Some influences on the ESR and the fibrinogen level in healthy subjects

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.

Sex-specific differences in patients with psoriatic arthritis:a nationwide study from the Chinese Registry of Psoriatic Arthritis (CREPAR IV)

OBJECTIVES

To elucidate the sex-specific differences in demographic features, clinical characteristics, and quality of life in Chinese patients with psoriatic arthritis (PsA).

METHODS

A total of 1,074 patients with PsA registered between December 2018 and June 2021 from the Chinese REgistry of Psoriatic ARthritis (CREPAR) cohort were selected. The baseline data on demographics, clinical characteristics, commonly used laboratory tests, comorbidities, and quality of life assessments were collected for this cross-sectional analysis.

RESULTS

A total of 1,074 patients were included in this study, 585 (54.47%) of them were male and 489 (45.53%) were female. The age at PsA onset in male patients was earlier than that in female patients (38.10 ± 12.79 vs 40.37 ± 13.41, p = 0.005). For clinical characteristics, male patients presented with higher rates of axial involvement (43.89% vs 37.74%, p = 0.044) and nail involvement (66.15% vs 58.08%, p = 0.006), while female patients presented with higher rates of peripheral arthritis (89.57% vs 83.93%, p = 0.007). For laboratory tests, men presented with a higher percentage of HLA-B27 positivity than women (24.65% vs 16.70%, p = 0.002) and had higher levels of CRP (median 9.70 vs 5.65, p < 0.001). Regarding disease assessment indices, male patients scored higher in PASI and BASFI (median 5.00 vs 3.00, p = 0.007 and 1.80 vs 1.40, p = 0.012, respectively). No sex difference was found in rates of achieving remission. Factors associated with disease remission were also analyzed in both sexes.

CONCLUSION

Demographic and clinical characteristics tend to vary between male and female patients with PsA. Male patients reported more functional limitations in daily life. Key Points • The demographic and clinical features vary greatly between male and female patients with PsA. • Male patients reported more functional burden in daily life as measured by BASFI.

Serum YKL-40 Levels in Patients with Asthma or COPD: A Pilot Study

Background and Objectives: Bronchial asthma (BA) and chronic obstructive pulmonary disease (COPD) are not only common obstructive respiratory conditions but also major causes of morbidity and mortality worldwide. There is, however, a surprising lack of blood-based biomarkers for separating between these pulmonary disorders. The aim of this study was to assess the practical relevance of using serum YKL-40, single or combined, for this purpose. Materials and Methods: Subjects included Romanian patients with BA (n = 24) or COPD (n = 27). YKL-40, fibrinogen, pre-treatment C-reactive protein (CRP), post-treatment CRP, erythrocyte sedimentation rate, interleukin 6 (IL-6), procalcitonin (PCT), absolute neutrophil count, neutrophil percentage, absolute lymphocyte count, lymphocyte percentage, absolute eosinophil count, and eosinophil percentage were measured and compared between these patients. Results: This is the first study investigating the clinical significance of serum YKL-40 in delineating between COPD and BA in Caucasian populations. Only fibrinogen and YKL-40 levels were different between COPD and BA, with the measured values being significantly elevated. These patients exhibited distinct inflammatory profiles. Using the upper quartiles of these variables for the pooled study population (YKL-40: 5100 pg/mL; fibrinogen: 552 mg/dL) as cut-off values, subjects were classified into high or low groups. High YKL-40 adults revealed significantly increased PCT levels. High fibrinogen subjects, by contrast, showed significantly elevated IL-6 concentrations and pre-treatment CRP levels. Low YKL-40 and fibrinogen patients showed the absence of COPD. Conclusions: Combined use of serum YKL-40 and fibrinogen may be useful for identifying the absence of COPD.

Sex- and gender-related differences in psoriatic arthritis

Psoriatic arthritis (PsA) is an inflammatory musculoskeletal disease with a chronic, progressive course. Various aspects of PsA, including its clinical features, disease course and response to treatment, are influenced by sociodemographic characteristics of the patient. This includes patient sex, the biological attributes associated with being male or female, and gender, a sociocultural construct that comprises attitudes, traits and behaviours associated with being a man or a woman. An understanding of sex- and gender-related differences in PsA, as well as their underlying mechanisms, is therefore important for individualized care. In this narrative review, the influence of sex and gender on PsA manifestation and course, patient function and quality of life, and their association with comorbidities are described. Sex- and gender-related disparities in response to advanced therapies and their potential underlying mechanisms are delineated. Differences in pathophysiological mechanisms between male and female patients including genetics, immune and hormonal mechanisms are discussed. Finally, fertility and pregnancy outcomes in PsA are outlined. By adopting sex and gender lenses, this review is aimed at highlighting key differences between male and female patients with PsA and uncovering mechanisms underlying these differences, ultimately promoting individualized care of men and women with PsA and informing future research in this area.

