The prompt identification of a significant acute-phase response might have significant diagnostic and therapeutic implications in daily practice.1–3 This is especially true for clinicians who work in small clinics and group practices devoid of advanced laboratory facilities. A simple bedside low-cost and rapid evaluation of the acute-phase response might therefore be of special interest.
It is known that various proteins are synthesized by the liver after acute infections.6 Several of these proteins, and especially fibrinogen, immunoglobulins, haptoglobin, ceruloplasmin, α1 antitrypsin, orosomucoid, and even CRP itself, might be involved in the induction and or maintenance of erythrocyte aggregation.17–21 Although it was shown that fibrinogen has a dominant role in this aggregation,22 it is clear that other proteins are involved as well.23 We have taken advantage of this biologic phenomenon and used the erythrocytes as sensors for the presence of multiple adhesive proteins in their plasmatic milieu. By using accurate physical measurements, the degree of aggregation can turn into a diagnostic tool.24
An advantage of our slide test is that the images can be easily transmitted by telephone or Internet25 to an inflammation data center, where appropriate controls can be immediately matched.26 In fact, we have recently established such a data center where the inflammatory baseline profile of more than 2500 healthy individuals is available. These are individuals who are recruited during their routine annual checkup examination.
It can be argued that similar information can be obtained using the Westergren sedimentation rate. However, ESR is an indirect way of looking at the degree of erythrocyte aggregation. The advantage of looking directly at this aggregation has been shown by us in several clinical models in the past.27–30 In addition, results are obtained within a couple of minutes.
At first glance, it looks as if complicated systems of microscopy and image analysis are needed for our measurements. However, it is clear that by using simple electro-optical principles, our method could turn into a bedside test, similar to what is presently performed with glucometers. Such an approach might be relevant in women with PID, a frequent clinical dilemma for the gynecologist.
The CDC guidelines state that “Many episodes of PID go unrecognized.” Although some cases are asymptomatic, others are undiagnosed because the patient or the healthcare provider fails to recognize the implications of mild or nonspecific symptoms or signs (e.g., abnormal bleeding, dyspareunia, and vaginal discharge). Because of the difficulty of diagnosis and the potential for damage to the reproductive health of women even by apparently mild or atypical PID, healthcare providers should maintain a low threshold for the diagnosis of PID.9 We used the CDC clinical criteria, which are sensitive but not very specific. Laparoscopy and/or endometrial biopsy are more specific indicators of acute PID. Interestingly, in our study group, we noticed several women with increased aggregation results, whereas some of the other equivalent inflammation laboratory tests for PID were normal. There were 3 cases with normal ESR, 2 cases with a normal leukocyte count, and 2 cases with normal hs-CRP. These patients were clinically diagnosed as having PID despite some normal laboratory values. The difficult diagnosis of these patients was made easier because all had significantly elevated aggregation results. Increase in aggregation could be of additive value in these cases in which the diagnosis is difficult.
We conclude that the degree of erythrocyte aggregation as determined by the erythrocyte percent is elevated in PID in a similar way that it has been shown for other clinical models. Its simplicity, rapidity, and low cost should be further evaluated in the context of this frequent disease.
1. Hotchkiss RS, Karl IE. The pathophysiology and treatment of sepsis. N Engl J Med 2003; 348:138–150.
2. Pepys MB, Hirschfield GM. C-reactive protein: A critical update. J Clin Invest 2003; 111:1805–1812.
3. Warren HS, Suffredini AF, Eichacker PQ, Munford RS. Risks and benefits of activated protein C treatment for severe sepsis. N Engl J Med 2002; 347:1027–1030.
4. Fusman G, Mardi T, Justo D, et al. Red blood cell adhesiveness/aggregation, C-reactive protein, fibrinogen and erythrocyte sedimentation rate in healthy adults and in those with atherosclerotic risk factors. Am J Cardiol 2002; 90:561–563.
5. Gamzu R, Rotstein R, Fusman R, Zeltser D, Berliner AS, Kupferminc MJ. Increased erythrocyte adhesiveness and aggregation in peripheral venous blood of women with pregnancy-induced hypertension. Obstet Gynecol 2001; 98:307–312.
6. Gabay C, Kushner I. Acute-phase proteins and other systemic responses to inflammation. N Engl J Med 1999; 11:448–454.
7. Rotstein R, Landau T, Twig A, et al. The erythrocyte adhesiveness/aggregation test (EAAT). A new biomarker to reveal the low grade subclinical smoldering inflammation individuals with atherosclerotic risk factors. Atherosclerosis 2002; 165:343–351.
8. Rogowski O, Zeltser D, Rotstein R, et al. Correlated expression of adhesive properties for both white and red blood cells during inflammation. Biorheology 2000; 37:361–370.
