Red blood cell (RBC) aggregate to form two- and three-dimensional structures when suspended in aqueous solutions containing large plasma proteins or polymers; this aggregation is reversible and shear dependent (i.e., dispersed at high shear and reformed at low or stasis). The extent of aggregation is the main determinant of low shear blood viscosity, thus predicting an inverse relationship between aggregation and in vivo blood flow. However, the effects of aggregation on hemodynamic mechanisms (e.g., plasma skimming, Fahraeus Effect, microvascular hematocrit) may promote rather than impede vascular blood flow. The impact of enhanced RBC aggregation on endothelial function and hemostatic mechanisms adds further complexity, thereby requiring specific attention to the nature, extent and time course of aggregation when considering its overall influence on tissue perfusion. A detailed understanding of aggregation effects is important from a clinical point of view since it may be enhanced during a variety of pathophysiological processes, including infections, circulatory and metabolic disorders, hematological pathologies and several other disease states. Altered RBC aggregation may be an indicator of disease as well as a factor affecting the course of the clinical condition; the prognostic value of RBC aggregation indices has been demonstrated in various diseases. Currently, RBC aggregation is an easily and accurately measurable parameter, and therefore may be expected to have broader clinical usage in the future.

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Erythrocyte aggregation: basic aspects and clinical importance

The erythrocyte sedimentation rate (ESR) remains the most widely used laboratory test for monitoring the course of infections, inflammatory diseases, and some types of cancer Several test methods have been developed recently, and as a result the safety and reliability of ESR testing procedures have improved The method recommended by the International Council for Standardization in Haematology and the National Committee for Clinical Laboratory Standards for ESR measurement is based on the traditional Westergren method, using EDTA-anticoagulated samples without dilution In clinical laboratories, reliable methods for calibration and the use of appropriate control materials are required for monitoring the accuracy and precision of the routine method We describe and evaluate a procedure for achieving the daily quality control of ESR and for establishing the limits of agreement between working and reference methods Data from routine patient samples were used to calculate the daily cumulative mean and to monitor its reproducibility over time Finally, to monitor analytic performance, a comparison was made between results from the measurement of ESR in specimens stored at 4°C for 24 hours and results obtained in fresh samples

Erythrocyte sedimentation rate: use of fresh blood for quality control.

Basic Examination of Blood and Bone Marrow

In recognition of the need for a standardization of the measurement of the erythrocyte sedimentation rate (ESR), the International Council for Standardization in Haematology makes the following recommendations: (i) The reference method for measurement of the ESR should be based on the Westergren method, which is a specific test for the ESR, with modifications, (ii) The reference method for measurement of the ESR should use either whole blood anticoagulated with EDTA and later diluted with sodium citrate or saline (4 : 1) or whole blood anticoagulated with sodium citrate (4 : 1) in Westergren pipettes, (iii) The ESR pipettes can be of glass or plastic (with specific characteristics). It must be colourless; a minimum sedimentation scale of 200 mm, a minimum bore of 2.55 mm, which should be constant within 5%. A protocol for the evaluation of alternative methodologies against the reference method is outlined: The new technologies must be tested over a range of ESR values of 2-120 mm. In this comparison, 95% of the differences should be 5 mm or less, with larger differences associated with higher ESR values. A minimum of 40 samples should be tested in 3 different groups of values: 1-20, 21-60 and more than 60 mm. The statistical methods recommended for ESR evaluations are the coefficient of correlation, the Passing-Bablock regression and the Bland-Altman statistical method. This reference method replaces all earlier standardized and reference methods.

/pdf/icsh-review-of-the-measurement-of-the-erythocyte-1ja007h4w1.pdf

ICSH review of the measurement of the erythocyte sedimentation rate

Background:Striking similarities between autoimmune gastritis and H. pylori-associated gastritis have suggested a potential link between these two pathological conditions in the progression of chronic atrophic gastritis (CAG), however, evidence has remained conflicting. Methods:Serum pepsinogen I and II, and antibodies against H. pylori in general, the cytotoxin-associated gene A protein (CagA) and parietal cells were measured by ELISA in 9684 subjects aged 50-74 years. Antigastric parietal cell antibody (APCA) prevalence was examined in the overall population and according to sex, age and H. pylori serostatus. The association between APCA prevalence and CAG was assessed by logistic regression, overall and according to H. pylori status, controlling for potential confounding factors. Results:Overall APCA prevalence was 19.5%. APCA prevalence was strongly associated with CAG, and the association was increasing with increasing severity of CAG. Furthermore, the association between APCA and CAG was even stronger among H. pylori negative subjects (odds ratio (OR) =11.3 (95% confidence interval (CI), 7.5-17.1)) than among H. pylori positive subjects (OR =2.6 (95% CI, 2.1-3.3)). Conclusions:APCA may play a role on the development of gastric atrophy, irrespective of H. pylori infection. Impact:Assessment of APCA might be a useful complement to established markers (such as pepsinogens and H. pylori antibodies) in screening for CAG.

