Immunofluorescence study of skin rash in patients with dengue hemorrhagic fever.

Fifty-three skin biopsy specimens obtained from the cutaneous rashes of patients who had dengue hemorrhagic fever (DHF) were studied by immunofluorescence technique. Six specimens showed deposits of IgM, beta 1 C-globulin, dengue antigen, and fibrinogen during the first week of fever. Some but not all of these components (IgM, beta 1 C, dengue antigen) were demonstrated in 29 specimens. Twenty-three of them yielded negative results. Granular deposits of IgM and beta 1 C appeared in the blood vessel walls of dermal papillae. Dengue antigen was seen in mononuclear cells that were closely infiltrated around the blood vessel wall in dermal papillae. Fibrinogen was located within or about the blood vessels. The findings suggest that the cutaneous rashes occurring in DHF are caused by an immunopathologic process.     

An immunofluorescence study of cerebral malaria. A correlation with histopathology

Histopathologic and immunopathologic features of cerebral malaria have been defined in a study of six autopsy cases with severe Plasmodium falciparum infection. In five cases, immunofluorescent studies demonstrated intense deposition of P falciparum antigen, IgG, and fibrin in cerebral vessels associated with the histopathologic finding of hemorrhage in the white matter of cerebrum and cerebellum regardless of the presence of parasitized erythrocytes in the cerebral vessels. Immunofluorescent study also demonstrated the extravascular deposits of P falciparum granular antigen associated with acute inflammatory lesion in cerebral tissue in one case. These findings suggested that the immunopathogenic mechanism may in some way play a role in the pathogenesis of cerebral malaria.     

Detection of antibodies in sera from patients with Opisthorchiasis

The indirect immunofluorescent antibody technique (IFA) was used for detection of antibodies in sera of patients with Opisthorchiasis. Antibodies to fluke worm and egg antigens were detected in 166 of 205 (81%) patients. The test showed that only the IgG class of antibodies reacting exclusively with integumental wall of the worm (AW) were positive in 46.8% (96/205), reacting only with the wall of intact eggs in 11 out of 205 (5.4%) and antibodies to both fluke and their egg antigens were present in 28.8% (59/205). In addition, 5.4% (11/205) of patients' sera were positive for autoantibodies producing a speckled antinuclear antibodies (ANA) pattern. The sera positive for only AW contained detectable autoantibodies to other cell antigens including: anti-smooth muscle antibodies of 9.4% (9/96), antimitochondrial antibodies of 3.1% (3/96), anti-liver/kidney microsomes of 1% (1/96) and anti-parietal cell antibodies of 1% (1/96). Autoantibodies were undetectable in sera from normal subjects. Among the ANA positive sera, 55% (6/11) exhibited antibodies against an extractable nuclear antigen (ENA) by a tanned red cell hemagglutination assay. This finding may suggest that the autoantibody response was due to the cross reaction between worm antigen and self antigen or it may be the result of polyclonal activation of B lymphocytes in these patients.     

Identification and potential use of a soluble tumor antigen for the detection of liver-fluke-associated cholangiocarcinoma induced in a hamster model

A liver-fluke-associated cholangiocarcinoma (CCA), comparable to that occurring in humans, was induced by exposing Opisthorchis viverrini-infected hamsters to dimethylnitrosamine (DMN). Tumor masses were removed and histopathologically identified, then one portion was extracted for antigens used in the production of monoclonal antibodies (MAbs). The remaining portions were used to establish CCA cell lines. The antigens produced and secreted by these cell lines, as well as those originally present in the tissue extracts, possessed a 200-kDa glycoprotein that appeared to be immunologically distinct from other tumor markers. A specific MAb called 6E5 was used to set up a sandwich ELISA for the quantification of this antigen in the serum and bile of tumor-bearing animals. The assay system was sensitive enough to detect the antigen at concentrations below 10 ng/ml. The serum and biliary levels of this antigen were markedly elevated in animals with progressive tumors when compared with untreated controls. The serum taken serially from each animal that subsequently developed CCA showed a gradual but significant elevation of the antigen as carcinogenesis progressed. A few isolated animals exhibited a slight elevation of the antigen at a time as early as the end of DMN treatment, when the CCA should not yet have developed, judging from microscopic examination. The data from this animal model suggested that the CCA-associated soluble antigen defined by MAb 6E5 was a useful marker for the detection of tumors at an early stage of development.     

IgA nephropathy associated with enteric fever

3 cases of enteric fever (2 paratyphoid and 1 typhoid) associated with IgA nephropathy were reported. Salmonella Vi antigen was demonstrated in the glomeruli. The clinical syndrome disappeared after enteric fever was treated. Possible pathogenesis was discussed relating this intestinal infection to IgA nephropathy.     

Circulating immune complexes in serum from patients with dengue haemorrhagic fever.

Circulating immune complexes were detectable in 80% of serum from patients with dengue haemorrhagic fever. The immune complexes were detected for the first time on day two after the onset of the fever. The amount of complexes reached the maximum value on day 4 or 5 after onset, or when the patients developed shock or subsidence of fever, after which the complexes decreased in number. The number of complexes also correlated well with the clinical grading (severity) of the disease, i.e. the maximum amount was shown in grade III. These complexes may play a part in the pathogenesis of this disease.     

Immunopathology of acute rheumatic fever and rheumatic heart disease. The demonstration of Coxsackie group B viral antigen in the myocardium

Immunopathologic studies were performed on heart tissue of patients with acute rheumatic fever with carditis and chronic rheumatic heart disease. Coxsackie group B viral antigen was demonstrated in 3 heart specimens of patients clinically compatible with active rheumatic fever. In two of these the pathologic findings were compatible with acute rheumatic carditis. Immunoglobulin was detected in 2 and complement in one of these heart specimens. All of the chronic rheumatic heart specimens and the controls were negative. These findings suggested that Coxsackie group B virus may be etiologically related to the pathogenesis of acute rheumatic fever.     

A characteristic immunoblotting pattern for Opisthorchiasis sera with metacercarial antigens.

The protein compositions of homogenized metacercaria and adult Opisthorchis viverrini were characterized by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The two different stages of O. viverrini parasite contained several protein components with very similar mobilities on SDS-PAGE gel. The reaction in immunoblots of sera from patients with opisthorchiasis demonstrated antibodies against heterogeneous protein components of metacercariae and adult O. viverrini parasites. Only the components of metacercariae with molecular weights of 190-200 kD, 132 kD and 107 kD reacted specifically with opisthorchiasis sera. This characteristic reaction pattern was not observed in any control sera of normal subjects or those infected with other parasites. Identical reactions were however also recognized in the sera of experimental infected hamsters with metacercariae, but did not occur with adult worm as the antigen for the immunoblotting reaction. This may indicate that these metacercariae-associated protein components have potential diagnostic value for opisthorchiasis.