Value of blood tests including serum group IIA phospholipase A₂ and bactericidal/permeability‐increasing protein in Crohn's disease

Abstract

Objective. Determination of the activity of Crohn's disease at a defined time‐point is a challenging task since only endoscopy guidelines are given and secondary clinical findings, subjective symptoms and non‐specific laboratory tests have therefore to be relied on. The purpose of the current study was to investigate the ability of blood tests to differentiate patient groups with different clinical disease activity and different clinical outcomes during follow‐up in Crohn's disease. Material and methods. During a visit to hospital, 73 outpatients with Crohn's disease were examined, a clinical score was calculated and blood samples were collected for 22 laboratory tests. The patients were also grouped according to clinical outcome during a 6‐year follow‐up. Results. Serum group IIA phospholipase A₂ and α‐1‐antitrypsin values were outside the reference interval more frequently (62% and 42%, respectively) than the other tests in active Crohn's disease. Only weak correlations were found between the clinical score and the test values, and the best correlation was found with serum lysozyme (r = 0.40). In a logistic regression model, the best prediction of disease activity at entry to the study was reached with a model including serum orosomucoid and serum lysozyme and the best prediction of clinical outcome during follow‐up was reached using a model including serum albumin. Conclusions. Serum group IIA phospholipase A₂ appeared to be the most sensitive marker of inflammation in Crohn's disease among the 22 blood tests compared. No reliable predictions of disease activity at the time of blood sampling or clinical outcome later during follow‐up could be made from the blood tests studied.

• Biological marker
• enteritis
• clinical markers
• laboratory markers
• outcome
• regional ileitis
• terminal disease activity

Acknowledgements

We thank Dr. Kristiina Söderlund and Dr. Frank Laxén for examining some of the patients and for innovative discussions that improved this paper. We also thank the Finnish Red Cross Blood Transfusion Service and Dr. Allan Rajamäki and the staff of the Department of Haematology of the Central Laboratory of Turku University Central Hospital for co‐operation in collecting control serum samples. Ingeborg Waernbaum, PhD, Department of Statistics, Umeå University, is acknowledged for the statistical work in this study. The study was supported by the County Council of Västerbotten, Sweden, the Finnish Medical Society, the Research Fund of Turku University Central Hospital, The Finnish Medical Foundation and the Paulo Foundation.