Establishment of an ELISA for the Recognition of Procalcitonin Variants in Patients With Hyperprocalcitonemia.

Study Overview
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Brief Summary
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Procalcitonin is a protein consisting of 116 amino-acids which can rapidly rise under inflammatory conditions and sepsis. More than 20 years ago it has been shown that dipeptidylpeptidase-4 (DPP-4) cleaves procalcitonin from the n-terminus, resulting in a truncated procalcitonin-variant which consists of 114 aminoacids. Within our workgroup we found that the truncated procalcitonin-variant had deleterious effects on vascular integrity during sepsis in mice. However, it is unknown if this applies also in humans. By using an ELISA-assay we want to examine the ratio between native and truncated human procalcitonin during diseases accompanied with hyperprocalcitoninemia and correlate the results with clinical data.

Detailed Description
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Procalcitonin is a protein consisting of 116 amino-acids which can rapidly rise under inflammatory conditions and sepsis. More than 20 years ago it has been shown that dipeptidylpeptidase-4 (DPP-4) cleaves procalcitonin from the n-terminus, resulting in a truncated procalcitonin-variant which consists of 114 aminoacids. Within our workgroup we found that the truncated procalcitonin-variant had deleterious effects on vascular integrity during sepsis in mice: We observed that binding of truncated procalcitonin to the CRLR/RAMP1-receptor on vascular endothelium lead to phosphorylation and destruction of VE-cadherin, an essential part of adherens junctions. Consequently, paracellular leakage of proteins and fluid from blood vessels developed. It is unknown if these effects also apply to humans. By using an ELISA-assay we want to examine the ratio between native and truncated human procalcitonin during diseases accompanied with hyperprocalcitoninemia and correlate the results with clinical data. Futhermore, we want to examine if the procalcitonin-variants have influence on cytokine levels and surface antigens on immune cells by performing multiplex immunoassays and FACS-analysis.

Official Title
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Establishment of an Enzyme-linked Immunosorbent Assay for the Recognition of Procalcitonin Variants and Characterization of Procalcitonin Variants in Patients With Hyperprocalcitonemia.

Conditions
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Adiposity, Sepsis, Pre-Eclampsia, Granulomatosis With Polyangiitis, Microscopic Polyangiitis, SIRS, Procalcitonin

Intervention / Treatment
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* Diagnostic Test: Procalcitonin-variants ELISA-Assay


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age >18 Patients with diagnosis... Sepsis or, SIRS after cardiothoracic surgery or, adipositas or, granulomatosis with polyangiitis/microscopic polyangiitis or, pre-eclampsia healthy control subjects written informed consent Exclusion Criteria: participation in an interventional study trial within the last 3 months relationship to study investigator

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sepsis<br>Withdrawal of 3 blood collection tubes for ELISA-measurements at a single time during hyperprocalcitoninemia. | Diagnostic Test: Procalcitonin-variants ELISA-Assay<br>* Observational study measuring procalcitonin-variants in different patient collectives by obtaining 3 blood collection tubes per patient.<br>|
| SIRS<br>Withdrawal of 3 blood collection tubes for ELISA-measurements at a single time during hyperprocalcitoninemia. | Diagnostic Test: Procalcitonin-variants ELISA-Assay<br>* Observational study measuring procalcitonin-variants in different patient collectives by obtaining 3 blood collection tubes per patient.<br>|
| Adiposity<br>Withdrawal of 3 blood collection tubes for ELISA-measurements at a single time during hyperprocalcitoninemia. | Diagnostic Test: Procalcitonin-variants ELISA-Assay<br>* Observational study measuring procalcitonin-variants in different patient collectives by obtaining 3 blood collection tubes per patient.<br>|
| Granulomatosis with polyangiitis / microscopic polyangiitis<br>Withdrawal of 3 blood collection tubes for ELISA-measurements at a single time during hyperprocalcitoninemia. | Diagnostic Test: Procalcitonin-variants ELISA-Assay<br>* Observational study measuring procalcitonin-variants in different patient collectives by obtaining 3 blood collection tubes per patient.<br>|
| Pre-eclampsia<br>Withdrawal of 3 blood collection tubes for ELISA-measurements at a single time during hyperprocalcitoninemia. | Diagnostic Test: Procalcitonin-variants ELISA-Assay<br>* Observational study measuring procalcitonin-variants in different patient collectives by obtaining 3 blood collection tubes per patient.<br>|
| Healthy controls<br>Withdrawal of 3 blood collection tubes for ELISA-measurements at a single time during hyperprocalcitoninemia. | Diagnostic Test: Procalcitonin-variants ELISA-Assay<br>* Observational study measuring procalcitonin-variants in different patient collectives by obtaining 3 blood collection tubes per patient.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ratio between native and truncated procalcitonin during different conditions of hyperprocalcitoninemia | Measurement performed by using ELISA-assay. | Blood withdrawal takes approximately 5 minutes per patient | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| DPP-4-activity | Measurement performed by using a commercial DPP4-ELISA-kit. | Blood withdrawal takes approximately 5 minutes per patient | 
| Proinflammatory cytokines | Measurement performed by using a commercial multiplex immunoassay kit. | Blood withdrawal takes approximately 5 minutes per patient | 
| Immun cell surface-antigens | Measurement performed by using fluorescence-acivated cell sorting (FACS). | Blood withdrawal takes approximately 5 minutes per patient |