Immunosuppressive acidic protein in patients with brain tumours: a preliminary report.

The present investigation was conducted to document the serum concentrations of immunosuppressive acidic protein (IAP) in patients with intracranial tumours utilizing the single radial immunodiffusion method. Among 46 pre-operative patients, elevated serum levels of IAP were found in nine of 16 patients with gliomas, six of nine patients with metastasis, and two of 21 patients with non-glial, histologically benign intracranial tumours. The mean value of serum IAP in glial or metastatic tumours was found significantly higher than that of either non-glial or normal individuals. It was postulated that serum IAP levels could correlate with a grade of anaplasia and malignancy of the tumour. And it was also of note that serum IAP levels appeared to have a tendency to decrease in response to the treatment. In addition, serum IAP levels were found correlated with the clinical condition and course of disease as evaluated by performance status and erythrocyte sedimentation rate. Therefore, it was suggested that measurement of serum IAP could be, at least in part, useful in validating the histologic analysis of brain tumours, in following responses to treatment when used as a tumour indicator, and in monitoring the progress of the disease in patients in terms of performance status.