Haematology-ESR ( Sasi's)

Hi! Sasi here! Its my turn to blog! So, here I go....

Recently I have been attached to the Haematology department.

In this blog, I would like to highligh one test I frequently was assigned to do besides ABO blood grouping and FBC (which has been previously elaborated by Lizzie). The test would be ESR.

ESR stands for Erythrocyte Sedimentation rate. The rate at which the red blood cells falls is measured and reported in mm/h. It is an easy, cheap, non specific test that has been used for years to help diagnose conditions associated with acute and chronice inflammation including infections, cancers and auto immune diseases. According to a senior at work, I learnt that ESR is said to be non specific because increases in the rate do not tell exactly where the inflammation is in the body or what is causing it. For this reason, ESR is typically used in conjunction with other tests like Full Blood Count, Anitinuclear antibody etc to aid in the diagnosing aspect. ESR is particularly useful in diagnosing two specific inflammatory diseases, Temporal arteritis and Polymyalia Rheumatica. A high ESR is one of the main test results use to support the diagnosis. ESR is also used to monitor disease activivity and response to therapy in both of these diseases.

In our haematology lab, once the EDTA bloody tubes arrive,they are run in the FBC analyzers first. After FBC is run, ESR is run. ESR is given the very next priority as it has to be ensured that the blood volume is sufficient for the test. (Hence, that is why ABO is done last). After preparing the worklist for the ESR test, I had to alliguot the blood into the small tubes provided by the ESR commercial kit, mix it well with the anticoagulant in the tubes and make sure the sample is homogenous. Long pipettes are provided in the kit. These pipettes are thrusted into the tubes and I have to make sure the blood level reaches the brim of the pipette. Once the tubes are fit into the automated readers, it would take approximately 40 mins for the readings to be out.

When an inflammatory process is present, the high proportion of fibronogen in the blood causes red blood cells to stick to each other. The red cells form stacks called 'rouleaux' which settle faster. The height of the remaining plasma is read.

Samples with results more than 50 have to be rerun.The reference range applies as follows:

(ESR 95% limits) (Adults)
Age (years) 20 55 90
Men 12 14 19
Women 18 21 23

Children
Newborn: 0 to 2 mm/hr.
Neonatal to puberty: 3 to 13 mm/hr.
Newborn: 0-5 mm/hr.
Neonatal to puberty: 0-15 mm/hr.

A very high ESR may occur due to a marked increase in globulins, that can be due to a severe infection. The doctor would then order for other follow-up tests like cultures depending on the patient's symptoms.

A low ESR is seen with polycythemia which is the condition where a patient makes too many red blood cells or with extreme leokocytosis where the patient has too many white blood cells or with protein abnormalities. Some changes in red cell shape such as sickle cells in sickle cell anemia aso lowers the ESR.

That marks the end of my blog. Feel free to drop ya questions if any :) Take care!


Sasi
Tgo2
0503804g