Antigens recognized by the human immune response to severe leptospirosis in Barbados

Abstract

SUMMARYSerum samples obtained from patients hospitalized in Barbados with severe leptospirosis were tested by the microscopic agglutination test (MAT), enzyme immunoassay (EIA) and immunoblotting with leptospires that had been isolated from these patients. While serum samples taken a few days after onset of symptoms often showed no apparent correlation between MAT and EIA, later sequential serum samples produced similar profiles in both tests during the course of infection. Immunoblotting sonicate from Leptospira interrogans serovars arborea, copenhageni and bim with patients' sera, revealed reactions with a number of bands that corresponded with outer envelope components. These components included lipopolysaccharide (LPS), flagella and other outer membrane proteins, in addition to a low-molecular-weight (MW) carbohydrate cross-reactive with members of the Leptospiraceae. IgM antibodies elicited in the first to second week after infection reacted mainly with LPS and the low-MW cross-reactive carbohydrate. Comparative analysis of isolates of the same serovar by sodium dodecyl sulphate polyacrylamide gel electrophoresis and immunoblotting showed that while two serovar arborea isolates were identical, serovar bim isolates differed significantly from each other. This difference was also observed in comparative MAT testing.

Development of an Enzyme-Linked Immunosorbent Assay Using a Recombinant LigA Fragment Comprising Repeat Domains 4 to 7.5 as an Antigen for Diagnosis of Equine Leptospirosis

“…It has been reported that 7 days after the onset of clinical symptoms in human patients, 62% had anti-LigB IgG antibodies as detected by WB analysis (13). Similar results with IgG antibody responses to other leptospiral recombinant proteins have also been reported (12,(36)(37)(38). This suggests that these horses were previously infected with Leptospira and developed a memory response upon re-exposure to Leptospira.…”

Leptospira Immunoglobulin-Like Proteins as a Serodiagnostic Marker for Acute Leptospirosis

“…Among sera from patients presenting with less than 7 days of symptoms, 62% had anti-rLigB IgG antibodies as detected by the immunoblot assay. Similar findings have been observed with IgG antibody responses to other Leptospira proteins (10,11,20,22). This may relate in part to a memory response in individuals with a prior exposure to leptospirosis.…”

In LipL32, the Major Leptospiral Lipoprotein, the C Terminus Is the Primary Immunogenic Domain and Mediates Interaction with Collagen IV and Plasma Fibronectin

“…3). With respect to the IgG response, the LipL32 C terminus was recognized by antibodies present in the sera of five patients during the acute phase of the disease, and the intermediate subfrag- (4,5,9,10,19,21). Our data indicate that LipL32 can be used as a diagnostic antigen for the acute and convalescent phases of patients with leptospirosis.…”