Laboratory evaluation of commercial immunoblot assay kit for serodiagnosis of Echinococcus infections using sera from patients with alveolar hydatidosis in Hokkaido

Using serum specimens from patients with alveolar hydatidosis (AH) in Hokkaido, we assessed the usefulness of "Echinococcus Western Blot IgG" (the French immunoblot assay, FIA), which has recently been launched from Ldbio Diagnostics (Lyon, France) as new commercial immunoblot assay kit of immunodiagnosis of Echinococcus infections. Eighty serum specimens were used for the present study: 64 preoperative sera and nine postoperative sera, which were taken from AH patients in Hokkaido, and seven sera from persons who were ELISA (enzyme-linked immunosorbent assay)--positive in mass screening which was conducted for checking on Echinococcus infections in Hokkaido since 1982. When the 64 preoperative sera were examined by the Western blotting method (the Hokkaido method of Western blotting, HWB) which had been carried out at Hokkaido Institute of Public Health between 1987 and 1993, it was found that 53 cases were positive and six cases were quasi-positive, i.e. the rate of the positive cases including quasi-positive cases was 92.2%. From immunostaining patterns, HWB-positive sera could be grouped in two types: the complete type, which showed a pattern of multiple bands containing the 55 and 66 kDa bands, and the incomplete type, which showed patterns of only few bands containing the AH-specific polysaccharide antigen named C antigen. Forty-three of the 53 HWB-positive sera were of the complete type and the residue was of the incomplete type. On the other hand, when the 64 preoperative sera were examined by FIA, 60 sera (93.8%) were judged to be positive and the others as negative sera. On the basis of the interpretation of immunostaining patterns described in the instruction manual, 47 (78.3%) of the 60 positive sera were regarded as pattern P3, five (8.3%) as pattern P4, and eight (13.3%) as pattern P5. All of the complete-type sera were regarded as P3, indicating high antibody titers. Contrarily, most of the incomplete-type or quasi-positive sera resulted in other patterns such as P4 and P5, indicating low antibody titers. Of 5 HWB-negative sera, two were FIA-positive (which showed P3 and P5 patterns respectively), however their immunoreactions were significantly low. Therefore, apart from interpretation of pathological conditions of cases with exceedingly low antibody titers, FIA may be able to give a serologically clear interpretation to HWB-quasi-positive cases, indicating that it is a highly sensitive and useful method for immunodiagnosis of Echinococcus infections.     

Polymerase chain reaction (PCR)-based molecular discrimination between Paragonimus westermani and P. miyazakii at the metacercarial stage

The metacercariae of the lung flukes, Paragonimus westermani and P. miyazakii, are of known medical importance as the pathogens causing human paragonimiasis. They are both found in the same freshwater crab species in Japan and are morphologically quite similar. The aim of the present study was to establish molecular methods for accurate discrimination between individual metacercariae of the two species. In the first step, we amplified and sequenced the second internal transcribed spacer (ITS2) region of ribosomal DNA. Searches of nucleotide databases revealed that the ITS2 sequences generated from the metacercarial DNA were identical to those previously reported for the adults of the respective species. Utilizing a nucleotide difference between the two species, we have established two PCR-based techniques; PCR-restriction fragment length polymorphism and direct PCR-amplification using species-specific primers. Both techniques showed that the individual metacercariae of the two species could be unequivocally discriminated from one another. The present results suggest that the ITS2 region is useful for species discrimination irrespective of the life cycle stages of the lung flukes. Established techniques can thus be used for epidemiological investigations of the prevalence of human lung fluke metacercariae.     

Trends of hepatitis B virus genotype distribution in chronic hepatitis B patients in Japan

Journal of Gastroenterology - Hepatitis B virus (HBV) is one of the most prevalent chronic viral infections that causes chronic hepatitis B (CHB). In Japan, genotypes B and C account for most of...     

SUV<Subscript>max</Subscript> on FDG-PET is a predictor of prognosis in patients with maxillary sinus cancer

Purpose

Our aim was to determine whether the maximum standardized uptake value (SUV_max) of the primary lesion demonstrated by [¹⁸F]-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is associated with the prognosis of maxillary sinus cancer.

Materials and methods

The relationships of clinicopathological factors including age, T stage, N stage, histologic type, treatment strategy, and primary tumor SUV_max with progression-free (PFS) and overall (OS) survival were evaluated using the log-rank test and Cox method in 31 patients with maxillary sinus cancer before combined superselective intra-arterial chemotherapy using high-dose cisplatin with concurrent radiotherapy, or radiotherapy alone.

Results

The median duration of follow-up was 55.4 (range 9.7–72.6) months. PFS and OS of patients exhibiting a high SUV_max (≥16 and ≥17, respectively) for the primary tumor were significantly lower than those of patients for whom the primary tumor SUV_max was low (p = 0.0010 and p = 0.033, respectively). Multivariate analyses showed that T stage (p = 0.0049) and primary tumor SUV_max (p = 0.026) were independently prognostic of poorer PFS and that only primary tumor SUV_max (p = 0.049) was independently prognostic of poorer OS.

Conclusion

SUV_max of the primary tumor determined by FDG-PET/CT before treatment could be a good surrogate marker for prognostication of maxillary sinus cancer.

     

A case of recurrent esophageal cancer with lymph node and lung metastases, successfully treated with systemic chemotherapy and radiofrequency-ablation

We report a case of recurrent esophageal cancer with lymph node and lung metastases, successfully treated with systemic chemotherapy and radiofrequency-ablation(RFA). A 45-year-old man was diagnosed with thoracic esophageal cancer.Radical esophagectomy with three-field lymphadenectomy was performed.After 6 months, mediastinal lymph node recurrence occurred.Although the size of the recurrent mediastinal lymph nodes were reduced after 10 courses of systemic chemotherapy, two new lung metastatic nodules appeared in the right segments 8 and 9.CT -guided percutaneous RFA was successfully achieved for the 2 lesions.However, 6 months after the RFA, a local recurrence at the RFA site of segment 9 occurred, and an additional RFA was performed for this tumor.Five years and four months after the first operation, the tumor marker level remained within a normal range, and the patient is doing very well without any signs of recurrence. RFA appears to be an effective and minimally invasive technique for controlling local recurrence of esophageal cancer when combined with systemic chemotherapy.