements in the prevention and treatment of vascular dysfunctions.