A comparison of erythrocyte sedimentation rates of bloods anticoagulated with trisodium citrate and EDTA among TB presumptive patients at the University of Gondar comprehensive specialized hospital, northwest Ethiopia

OBJECTIVE

The purpose of this study was comparing the erythrocyte sedimentation rate (ESR) results of trisodium citrate (TSC) and ethylene diamine tetra-acetic acid (EDTA) anticoagulants. A comparative cross-sectional study was conducted at the University of Gondar specialized referral hospital, northwest Ethiopia. A total of 70 TB presumptive participants were recruited. From each of the 70 participants of the study, 3 and 1.6 ml of blood was collected in EDTA tubes and 0.4 ml of trisodium Citrate anticoagulant containing test tubes, respectively.

RESULTS

The mean ± SD values of ESR were 57.9 ± 41.45 mm/h in EDTA and 50.99 ± 43.5 mm/h in TSC anticoagulated blood. The mean difference of ESR values between EDTA and TSC blood (6.91 ± 13.66 mm/h) was statistically significant. The Mean ± SD of ESR values using EDTA and TSC in males were 59.57 ± 42.31 and 53.57 ± 44.61 mm/h while for females it was 54.71 ± 40.44 and 46.04 ± 41.82 mm/h, respectively. The study indicated that there was a significant difference between ESR values with EDTA and TSC anticoagulants.

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.

Erythrocyte sedimentation rate as an independent prognostic marker for mortality: a prospective population-based cohort study

BACKGROUND

A very high erythrocyte sedimentation rate (ESR) is usually an indication of underlying pathology. Additionally, a moderately elevated ESR may also be attributable to biological ageing. Whether the ESR is a prognostic factor for mortality, regardless of age, has been scarcely investigated. Therefore, the objective was to analyse the association between elevated ESR levels and the risk of mortality in a prospective cohort of the general population.

METHODS

We studied data from the Rotterdam Study (1990-2014). ESR levels were measured at baseline and individuals were followed until death or end of study. Associations between moderately (20-50 mm h^-1 ) and markedly (>50 mm h^-1 ) elevated ESR levels and all-cause mortality were assessed using multivariate Cox proportional hazard models.

RESULTS

In total, 5226 participants were included, and the mean age was 70.3 years. During a median follow-up time of 14.9 years, 3749 participants died (71.7%). After adjustment, both a moderately elevated ESR and a markedly elevated ESR were associated with a significantly higher risk of overall mortality [hazard ratio (HR) 1.23, 95% confidence interval (CI) 1.12-1.35 and HR 1.89, 95% CI 1.38-2.60, respectively]. Although the ESR becomes higher with age, in a group aged above 75 years, without any comorbidities, an ESR > 20 mm h^-1 remained associated with a significantly increased risk of mortality (HR 1.29, 95%CI 1.01-1.64).

CONCLUSION

An elevated ESR is an independent prognostic factor for mortality. Despite the fact that ESR increases with age, it remains associated with an increased risk of mortality and warrants close follow-up.

Characterizing the Acute Phase Response in Healthy Patients Following Total Joint Arthroplasty: Predictable and Consistent

BACKGROUND

During surgery, trauma to musculoskeletal tissue induces a systemic reaction known as the acute phase response (APR). When excessive or prolonged, the APR has been implicated as an underlying cause of surgical complications. The purpose of this study was to determine the typical APR following total joint arthroplasty in a healthy population defined by the Charlson Comorbidity Index (CCI).

METHODS

This retrospective study identified 180 healthy patients (CCI < 2) who underwent total joint arthroplasty by a single surgeon for primary osteoarthritis from 2013 to 2015. Serial measurements of C-reactive protein (CRP) and fibrinogen were obtained preoperative, perioperative, and at 2 and 6 weeks postoperative.

RESULTS

Postoperative CRP peaked during the inpatient period and returned to baseline by 2 weeks. Fibrinogen peaked after CRP and returned to baseline by 6 weeks. Elevated preoperative CRP correlated with a more robust postoperative APR for both total hip arthroplasty and total knee arthroplasty, suggesting that a patient's preoperative inflammatory state correlates with the magnitude of the postoperative APR.

