DISCUSSION AND CONCLUSION
My sincere thanks goes to the academic department of Atlantic International University, Hawaii, USA especially my tutor Cyndy Dominguez, my academic advisors Linda Collazo and Dr. Edgar Colon. These talented teachers improved me a lot on research methods embedded with andragogic system and their efforts are highly appreciated.
Erythrocyte sedimentation rate (ESR) by Westergreen and Ziehl- Neelsen staining techniques were performed on 128 samples collected between January 2010 to November 2011 in the city of Porto Novo ,Cape Verde among whom 73(57%) were males and 55(43%) were females. 8(6.25%) were positive for tuberculosis with elevated ESR in all the eight samples. In all the samples, 77.3% showed elevated ESR without evidence of pulmonary tuberculosis and elevated ESR were influenced by age. In conclusion, ESR could serve as an important prognostic index but not a diagnostic index unless used in conjunction with other specific tests such as cultural techniques, nucleic acid probes and nucleic acid amplification using polymerase chain reaction (PCR). ESR left alone cannot serve as an important diagnostic index for tuberculosis since elevated results were recorded even in the absence of disease.
KEYWORDS: Erythrocyte Sedimentation rate, Diagnostic index, pulmonary, Tuberculosis
AIM: To evaluate the clinical utility of erythrocyte sedimentation rate(ESR) in the diagnosis of pulmonary tuberculosis.
LIMITATIONS OF THE TEST: Sputum samples were not bacteriological cultured because of high cost of reagents.
Corresponding Author: Peter Ubah Okeke
School of Science & Engineering
Atlantic International University
The erythrocyte sedimentation rate(ESR) is a non- specific test. Although an empirical test, the estimation of the erythrocyte sedimentation rate has been widely used in clinical medicine. The method for measuring the ESR recommended by the international council for standardization in hematology (ICSH 1993) and also by various national authorities (NCCLS 2000) is based on that of Westergreen, who developed the test in 1921 for studying patients with pulmonary tuberculosis.
Essentially, it is the measurement after 1hour of the sedimentation of red cells in diluted blood in an open ended glass tube of 30cm length mounted vertically on a stand Lewis S M (2006). The phenomenon of ESR has been exhaustively investigated and the rate of fall of the red cells is influenced by a number of inter-reacting factors Hardwicke J et al (1952). Basically, it depends upon the difference in specific gravity between red cells and plasma but the actual rate of fall is influenced very greatly by the extent to which the red cells form rouleaux, which sediment more rapidly than single cells. Other factors which affect sedimentation include the ratio of red cells to plasma, that is the packed cell volume(PCV), the plasma viscosity, the verticality or otherwise of the sedimentation tube, the bore of the tube and the dilution if any of the blood Thygesen J E (1942).
The all-important rouleaux formation is mainly controlled by the concentrations of fibrinogen and other acute- phase proteins; for example haptoglobin, ceruloplasmin, α1 acid-glycoprotein, α1-antitrypsin and C-reactive protein. Rouleaux formation is also enhanced by the immunoglobulin but is retarded by Albumin.
Poole and Summers (1952) reported that anemia by altering the ratio of the red cells to plasma encourages rouleaux formation and accelerates sedimentation. Hence, in anemia, cellular factors may affect sedimentation. Thus, in iron deficiency anemia a reduction in the intrinsic ability of the red cells to sediment may compensate for the accelerating effect of an increased proportion of plasma.
Bruce T K (1998) stated that ESR occurs in three stages, the initial stage is a period of few minutes in which rouleaux formation occurs. In the second stage, the primary sedimentation occurs at a constant rate lasting about 30 minutes and in the final stage, the sedimented cells fall at a slower rate, forming a packed column of cells that will sediment no further.
Mosley and Bull (1981) concluded that the Wintrobe method is more sensitive when the ESR is low, whereas, when the sedimentation rate is high, the Westergreen method is preferably an indication of the patient´s clinical state. Lefrere J J et al (1988) said that increased ESR in subjects who are HIV- seropositive seems to be an early predictive marker of progression towards acquired immune deficiency syndrome(AIDS).
Fincher and Page (1986) reported that the ESR is less helpful in countries where chronic disease are rife, their study showed very high ESRs with a specificity of 0.99 and a positive predictive value of 0.9 for an acute or chronic infection. Bain B J (1983) expressed that ESR is higher in women than men and correlates with sex differences in fibrinogen levels. An increase in fibrinogen occurs in normal pregnancy, resulting in increased red cell aggregation and elevated sedimentation Van den Broek and Letsky (2001).
The experience of AL-Marri and Kirkpatrick (2000) reported that although an elevated ESR may be expected in children with tuberculosis, one-third of the children tested with tuberculosis had normal ESR and thus concluded that there is a little or no value in using ESR as a diagnostic index for tuberculosis.
Sanong Sansumran(2011) reported that erythrocyte sedimentation rate in pulmonary tuberculosis is extremely high regardless of the sputum smear microscopy result and its grading and thus concluded that ESR could be helpful in differential diagnosis of an adult patient who is highly suspected of having pulmonary tuberculosis and had sputum smear negative especially in an area where a sputum culture is not available.
- Quote paper
- Peter Ubah Okeke (Author), 2011, Erythrocyte Sedimentation Rate: Is It An Important Diagnostic Index For Pulmonary Tuberculosis?, Munich, GRIN Verlag, https://www.grin.com/document/183069