Edmund Biernacki (1866-1911): Discoverer of the erythrocyte sedimentation rate. On the 100th anniversary of his death

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.

Method Comparison of Erythrocyte Sedimentation Rate Automated Systems, the VES-MATIC 5 (DIESSE) and Test 1 (ALIFAX), with the Reference Method in Routine Practice

Background: The erythrocyte sedimentation rate (ESR) is a routine and aspecific test that is still widely used. The reference-manual method for ESR determination is the Westergren method. The VES-MATIC 5 is a novel, fully automated, and closed system based on a modified Westergren method. This study conceived the aim of comparing two ESR analytical analysers, Test 1 and the VES-MATIC 5, with the reference method in routine practice. Methods: This study included 264 randomly analysed samples. A comparison between the two methods and Westergren was performed, and they were evaluated for inter-run and intra-run precision. In addition, we investigated possible interferences and different sensitivities to conventional analytes. Results: The comparison of methods by Passing-Bablok analysis provided a good agreement for both systems, with a better correlation for VES-MATIC 5 (p = 0.96) than Test 1 (p = 0.93), and sensitivity studies did not show any significant influence. Conclusions: The VES-MATIC 5 analyser demonstrated excellent comparability with the reference method, and it had better performance than Test 1. It can be employed in routine practice, bringing advantages such as a reduction in the probability of human error compared to the manual method, as well as an increase in operator safety and environmental protection.

Early stage of erythrocyte sedimentation rate test: Fracture of a high-volume-fraction gel

Erythrocyte sedimentation rate (ESR) is a clinical parameter used as a nonspecific marker for inflammation, and recent studies have shown that it is linked to the collapse of the gel formed by red blood cells (RBCs) at physiological hematocrits (i.e. RBC volume fraction). Previous research has suggested that the observation of a slower initial dynamics is related to the formation of fractures in the gel. Moreover, RBC gels present specific properties due to the anisotropic shape and flexibility of the RBCs. Namely, the onset of the collapse is reached earlier and the settling velocity of the gel increases with increasing attraction between the RBCs, while the gel of spherical particles shows the opposite trend. Here, we report experimental observations of the gel structure during the onset of the collapse. We suggest an equation modeling this initial process as fracturing of the gel. We demonstrate that this equation provides a model for the motion of the interface between blood plasma and the RBC gel, along the whole time span. We also observe that the increase in the attraction between the RBCs modifies the density of fractures in the gel, which explains why the gel displays an earlier onset when the aggregation energy between the RBCs increases. Our work uncovers the detailed physical mechanism underlying the ESR and provides insights into the fracture dynamics of an RBC gel. These results can improve the accuracy of clinical measurements.

Clinical application of a new method for determination of the erythrocyte sedimentation rate using the BC-720 automated hematology analyzer

BACKGROUND

The erythrocyte sedimentation rate (ESR) is a nonspecific inflammatory indicator and is widely used in clinical diagnosis. Westergren is the gold standard method recommended by the International Committee for Standardization of Hematology (ICSH), but it is time-consuming and inconvenient and has biosafety risks. A new alternate method for ESR (Easy-W ESR) measurement was designed and integrated into the Mindray BC-720 series automated hematology analyzer to meet the clinical needs of hematology laboratories for efficiency, safety, and automation. In this study, the performance of the new ESR method was evaluated based on the ICSH recommendations on modified and alternate ESR methods.

METHODS

Methodological comparisons using the BC-720 analyzer, TEST 1, and the Westergren method were performed to assess repeatability, carryover, sample stability, reference range validation, factors influencing the ESR, and clinical applicability in rheumatology and orthopedics.

RESULTS

The correlation between the BC-720 analyzer and the Westergren method was good (Y = 2.082 + 0.9869X, r = 0.9657, P > 0.0001, n = 342), carryover was <1%, the repeatability standard deviation was ≤1 mm/h, and the coefficient of variation (CV) was ≤5%. The reference range meets the manufacturer's claim. For rheumatology patients, the BC-720 analyzer showed a good correlation with the Westergren method (Y = 1.021X-1.941, r = 0.9467, n = 149). For orthopedic patients, the BC-720 analyzer also showed a good correlation with the Westergren method (Y = 1.037X + 0.981, r = 0.978, n = 97).