CONCLUSION

Measurement of preoperative acute phase reactants may provide an objective means to predict a patient's risk of postoperative dysregulation of the APR and complications.

Hypergammaglobulinemia in the pediatric population as a marker for underlying autoimmune disease: a retrospective cohort study

BACKGROUND

The significance of hypergammaglobulinemia as a marker of immune activation is unknown, as a differential diagnosis for hypergammaglobulinemia in children has not been adequately established. The goal of this study was to identify conditions associated with hypergammaglobulinemia in children, with the hypothesis that elevated immunoglobulin levels may precede or predict the development of autoimmune conditions.

METHODS

We reviewed the medical records for all children with IgG level ≥2000 mg/dL treated at a tertiary care children's hospital from January 1, 2000 through December 31, 2009. We compared clinical and laboratory features of these patients, and developed an algorithm to predict the likelihood of underlying autoimmunity based on these characteristics.

RESULTS

After excluding children who had received IVIG, a total of 442 patients with hypergammaglobulinemia were identified. Of these, nearly half had autoimmune conditions, most frequently systemic lupus erythematosus and lupus-related disorders. Autoimmune gastrointestinal disorders such as inflammatory bowel disease were also common. Infectious diseases were the next largest category of diseases, followed with much less frequency by malignant, drug-related, and other conditions. In comparison with non-autoimmune conditions, patients with autoimmune disease had higher IgG levels, lower white blood cell counts, lower hemoglobin values, and lower C-reactive protein (CRP) levels. Multivariable logistic regression confirmed that CRP (P = 0.002), white blood cell count (P < 0.001), hemoglobin (P = 0.015), and female gender (P < 0.001) are independent risk factors for autoimmune disease in patients with high IgG levels.

CONCLUSIONS

In a cohort of pediatric patients at a tertiary care children's hospital, hypergammaglobulinemia was most commonly associated with autoimmune diseases. In female patients with hypergammaglobulinemia, the presence of leukopenia, anemia, and normal CRP was 95% predictive of underlying autoimmune disease.

Inflammation as a predictor for delayed cerebral ischemia after aneurysmal subarachnoid haemorrhage

BACKGROUND

The mechanism of development of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (SAH) is poorly understood. Inflammatory processes are implicated in the development of ischemic stroke and may also predispose to the development of DCI following SAH. The objective of this study was to test whether concentrations of circulating inflammatory markers (C-reactive protein (CRP), interleukin-6 (IL-6) and interleukin 1 receptor antagonist (IL-1Ra)) were predictive for DCI following SAH. Secondary analyses considered white cell count (WCC) and erythrocyte sedimentation rate (ESR).

METHODS

This was a single-center case-control study nested within a prospective cohort. Plasma inflammatory markers were measured in patients up to 15 days after SAH (initial, peak, average, final and rate of change to final). Cases were defined as those developing DCI. Inflammatory markers were compared between cases and randomly selected matched controls.

RESULTS

Among the 179 participants there were 46 cases of DCI (26%). In primary analyses the rate of change of IL-6 was associated with DCI (OR 2.3 (95% CI 1.1 to 5.0); p=0.03). The final value and rate of change of WCC were associated with DCI (OR 1.2 (95% CI 1.0 to 1.3) and OR 1.3 (95% CI 1.0 to 1.6), respectively). High values of ESR were associated with DCI (OR 2.4 (95% CI 1.3 to 4.6) initial; OR 2.3 (95% CI 1.3 to 4.2) average; OR 2.1 (95% CI 1.1 to 3.9) peak; and OR 2.0 (95% CI 1.2 to 3.3) final value).

CONCLUSIONS

Leucocytosis and change in IL-6 prior to DCI reflect impending cerebral ischemia. The time-independent association of ESR with DCI after SAH may identify this as a risk factor. These data suggest that systemic inflammatory mechanisms may increase the susceptibility to the development of DCI after SAH.

Complement receptor 1 gene variants are associated with erythrocyte sedimentation rate

