Specific cross-reactivity in sera from cystic echinococcosis patients in an enzyme-linked immunoelectrotransfer blot for cysticercosis diagnostics

Clinical Implications for the Comprehensive Interpretation of Radiologic and Immunodiagnostic Tests in Patients Suspected of Parasitic Hepatic Cyst, a Rare Case in Korea

Cystic echinococcosis (CE) is a representative neglected tropical disease (NTD) with increased morbidity and mortality but is ignored and overlooked in developed countries. Serological and radiographic findings are helpful in distinguishing these parasites; however, conflicting results of these can make it difficult to diagnose if medical knowledge of hepatic parasitic disease, including the etiology, features of imaging, and immunodiagnostic test, is not acquired. We report the case of a male patient with dyspepsia and right epigastric pain who had positive results for cysticercosis antibodies on immunodiagnostic examination. Abdominal ultrasonography revealed two huge communicating cystic lesions measuring 8–11 cm. Further evaluations for cysticercosis of the brain (neurocysticercosis) and eyes (intraocular cysticercosis) were unremarkable throughout the brain imaging test and fundus examination. A laparoscopic right hemi-hepatectomy was performed for diagnosis and treatment. On histopathological examination, diverse stages of Echinococcus granulosus were identified. Albendazole was administered postoperatively, and the patient was also followed up. We should be aware of the etiologies that have been prevalent in parasite infection thought to be the cause of hepatic cysts. Moreover, we make an effort to ascertain the patient’s nationality, past travel experiences, and immediate environment, including any animals and pets. We present the case of a patient who was worried about the possibility of liver invasion of cysticercus due to the positivity of the cysticercosis antibody and was ultimately diagnosed with CE.

Low sensitivity and frequent cross-reactions in commercially available antibody detection ELISA assays for Taenia solium cysticercosis

OBJECTIVE

To evaluate the diagnostic performance of two commercially available ELISA kits, Novalisa^® and Ridascreen^® , for the detection of antibodies to Taenia solium, compared to serological diagnosis of neurocysticercosis (NCC) by LLGP-EITB (electro-immunotransfer blot assay using lentil-lectin purified glycoprotein antigens).

METHODS

Archive serum samples from patients with viable NCC (n = 45) or resolved, calcified NCC (n = 45), as well as sera from patients with other cestode parasites (hymenolepiasis, n = 45 and cystic hydatid disease, n = 45), were evaluated for cysticercosis antibody detection using two ELISA kits, Novalisa^® and Ridascreen^® . All NCC samples had previously tested positive, and all samples from heterologous infections were negative on LLGP-EITB for cysticercosis. Positive rates were calculated by kit and sample group and compared between the two kits.

RESULTS

Compared to LLGP-EITB, the sensitivity of both ELISA assays to detect specific antibodies in patients with viable NCC was low (44.4% and 22.2%), and for calcified NCC, it was only 6.7% and 4.5%. Sera from patients with cystic hydatid disease were highly cross-reactive in both ELISA assays (38/45, 84.4%; and 25/45, 55.6%). Sera from patients with hymenolepiasis cross-reacted in five cases in one of the assays (11.1%) and in only one sample with the second assay (2.2%).

CONCLUSIONS

The performance of Novalisa^® and Ridascreen^® was poor. Antibody ELISA detection cannot be recommended for the diagnosis of neurocysticercosis.

Control of cysticercosis in Madagascar: beware of the pitfalls

Taenia solium cysticercosis is a zoonosis of public health importance in areas where the disease is endemic, with significant economic impacts on human health and the swine industry. Several gaps remain in the epidemiology of the parasite and the strategies of control in developing countries. We detail the key factors to consider in Madagascar in terms of the porcine husbandry system, Taenia transmission cycle, and diagnosis of cysticercosis in pigs, in order to better estimate the sanitary and economic impacts of this parasitic disease as well as to define an integrated control program.

Banding pattern indicative of echinococcosis in a commercial cysticercosis Western blot

Objective

A commercial cysticercosis Western blot was evaluated for serological cross-reactivity of sera from patients with alveolar (AE) and cystic echinococcosis (CE).

Methods

A total of 161 sera were examined, including 31 sera from AE-patients, 11 sera from CE-patients, 9 sera from patients with other parasitic diseases and 109 sera from patients with unrelated medical conditions. All AE-and CE-sera were also examined by the echinococcosis Western blot.

Results

More sera from patients with AE than with CE showed cross-reactivity in the form of ladder-like patterns ("Mikado aspect") and untypical bands at 6-8 kDa (71% and 77.4% versus 27.3% and 45.5%, respectively). In contrast, triplets of bands in the area above 50 kDa and between 24 and 39-42 kDa were more frequent in CE than in AE sera. The fuzzy band at 50-55 kDa typical for cysticercosis was absent in all AE and CE sera.

Conclusions

Atypical banding patterns in the cysticercosis Western blot should raise the suspicion of a metacestode infection different from Taenia solium, i.e. Echinococcus multilocularis or E. granulosus, especially when the Mikado aspect and an altered 6-8 kDa band is visible in the absence of a fuzzy 50-55 kDa band.