CONCLUSION

This study verified the clinical and analytical performance of the new ESR method, indicating that the results are very similar to those obtained using the Westergren method.

The VES-Matic 5 system: performance of a novel instrument for measuring erythrocyte sedimentation rate

OBJECTIVES

The VES-Matic 5 is an automated analyzer that assesses erythrocyte sedimentation rate based on a modified Westergren sedimentation technique. Instrument performance was established by addressing the recommendations of the International Council for Standardization in Haematology.

METHODS

Comparison against the reference Westergren method was performed for all samples, and further for the low, middle, and upper third of the analytical range. Intra-run precision, inter-run precision, and interference studies were further assessed. This study included the evaluation of reference ranges.

RESULTS

The comparison of methods by Passing-Bablok analysis has shown a good agreement without systematic or proportional differences. The regression equation was y=-0.646 + 0.979x. The mean bias of -0.542 was obtained by Bland-Altman analysis and the upper limit of 8.03 with the lower limit of -9.11 can be considered clinically acceptable. Intra-run and inter-run precision were good for each parameter and interference studies did not show any significant bias with exception of anemia samples, which showed a proportional difference when comparing high erythrocyte sedimentation rate values. Using the local adult reference population, we verified the reference ranges in comparison to those available in the literature, and according to the Clinical Laboratory Standards Institute (CLSI) EP28-A3C document. We determined the upper limit partitioned by gender and the following age groups: from 18 to 50, from 50 to 70, and over 70.

CONCLUSIONS

The VES-Matic 5 analyzer presented good comparability with the reference method. As there are commercial quality control and suitable external quality assessment (EQA) material and programs, the VES-Matic 5 can be employed appropriately for routine purposes.

Novel characteristics of soluble fibrin: hypercoagulability and acceleration of blood sedimentation rate mediated by its generation of erythrocyte-linked fibers

Soluble fibrin (SF) in blood consists of monomers lacking both fibrinopeptides A with a minor population in multimeric clusters. It is a substantial component of isolated fibrinogen (fg), which spontaneously self-assembles into protofibrils progressing to fibers at sub-physiologic temperatures, a process enhanced by adsorption to hydrophobic and some metal surfaces. Comparisons of SF-rich (FR) and SF-depleted (FD) fg isolates disclosed distinct molecular imprints of each via an adsorption/desorption procedure using gold surfaced silica microplates. Accelerated plasminogen activator-induced lysis and decreased stiffness (G′) of thrombin-induced FR fg clots were revealed by thomboelastography. Erythrocyte sedimentation (ESR) in afibrinogenemic plasma (Hematocrit 25–33%) was accelerated by FR fg nearly threefold that of FD fg. Stained smears disclosed frequent rouleaux formations and fibers linking stacked erythrocytes in contrast to no rouleaux by FD fg. Rouleaux formations were more pronounced at 4 °C than at ambient temperatures and at fiber-membrane contacts displayed irregular, knobby membrane contours. One of several FR fg isolates also displayed incomplete fiber networks in cell-free areas. What is more, pre-mixing FR fg with each of three monoclonal IgG anti-fg antibodies at 1.5 mol/mol fg, that inhibited fibrin polymerization, prevented rouleaux formation save occasional 2–4 erythrocyte aggregates. We conclude that spontaneously generated SF fibers bound to erythrocytes forming intercellular links culminating in rouleaux formation and ensuing ESR acceleration which in clinical settings reflects hypercoagulability. Also, the results can explain the reported fg binding to erythrocytes via ligands such as CD47, stable in vivo RBC aggregates in capillaries, and red areas of pathologic thrombi.

Erythrocyte Sedimentation: Collapse of a High-Volume-Fraction Soft-Particle Gel

The erythrocyte sedimentation rate is one of the oldest medical diagnostic methods whose physical mechanisms remain debatable today. Using both light microscopy and mesoscale cell-level simulations, we show that erythrocytes form a soft-particle gel. Furthermore, the high volume fraction of erythrocytes, their deformability, and weak attraction lead to unusual properties of this gel. A theoretical model for the gravitational collapse is developed, whose predictions are in agreement with detailed macroscopic measurements of the interface velocity.

