Elevated Carbohydrate Antigen 19-9 (CA 19-9) in Patients with Echinococcus Infection

Abstract

The carbohydrate antigen 19-9 (CA 19-9), a determinant (sialylated lacto-N-fucopentaose 119) of a circulating oligosaccharide antigen, is a frequently used tumor marker. Echinococcus spp. infects humans throughout the world and may be able to synthesize closely related molecules which could interfere with the measurement and interpretation of CA 19-9 concentration. The main objective of the present study was to determine the range of CA 19-9 levels in the sera of patients infected by E. granulosus (cystic hydatide disease; CYSHD) or E. multilocularis (alveolar hydatide disease; ALVHD). Serum samples were collected from patients (aged 10-85 years) over a period of 5 years: from 19 patients with CYSHD and from 20 patients with ALVHD. Infection was confirmed by positive Echinococcus serology and clinical evidence provided by imaging and/or histopathological findings. CA 19-9 was detectable in 13 patients with CYSHD (13.5 +/- 8.5 kU/l) and 13 patients with ALVHD (30.0 +/- 21 kU/l; p < 0.05). Thus ALVHD patients exhibited a significantly higher plasma level of CA 19-9 than CYSHD patients. The serum level of CA 19-9 assessed with an increased cut-off value (> 22 kU/l) was elevated in nine (45%) of 20 ALVHD patients compared to two (11%) of 19 CYSHD patients (p < 0.05). Sera from patients with Echinococcus multilocularis infection contain substances which cross-react with CA 19-9. These substances originate either from the parasite or are synthesized by the host in response to the infection, and possibly bear the Lewis-a antigen or closely related structures which are recognized by anti-CA 19-9 antibodies. Our findings are relevant to the investigation of patients presenting with cystic lesions for which the differential diagnosis includes an infectious or neoplastic origin.

A Major Echinococcus multilocularis Antigen Is a Mucin-type Glycoprotein

“…22). A basic link among cancer and the tumor-like growth and behavior of the E. multilocularis metacestode was given by the identification and characterization of the 14-3-3 protein overexpressed at the metacestode stage of the parasite and by the frequent expression of elevated carbohydrate antigen CA 19Ϫ9 levels (sialylated lacto-N-fucopentaose 119) in many E. multilocularis infected patients (24,25). Nevertheless, the presence of an ␣-linkage in structure B cannot be excluded.…”

Extremely high values of CA 19-9 in liver hydatidosis and frank biliary rupture

“…The epitope recognized by anti CA 19-9 antibodies is the sialylated Lewis-a antigen. This antigen ends with a characteristic carbohydrate sequence, and very similar sialylated fucose-containing glycans have been found in hydatid membranes of E. granulosus (2). These substances may bear the Lewis-a antigen or closely related structures, which are recognized by anti CA 19-9 antibodies, producing an elevation of CA 19-9 (11).…”

“…Pfister et al (2) showed that 11% of the patients with liver hydatidosis caused by E. granulosus presented an abnormal value of CA 19-9. On the other hand, Yuksel et al (1) noticed in their series of 40 patients that 65% presented a value above cut-off.…”

“…• The theory of Pfister et al (2) is that the blood from the patients with an Echinococcus infection may contain substances originating from the parasites, which have been sialylated either by the host's or parasite's metabolism. The epitope recognized by anti CA 19-9 antibodies is the sialylated Lewis-a antigen.…”

“…It was detected originally using a monoclonal antibody in human colon cancer cells growing in cell culture (2,4,5). Only 2% of healthy subjects show abnormal levels of CA 19-9 (2).…”