https://cebp.aacrjournals.org/content/cebp/22/5/821.full.pdf

Gastric Parietal Cell Antibodies, Helicobacter Pylori Infection, and Chronic Atrophic Gastritis: Evidence from a Large Population-based Study in Germany

We evaluated performance of the TEST 1 (SIRE Analytical Systems, Udine, Italy), a fully automated analyzer for the measurement of the erythrocyte sedimentation rate (ESR). Intra-assay reproducibility was satisfactory for a wide range of ESR values, whereas there was a significant decrease in ESR data when the samples were stored at 4 degrees C for up to 24 hours. We compared TEST 1 with the Westergren ESR method approved by the International Council for Standardization in Haematology (ICSH) and with the Diesse Ves-Matic analyzer Linear regression analysis comparing the TEST 1 and the ICSH reference method yielded satisfactory correlations for K3 EDTA- and sodium citrate-anticoagulated samples. Bland-Altman analysis showed no evidence of a systematic bias between the TEST 1 and the reference method. A close correlation was found between the TEST 1 system and the Diesse Ves-Matic analyzer despite a significant positive systematic bias. Reference values for men and women were analyzed according to nonparametric statistics. The TEST 1 was easy to use, had a satisfactory operative practicability required minimal maintenance, and reduced contact with potential biohazards. This system enables the determination of ESR with any common standard-sized tube; the use of samples anticoagulated with K3 EDTA can widely reduce the workload in clinical laboratories.

The TEST 1 automated system: a new method for measuring the erythrocyte sedimentation rate.

The aim of the study was to ascertain whether there is an association between the presence of serum parietal cell autoantibodies (PCA) and: (1)Helicobacter pylori infection; (2) de presence and degree of gastritis and intestinal metaplasia; and (3) theH. pylori infecting strain. Gastric mucosal biopsies were obtained from 49 consecutive patients in order to assess and grade gastritis, make a histological diagnosis, and culture and genotypeH. pylori. H. pylori infection was present in 26 patients (group 1), had been present in 17 patients (group 2), and the remaining 6 (group 3) had never had the infection. The infecting strain wascagA positive in 21 of 26 group 1 patients. Positive PCA results were found in 84%, 76%, and 14% of patients in groups 1, 2, and 3, respectively. PCA results were correlated with anti-H. pylori antibody titers (P<0.05). In group 2 patients, PCA were associated with the degree of antral gastritis (Fisher’s exact testP<0.05).cagA status was not associated with the presence of PCA (X2=0.68, NS). The frequency of positive findings for PCA in group 2 was higher in patients with (90%) than in those without (50%) intestinal metaplasia. In conclusion: (1)H. pylori infection is associated with the production of PCA, which, after eradication of the infection, persist and might contribute to the persistent antral chronic gastritis and intestinal metaplasia; (2) the gastric lesions associated with infections sustained by the morevirulentH. pylori strains do not appear to be due to the induction of antigastric autoantibodies.

Antigastric autoantibodies in Helicobacter pylori infection: role in gastric mucosal inflammation.

In the present study we ascertained whether cagA positive and negative H. pylori strains release water soluble products that can influence the production of gastric mucosal cytokines and endocrine (gastrin) or exocrine (pepsinogen C) secretion in 23 H. pylori positive and 19 H. pylori negative patients. Antral biopsies were obtained to classify inflammation, activity, atrophy, intestinal metaplasia and H. pylori density grade. The cagA gene was identified by means of the polymerase chain reaction (PCR) in H. pylori positive colonies after culture of mucosal samples. Three antral biopsies from each patient were incubated with (1.) Water extracts from cagA positive, (2.) Water extracts from cagA negative strains or (3.) H2O (control) at 37 degrees C in a CO2 incubator for 24 hrs. Gastrin, pepsinogen C, IL-1 beta, IL-8, GMCSF, and TNF alpha were measured in the supernatants and mucosal homogenates. H. pylori infection was significantly associated with an increased antral inflammation and activity (chi 2 = 21.7, p < 0.001 and chi 2 = 42.0, p < 0.001), and increased mucosal levels of IL-1 beta, IL-8 and TNF alpha. Water extracts from cagA positive strains enhanced the release of PGC in mucosal biopsy supernatants (p < 0.05) when patients were considered overall and the release of TNF alpha (p < 0.05) when only patients with duodenal ulcer were considered. Water extracts from cagA negative strains stimulated gastrin secretion (p < 0.05). None of the remaining cytokines were influenced by H. pylori water extracts. In conclusion, pepsinogen C and TNF alpha can be induced by cagA positive water extracts and may contribute to damage the gastric and duodenal mucosa. Our findings indicate that in patients with H. pylori infection the increase of the mucosal levels of IL-1 beta and IL-8 does not depend on H. pylori water soluble products, but probably depends on the entire bacterium.

E. Stockreiter

Papers

The TEST 1 automated system: a new method for measuring the erythrocyte sedimentation rate.

Antigastric autoantibodies in Helicobacter pylori infection: role in gastric mucosal inflammation.

Different effects of H. pylori water extracts on cytokines, pepsinogen C and gastrin mucosal release in patients with or without duodenal ulcer.