Mechanism of ESR:
Why ESR increases,let see…
ESR means per unit time how much RBC settle down when the blood if a patient is kept in a tube.And it is expressed in how much millimetres in first hour
There are 2 renowned method of ESR measurement and those are
*Wintrobe’s Method
*Westergren method
Normally #RBC is #Negatively charged due to carboxy terminal in sialic acid of RBC membrane and we know that same charged particle will not attract each other.Any condition responsible for #reducing_surface charge of RBC will cause increased ESR cause decrease in charge will attract RBC each other and then rouleaux formation will occur which have more mass to surface ratio and will settle down easily.And ESR will be increased.
For example in inflammatory/infective condition there will be release of acute phase protein among them #fibrinogen is important which poses positive charge.It will reduce the negative charge of RBC and will cause more rouleaux formation and thus increased ESR.
In situation where immune globulin increases including multiple myeloma will cause very raised ESR.The explanation is immunoglobulin is positively charged and Wii cause decreased negative charge of RBC and will augment rouleaux formation and ultimately increased ESR.
When there is hypoalbuminemia that can also cause raised ESR cause albumin is negative charge.So it tries to keep RBC separately.But if it is lost due to any cause eg. Nephrotic Syndrome,the there will be more rouleaux formation and there will be raised ESR.
If rouleaux formation is hammered in some causes such as sickle cell disease then there will be decreased ESR.
Thanks for reading.
Refernce:
Marshall SE,Johnston SL.Clinical immunology. In: Ralston SH, Penman ID, Strachan WJ, Hobson RP.(eds). Davidson’s Principles and Practice of Medicine. 23rd ed. Edinburgh: Elsevier;2018.p.72