Immunoglobulin G (IgG) Subclass and IgE Responses in Human Paragonimiases Caused by Three Different Species

Abstract

In 40 cases of human paragonimiases caused by Paragonimus westermani (20 cases), P. miyazakii (10 cases), andP. skrjabini (10 cases), responses of serum immunoglobulin G (IgG), IgG subclasses, and IgE were analyzed by immunoblotting with crude antigens prepared from egg, 4-week-old juvenile, and adult forms of P. westermani. The 32- and 35-kDa proteins in the adult extracts showed specific reactions regardless of the causative species (39 of 40 cases; 98%). Sera of patients infected with P. westermani and P. miyazakii reacted strongly with the 28-, 46-, and 94-kDa proteins of egg extracts, while those from patients infected with P. skrjabini reacted faintly. No sera from patients with other trematodiases (0 of 15 cases), cestodiases (0 of 20 cases), or lung cancer (0 of 5 cases) or from healthy controls (0 of 10 individuals) showed positive reactions. Analysis by IgG subclass revealed that IgG4 (33 of 40 cases; 83%) and IgG1 (29 of 40 cases; 73%) antibodies in the patient sera recognized the 32- and 35-kDa proteins predominantly. IgG3 reaction was found in 50% (10 of 20 cases) and 30% (3 of 10 cases) of the sera of patients infected with P. westermani and P. miyazakii, respectively. In an IgE immunoblot, 83% (33 of 40 cases) of the sera from paragonimiasis patients reacted with the 32- and 35-kDa proteins while no sera from patients with heterologous diseases and healthy controls showed a positive reaction. Both 32- and 35-kDa proteins in adult extracts of P. westermani were highly reliable for serodiagnosis of human paragonimiases.

Persisting antibody reaction in paragonimiasis after praziquantel treatment is elicited mainly by egg antigens

“…Low levels of specific antibody against the metacercarial extract may be due to the rarity of antigenic materials as shown in Fig. 1, in which specific antibodies reacted with only a few protein components (Kong et al, , 1998 even in the same protein concentrations. The crude extract of 4-week old juveniles showed the highest antibody levels in both active and chronic paragonimiasis by ELISA.…”

“…The crude extracts of different developmental stages of P. westermani including newly excysted metacercariae, 4-and 7-week old juveniles, 16-week old adults, and eggs were prepared as described previously Kang et al, 1995;Kong et al, 1998). In brief, the metacercariae were collected from naturally infected crayfish, Cambaroides similis.…”

“…The antibody tests have been reported to be highly sensitive compared to egg detection, also being able to diagnose ectopic infections. In serological diagnosis of paragonimiasis, crude extracts of the adult worms have widely been used (Cho et al, 1981;Slemenda et al, 1989;Kong et al, 1998). A partially purified or a recombinant cysteine protease has recently appeared to have high reliability in diagnosing active paragonimiasis (Ikeda et al, 1996;Ikeda, 1998aIkeda, , 1998bYun et al, 2000).…”

Identification of immunodominant excretory–secretory cysteine proteases of adult Paragonimus westermani by proteome analysis

“…viously been registered in the GenBank genomic database. These included the following: heat shock protein 70 (HSP70; spot 2), haptoglobins (spots 6, 17 and 18), glutathione S-transferases (GSTs; spots [23][24][25] and four different groups of CPs (spots 10, 11, 13, 14, 21, 28-36 and 38). The primary fractions of the spots were associated with CPs, in which more than ten protein spots (spots 28-36 and 38), along with a series of horizontal spots, were identified…”

“…P. westermani excretory-secretory CPs have also been demonstrated to stimulate the Th2 immune system, thereby inducing specific IgG4 antibody responses. They are now considered to be fairly reliable serodiagnostic antigens [19,20,[24][25][26]. However, these CPs have yet to be globally observed and precisely identified at the protein level.…”