Altered immunoglobulin A (IGA-1) levels in patients with advanced colorectal adenocarcinoma presenting with normal preoperative levels of carcinoembryonic antigen (CEA)

Abstract

We investigated the value of serum IgA-1 as a complementary tumour marker to carcinoembryonic antigen (CEA) in the monitoring of the postoperative follow-up of 19 patients with advanced colorectal carcinoma presenting with normal levels of CEA. Mean follow-up period was 14 months (range 2–72 months). Mean number of serum specimens was 5 (range 2–9). IgA-1 assay employed rabbit antihuman IgA for binding IgA-1 from patient's serum and peanut agglutinin to detect the IgA-1 O-glycosidic structure. Ten patients developed distant metastases while nine patients had locoregional recurrence. All 19 patients had generally persistent elevation of serum IgA-1 throughout the follow-up period while serum CEA levels were subsequently elevated in only 10 patients. IgA-1 predicted recurrence with an average lead time of 8 months (range 1–19 months). On the other hand, mean lag time for CEA was 12 months (range 6–50 months). The data indicate the clinical utility of serum IgA-1 as a potential complementary tumour marker to CEA in the monitoring of the postoperative course of this particular subset of colorectal cancer patients.