The erythrocyte sedimentation rate (ESR), a commonly performed test of the acute phase response, is the rate at which erythrocytes sediment in vitro in 1 hr. The molecular basis of erythrocyte sedimentation is unknown. To identify genetic variants associated with ESR, we carried out a genome-wide association study of 7607 patients in the Electronic Medical Records and Genomics (eMERGE) network. The discovery cohort consisted of 1979 individuals from the Mayo Clinic, and the replication cohort consisted of 5628 individuals from the remaining four eMERGE sites. A nonsynonymous SNP, rs6691117 (Val→IIe), in the complement receptor 1 gene (CR1) was associated with ESR (discovery cohort p = 7 × 10(-12), replication cohort p = 3 × 10(-14), combined cohort p = 9 × 10(-24)). We imputed 61 SNPs in CR1, and a "possibly damaging" SNP (rs2274567, His→Arg) in linkage disequilibrium (r(2) = 0.74) with rs6691117 was also associated with ESR (discovery p = 5 × 10(-11), replication p = 7 × 10(-17), and combined cohort p = 2 × 10(-25)). The two nonsynonymous SNPs in CR1 are near the C3b/C4b binding site, suggesting a possible mechanism by which the variants may influence ESR. In conclusion, genetic variation in CR1, which encodes a protein that clears complement-tagged inflammatory particles from the circulation, influences interindividual variation in ESR, highlighting an association between the innate immunity pathway and erythrocyte interactions.

ICSH review of the measurement of the erythocyte sedimentation rate

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.

Quality counts: new parameters in blood cell counting

Recently several parameters have been introduced to the complete blood count such as nucleated red blood cells, immature granulocytes; immature reticulocyte fraction, immature platelet fraction and red cell fragments as well as new parameters for detection of functional iron deficiency. Leucocyte positional parameters, which may diagnose specific diseases (e.g. differentiate between abnormal lymphocytes in leukaemia and viral conditions and may also detect malarial infection) are now available. At this time they are only used for research; however, generally such parameters later become reportable. One manufacturer's routine analyser allows measurement of cells by flow cytometry using monoclonal antibodies. Currently, there are no accredited external quality assessment schemes (EQAS) for these parameters. For a number of parameters, on some instruments, there is no internal quality control, which brings into question whether these parameters should be used for clinical decision making. Other more established parameters, such as mean platelet volume, red cell distribution width and the erythrocyte sedimentation rate do not have EQAS available. The UK National EQAS for General Haematology held a workshop earlier this year in 2008 to discuss these parameters. Participants were asked to provide a consensus opinion on which parameters are the most important for inclusion in future haematology EQAS.

ESR or CRP? A comparison of their clinical utility

OBJECTIVE

To review the normal reference values for erythrocyte sedimentation rate (ESR) and the significance of high values in the elderly, to re-examine the correlation, if any, between ESR and C-reactive protein (CRP) and to compare their utility and limitations for both health screening and clinical management of patients.

METHODS

CRP and ESR were measured in 295 blood samples from male and female subjects in whom their family doctors had found no clinically significant symptoms nor abnormal physical sign and in whom all other pathology tests gave normal results. None had been hospitalised during at least a six-week period prior to the study.

RESULTS

The results showed a mean ESR of 10 mm/1 h (range 0-25) in both males and females below the age of 40 yrs; this increased with age, to a mean of 18 mm (range 0-35) by 60 yrs in both men and women. In the CRP test, 95% of the samples in the >40 yrs group had CRP range of 0-18 mg/l compared with 0-10 mg/l in the younger subjects. The distribution plot of CRP results showed a left skew with mode at about 2 mg/l, whereas the equivalent ESR distribution shows a broad plateau with less skew. Thus, there was more overlapping of the numerical values for ESR and CRP in subjects younger than 40 yrs, as compared with those over 40 yrs old in whom the two sets of measurements were well separated. The relative utility of the two tests in clinical management of patients was also discussed. Different rates of increase and subsequent fall in the test results were shown over several weeks on a patient with an acute infection. Initially, both tests were increased, but after antibiotic therapy the CRP returned to normal indicating that remission had occurred, whereas the ESR remained high, indicating persistence of the infection. A subsequent dramatic increase in CRP to 180 mg/l confirmed the re-infection that had been indicated earlier by the ESR. After further antibiotic therapy CRP fell to normal, followed later by a slower reduction in ESR to a normal value for the patient's age.

CONCLUSION

This study confirms that after the age of 40, there is an age-related elevation of ESR, increasing steadily, especially after age 60 yrs. CRP is also affected by age, but to a much less extent. ESR and CRP appear to be equally useful and reliable as a screening test. Accordingly, in deciding which test should be carried out account must be taken of their relative convenience and cost. However, when required as a clinical test in the management of patients with specific diseases both tests should be carried out in tandem.

Comparison of the erythrocyte sedimentation rate measured by the Micro Test 1 sedimentation analyzer and the conventional Westergren method

BACKGROUND

The erythrocyte sedimentation rate (ESR) remains the most widely used laboratory test for monitoring 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 purpose of this study was the comparison of two methods, the traditional manual Westergren method (reference method of the International Committee on Standardization in Hematology) and a new semiautomated technique, the Micro Test 1 for determining the ESR.

