Antigen recognition by IgG4 antibodies in human trichinellosis

Abstract

Summary:The antibody isotype response to Trichinella spiralis excretory/secretory (ES) products of muscle larva was examined using sera from patients with confirmed trichinellosis. Using Western blots we identify components of the ES antigen that are recognized by IgM and IgG antibodies. A 45 kDa component was strongly recognized by different antibody classes and subclasses. We observed a 45 kDa-specific lgG4 response that was detected exclusively using sera of patients with trichinellosis and not of patients with echinococcosis, filariasis, cysticercosis, ascariasis, strongyloidiasis or toxocariasis. These results are relevant for the diagnosis of human trichinellosis.KEYWORDS : human trichinellosis, ES antigen, 45 kDa, lgG4.M onitoring programs for detection of trichinellosis in slaughterhouse animals have dramatically decreased the incidence of human trichinellosis. However, in many parts of the world, including Europe, it continues to occur. Recent outbreaks of trichinellosis have been reported from Germany, France, Spain and Italy (Ancelle et al, 1998;Rodriguez et al., 1999); (Pozio 1998).In our laboratory the immunodiagnosis of trichinellosis is performed by using an enzyme-linked immunosorbent assay (ELISA) in which the excretory/secretory (ES) products of Trichinella spiralis muscle larvae are used as antigen (van Knapen et al., 1982 MATERIALS AND METHODST he excretory/secretory (ES) antigen was prepared using viable muscle larva of T. spiralis as previously described by Gamble (1985). The 45 kDa antigenic component was purified from freshly obtained muscle larva using two-step affinity chromatography as described by Homan et al. (1992) SERUM SAMPLES Serum samples from trichinellosis patients recently received at our laboratory and from an outbreak of trichinellosis that took place in Slupsk, Poland in 1991 were used in this study. The patients here studied were all at an early stage of trichinellosis. All serum samples used tested positive for IgM and/or IgG by means of ELISA using T. spiralis ES antigen. Infection was confirmed for several patients from the outbreak in Poland and for the other patients used in this study by identification of Trichinella larva in muscle biopsy.The source for T. spiralis infection for the outbreak was undercooked pork. Sera from our laboratory from echinococcosis, filariasis, cysticercosis, ascariasis, strongyloidiasis or toxocariasis patients were also included. WESTERN BLOTTING PROCEDUREThe ES antigen or the 45 kDa protein was solubilized under reducing conditions and electrephorized on Parasite, 2001, 8, S168-S171 ANTIGENS S168.

Trichinella spiralis infection and transplacental passage in human pregnancy

“…In the present study, the presence and levels of IgG4 anti-ML-ESP changed over time in serum samples from women. In line with Pinelli's findings (Pinelli et al, 2001(Pinelli et al, , 2004(Pinelli et al, , 2007, we did not find any correlations between the presence of serum IgG4 and acute or chronic phase of the infection, adding that in pregnancy did not modify this phenomenon.…”

Glycan microarray profiling of parasite infection sera identifies the LDNF glycan as a potential antigen for serodiagnosis of trichinellosis

“…Seven of these sera were from the diagnostic laboratory at the RIVM, 12 were from an outbreak in Turkey (2004) that was confirmed to be caused by Trichinella britovi (Akkoc et al, 2009) and 10 were from an outbreak in Poland (1991) caused by T. spiralis (Pinelli et al, 2001). The sera were tested both in a total Ig Trichinella -ELISA using ES antigen and confirmed with a Trichinella -immunoblot as previously described (Pinelli et al, 2001). In addition, 90 serum samples from patients that were serologically positive to the following infections were used: ascariasis, leishmaniasis, toxocariasis, echinococcosis, cysticercosis, amoebiasis, toxoplasmosis, borreliosis, and syphilis.…”

“…Results from the ELISA were considered positive (+) when the ratio was higher or equal to 1, and it was considered negative (−) when it was less than 1. The procedures for the Trichinella ES-ELISA and the Trichinella ES-immunoblot have been described previously (Pinelli et al, 2001)…”

Immunoproteomic analysis of Trichinella spiralis and Trichinella britovi excretory-secretory muscle larvae proteins recognized by sera from humans infected with Trichinella

“…those with highest intensity, were located in the region of 43-70 kDa and around 120 kDa. Several studies have evaluated the sensitivity and specificity of immunoblotting, and many of these have examined the main immunodominant proteins with diagnostic value, using E-S or muscle larvae extract [19,[24][25][26][27][28][29][30][31]. Although most published papers use E-S antigens prepared according to the International Commission on Trichinellosis (ICT) protocol, the final product can vary; therefore, the level of recognition of the E-S protein fractions may differ between published studies.…”