9. Sexually transmitted diseased treatment guidelines—2002. MMWR Recomm Rep 2002; 51:1–78.
10. International Committee for Standardization in Hematology. Recommendation of measurement of erythrocyte sedimentation rate of human blood. Immunochemistry 1965; 2:235–254.
11. Clauss A. Gerinnungsphysiologische Schnellmethode zur Bestimmung des Fibrinogens. Acta Haematol Basel 1957; 17:237–246.
12. Rifai N, Tracy RP, Ridker PM. Clinical efficacy of an automated high-sensitivity C-reactive protein assay. Clin Chem 1999; 45:2136–2141.
13. Rotstein R, Zeltser D, Shapira I, et al. An inflammation meter to reveal the presence and extent of inflammation in older patients. J Am Geriatr Soc 2000; 48:1739–1741.
14. Rotstein R, Zeltser D, Shapira I, et al. The usefulness of an inflammation meter to detect the presence of infection/inflammation in elderly patients. J Gerontol A Biol Sci Med Sci 2002; 57:M122–M127.
15. Rotstein R, Fusman R, Zeltser D, et al. The picture of inflammation: A new concept that combines the white blood cell count and erythrocyte sedimentation rate into a new hematologic diagnostic modality. Acta Haematol 2001; 106:106–114.
16. Sharshun Y, Brill S, Mardi T, et al. Inflammation at a glance: Erythrocyte adhesiveness/aggregation to reveal the presence of inflammation in individuals with atherothrombosis. Heart Dis 2003; 5:182–183.
17. Weng X, Cloutier G, Beaulieu R, Roederer GO. Influence of acute-phase proteins on erythrocyte aggregation. Am J Physiol 1996; 271:H2346–H2352.
18. Weng X, Roederer GO, Beaulieu R, Cloutier G. Contribution of acute-phase proteins and cardiovascular risk factors to erythrocyte aggregation in normolipidemic and hyperlipidemic individuals. Thromb Haemost 1998; 80:903–908.
19. Fusman R, Zeltser D, Rotstein R, et al. INFLAMET: An image analyzer to display erythrocyte adhesiveness/aggregation. Eur J Intern Med 2000; 11:271–276.
20. Ben Ami R, Barshtein G, Zeltser D, et al. Parameters of red blood cell aggregation as correlates of the inflammatory state. Am J Physiol Heart Circ Physiol 2001; 280:H1982–H1988.
21. Ben Ami R, Barshtein G, Mardi T, et al. A synergistic effect of albumin and fibrinogen on immunoglobulin-induced red blood cell aggregation. Am J Physiol Heart Circ Physiol 2003; 285:H2663–H2669.
22. Schechner V, Shapira I, Berliner S, et al. Significant dominance of fibrinogen over immunoglobulins, C-reactive protein, cholesterol and triglycerides in maintaining increased red blood cell adhesiveness/aggregation: A model in hypercholaesterolemic patients. Eur J Clin Invest 2003; 33:955–961.
23. Ben Assayag E, Bornstein NM, Shapira I, et al. Inflammation sensitive proteins and erythrocyte aggregation atherothrombosis. Int J Cardiol. In press.
24. Avitzour D, Shapira I, Rotstein R, et al. Image analysis of erythrocyte adhesiveness/aggregation. Lab Med 2003; 34:213–216.
25. Rotstein R, Berliner S, Fusman R, et al. The usefulness of telemedicine for the detection of infection/inflammation at the point of care. Telemed J e-Health 2001; 7:317–323.
26. Cohen S, Tolshinsky T, Rogowski O, et al. Real time, control adjusted evaluation of intensity of the inflammatory response. J Inform Techn Healthcare 2003; 1:195–207.
27. Zeltser D, Rotstein R, Rogowski O, et al. The erythrocyte adhesiveness/aggregation (EAAT) in the peripheral blood of patients with ischemic heart and brain disease with normal fibrinogen concentrations. Appl Rheol 2000; 10:231–237.
28. Zeltser D, Bornstein NM, Rotstein R, Shapira I, Berliner S. The erythrocyte adhesiveness/aggregation test in the peripheral blood of patients with ischemic brain events. Acta Neurol Scand 2001; 103:316–319.
29. Berliner S, Rotstein R, Fusman R, et al. Increased erythrocyte adhesiveness/aggregation in the peripheral venous blood of patients with ischemic heart disease and an eventful course. Acta Cardiol 2001; 56:121–126.
30. Mardi T, Aviv F, Rotstein R, et al. Detection of thrombolysis-related reduction in red blood cell adhesiveness/aggregation by using a simple slide test. Cardiology 2002; 97:226–229.