SUBJECTS AND METHODS

Blood samples were collected after a night's fasting from 200 hospitalized and ambulatory patients. Undiluted blood samples anticoagulated with K3 EDTA that had Micro Test 1 values ranging from 2-82 mm/h were used for comparison with the Westergren method.

RESULTS

Linear regression analysis comparing the Micro Test 1 and the reference method yielded satisfactory correlations and regression for samples (r=0.910; P=0.0001; y=4.91+0.86 x; Sy/x=6.85). A Bland-Altman analysis showed no evidence of systematic bias between the Micro Test 1 and the reference method.

CONCLUSION

The Micro Test 1 system was easy to use, had a satisfactory operative practicability, required minimal maintenance, and reduced contact with potential biohazards.

Effects of cigarette smoking on diagnostic tests for work-related hypersensitivity pneumonitis: data from an outbreak of lung disease in metalworkers

BACKGROUND

It is widely believed that development of hypersensitivity pneumonitis (HP) is forestalled in cigarette smokers. We encountered the largest outbreak of HP in metalworkers yet reported [Hodgson et al. (2001): Am J Ind Med 39:616-628] and subsequently did a chart review of the 61 patients seen in connection with the outbreak [Dangman et al. (2002a): Am J Resp Crit Care Med 165(8):A528; Dangman et al. (2002b): Am J Ind Med 42:150-162], developing a diagnostic index for this disease.

METHODS

A re-examination of data from the chart review was carried out to explore possible effects of cigarette smoking on the clinical tests used to diagnose HP [Hodgson et al. (2001): Am J Ind Med 39:616-628].

RESULTS

Cigarette smokers with HP were less likely than non-smokers with HP to develop crackles in the lungs, elevated erythrocyte sedimentation rates (ESRs), and restrictive spirometry. Smoking habits had little effect on diffusion capacity and alveolar-arterial oxygen gradients in the patients with HP. Smokers were more likely to have abnormal gallium scans than non-smokers.

CONCLUSIONS

It appears that cigarette smoking can affect the physical examination findings, spirometry, and ESR changes associated with HP, making these tests less sensitive and specific, and potentially obscuring the diagnosis. Such changes may contribute to the apparent "protective" effect of smoking on the development of HP.

Haemoglobin concentration and erythrocyte sedimentation rate in primary care patients

The erythrocyte sedimentation rate (ESR) remains a commonly measured indicator of disease, but is subject to several non-disease influences. The haemoglobin concentration (Hb) and ESR were measured in 1249 consecutive patients (492 men, 757 women) from primary care practices. An inverse correlation was found between Hb and ESR throughout the range of measured Hb, and in particular there was a significant difference in the median ESR of patients in the highest and lowest quartile for non-anaemic Hb (P < 0.001). These results indicate that correct clinical analysis of an ESR result should take into account the Hb, both in anaemic and in non-anaemic patients. Interpretative difficulties due to external influences on the measured ESR could be resolved by replacement of this test with plasma viscosity estimation.

Clinical utility of erythrocyte sedimentation rate and plasma protein analysis in the elderly

The utilization and interpretation of the erythrocyte sedimentation rate in the elderly have been surrounded by controversy and confusion. To improve the understanding of the erythrocyte sedimentation rate and its determinants in the aged, a defined population of 111 ambulatory, retirement-home residents underwent thorough clinical and laboratory evaluation. Westergren erythrocyte sedimentation rate, Wintrobe erythrocyte sedimentation rate, and plasma viscosity measurements were all significantly correlated with one another as well as with plasma proteins, particularly fibrinogen and globulins. Age per se had no influence on the erythrocyte sedimentation rate in the study population. On the basis of standard upper limits of normal for younger populations, the Wintrobe sedimentation rate was most commonly abnormal and plasma viscosity least commonly abnormal. The "normal" upper limit of 20 mm/hour for Westergren sedimentation rate was also the optimal limit of normal by receiver operating characteristic analysis of the study population. Although the sensitivity of the Westergren sedimentation rate for the presence of an inflammatory condition or monoclonal gammopathy was only 0.55, the specificity was 0.96, and the positive predictive value of an elevated erythrocyte sedimentation rate being associated with a clinical disorder was 0.93. The enhanced clinical utility of the erythrocyte sedimentation rate in this population compared with other elderly populations may be due to a low prevalence of anemia and hypoalbuminemia. In such populations, the erythrocyte sedimentation rate may remain a useful clinical test, regardless of patient age.