Rapid determination of erythrocyte sedimentation rate (ESR) by an electrically driven blood droplet biosensor

In healthcare practice, the sedimentation rate of red blood cells (erythrocytes) is a widely used clinical parameter for screening of several ailments such as stroke, infectious diseases, and malignancy. In a traditional pathological setting, the total time taken for evaluating this parameter varies typically from 1 to 2 h. Furthermore, the volume of human blood to be drawn for each test, following a gold standard laboratory technique (alternatively known as the Westergren method), varies from 4 to 5 ml. Circumventing the above constraints, here we propose a rapid (∼1 min) and highly energy efficient method for the simultaneous determination of hematocrit and erythrocyte sedimentation rate (ESR) on a microfluidic chip, deploying electrically driven spreading of a tiny drop of blood sample (∼8 μl). Our unique approach estimates these parameters by correlating the same with the time taken by the droplet to spread over a given radius, reproducing the results from more elaborate laboratory settings to a satisfactory extent. Our novel methodology is equally applicable for determining higher ranges of ESR such as high concentration of bilirubin and samples corresponding to patients with anemia and patients with some severe inflammation. Furthermore, the minimal fabrication steps involved in the process, along with the rapidity and inexpensiveness of the test, render the suitability of the strategy in extreme point-of-care settings.

Sesquicentennial of the birth of Edmund Faustinus Biernacki, a discoverer of the erythrocyte sedimentation rate

Edmund Faustinus Biernacki (1866-1911) was a Polish physician and philosopher of medicine. He described erythrocyte sedimentation, designed equipment to measure the erythrocyte sedimentation rate, and applied it to clinical practice. His contribution to the development of one of the most commonly used medical laboratory tests is forgotten, and the test is attributed to other scientists.

A portable microfluidic system for rapid measurement of the erythrocyte sedimentation rate

The erythrocyte sedimentation rate (ESR) is a frequently used 30 min or 60 min clinical test for screening of several inflammatory conditions, infections, trauma, and malignant diseases, as well as non-inflammatory conditions including prostate cancer and stroke. Erythrocyte aggregation (EA) is a physiological process where erythrocytes form face-to-face linear structures, called rouleaux, at stasis or low shear rates. In this work, we proposed a method for ESR measurement from EA. We developed a microfluidic opto-electro-mechanical system, using which we experimentally showed a significant correlation (R² = 0.86) between ESR and EA. The microfluidic system was shown to measure ESR from EA using fingerprick blood in 2 min. 40 μl of whole blood is filled in a disposable polycarbonate cartridge which is illuminated with a near infrared emitting diode. Erythrocytes were disaggregated under the effect of a mechanical shear force using a solenoid pinch valve. Following complete disaggregation, transmitted light through the cartridge was measured using a photodetector for 1.5 min. The intensity level is at its lowest at complete disaggregation and highest at complete aggregation. We calculated ESR from the transmitted signal profile. We also developed another microfluidic cartridge specifically for monitoring the EA process in real-time during ESR measurement. The presented system is suitable for ultrafast, low-cost, and low-sample volume measurement of ESR at the point-of-care.

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.

Markers of intestinal inflammation for the diagnosis of infectious gastroenteritis

Infectious diarrhea is a major cause of morbidity. A rapid and inexpensive assay for the diagnosis of infectious gastroenteritis would expedite appropriate therapy and prevent unnecessary and potentially invasive testing. This article summarizes assays for the diagnosis of infectious gastroenteritis based on the host response to bacterial, viral, or parasitic infection. This includes both systemic biomarkers (such as C-reactive protein, erythrocyte sedimentation rate, and serum cytokines) and fecal biomarkers (such as lactoferrin, fecal leukocyte analysis, and calprotectin). Although some of these assays have value as adjunct diagnostics, they lack sensitivity and specificity as stand-alone tests in this setting.