Hello, for my SIP I have already started on my Major project which is on the evaluation of a machine that analyses on PCT. I will describe the PCT in detail in this post.
The prohormone precursor for CT is a 116-amino acid polypeptide which has three component peptides, a 57-amino acid peptide at the amino-terminus, named aminoprocalcitonin (aminopro-CT), a centrally placed 33-amino acid immature CT and a 21-amino acid CT carboxyl-terminus peptide-I. its expression is induced several fold in the systemic bacterial infection and sepsis to elevated levels found in blood.
PCT has been demonstrated to be the best marker for differentiating patients with sepsis from those with systemic inflammatory reaction not related to infectious cause. Procalcitonin provides support for early diagnosis and allows critical decision making which could direct an effective treatment at the proper timing and also to save unnecessary costs in the use of appropriate antibiotics for critically ill patients. Produced in numerous neuroendocrine cells such as the thyroid glands and present in very low concentrations in blood, it has been shown that systemic bacterial infection causes a marked increase in PCT expression (encoded in the Calc-1 gene), hence its clinical utility as a indicator of sepsis of bacterial origin. Very significant concentrations of procalcitonin (up to 1000 ng/ml) can be detected in the patient sample with severe bacterial infection/sepsis
The prohormone precursor for CT is a 116-amino acid polypeptide which has three component peptides, a 57-amino acid peptide at the amino-terminus, named aminoprocalcitonin (aminopro-CT), a centrally placed 33-amino acid immature CT and a 21-amino acid CT carboxyl-terminus peptide-I. its expression is induced several fold in the systemic bacterial infection and sepsis to elevated levels found in blood.
PCT has been demonstrated to be the best marker for differentiating patients with sepsis from those with systemic inflammatory reaction not related to infectious cause. Procalcitonin provides support for early diagnosis and allows critical decision making which could direct an effective treatment at the proper timing and also to save unnecessary costs in the use of appropriate antibiotics for critically ill patients. Produced in numerous neuroendocrine cells such as the thyroid glands and present in very low concentrations in blood, it has been shown that systemic bacterial infection causes a marked increase in PCT expression (encoded in the Calc-1 gene), hence its clinical utility as a indicator of sepsis of bacterial origin. Very significant concentrations of procalcitonin (up to 1000 ng/ml) can be detected in the patient sample with severe bacterial infection/sepsis
The inflammatory and sepsis markers present now are IF-2, IF-6, IF-8, PCT, CRP and TNF-α. PCT has currently show in recent studies that it has better specificity and sensitivity over the classical sepsis markers in systemic sepsis, moreover, it has a higher and earlier increase during sepsis, and the level of PCT present usually correlates with the severity of the disease.
PCT compared to CRP
In this diagram PCT is shown to have a higher pooled sensitivity and specificity over C reactive protein, which is a classic inflammatory marker.
References: http://www.procalitonin.com/
http://www.jle.com/
In this diagram PCT is shown to have a higher pooled sensitivity and specificity over C reactive protein, which is a classic inflammatory marker.
References: http://www.procalitonin.com/
http://www.jle.com/
yuxuan
6 comments:
Hi thanx for the post
I would like to ask, what produces this protein in large amounts during syatemic bacterial infection?
Thanx Johan
0606637G
TG01
Hi Yu Xuan,
That was some really detailed description.
Anyway,was just wondering, might i ask how your MP relates to the "evaluation of a machine that analyses on PCT"?
Also, you mentioned of "classical sepsis markers" in the blog. Could you give some examples of these and perhaps also descibe how differently they might be produced as compared to PCT that would make them les suitable for detecting a bacterial infection/sepsis please?
Big thanks there!
Alexander Soo TG02
0608122H
hey,
do you conduct pct in your lab??
and whether you run a pct-rapid using a kit?? Coz at my plce, we run using the kit first, b4 we proceed to running in the machine...
sofie
Hi Yuxuan,
Very detailed post...! :)
Got some questions...Hope you don't mind!
1)What does CT stand for? (hope it is not a stupid question...:) )
2)What are the functions of the three component peptides of the prohormone precursor for CT?
3)What is the machine that you use for the analysis of PCT?
4)Who have sequence the Calc-1 gene and how is it sequenced?
Thankz!
Han Yang
TG01
to johan. PCT is not produced by the WBC unlike other inflammatory markers. its still widely researched but it seems to come from liver cell and such (unsure)
to alex: other kinds will be like CRP- C reactive protein, IL-6, IL-8
to sofie: it seems tat we do not run any kit. just start up the machine run controls and prepare for samples that we choose
to hanyang CT is calcitonin =)and by themselves the 3 parts of PCT do not have much use unless they become mature CT which affects bones. but they are a sign of sepsis when elevated. regarding the 3rd I'm not sure. i'll help u find if i have time
yuxuan( above post too)
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