Immunodiagnosis of human parasitosis. I. Overview

Various methods with either cellular or humoral basis employed in the diagnosis of human parasitoses are reviewed. Using different methods and techniques humoral antibodies have been increasingly detected. Recently antigen research is becoming important, either in the acute phase of infection or in the immunocompromised host.     

Experimental pulmonary nocardiosis in monkeys.

The study describes an easy and reproducible technique of producing pulmonary nocardiosis in monkeys, yielding consistent morbidity and mortality results. Introduction of the fungal suspension into the lower canaliculus, with or without debridement of the canalicular epithelium, produced fatal pneumonitis in 1-2 weeks. Specificity of the lesions was determined by demonstration of Nocardia in tissue sections and in culture.     

Immunodiagnosis of Candida-infections. I. Sensitivity of the antigens

Attemps were made to prepare a sensitive antigen from C. albicans suitable for detecting humoral antibodies and hypersensitivity in deep-seated candidiasis, in patients at risk of invasive candidiasis and in allergic states caused-by Candida.5343 persons suffering from systemic, bronchial, vaginal candidiasis, bronchial asthma, chronic bronchitis, polyarthritis nodosa, ulcus cruris, malignancy, rhinitis pollinosa, vasomotorica, and non infected miners, farmers and blood donors were investigated on the presence of antibodies and hypersensitivity against 8 different antigen preparations.The extracellular protein and mannan- protein isolated from the cultivation medium of C. albicans proved the most sensitive for specific anticandida antibodies. The mannan, especially the mannan isolated from the cell surface of C. albicans determined best for the allergy.Comparison made of commercial Candidine showed similar activity. The whole cell C. albicans antigen as well as the mixed Candida antigen reacted much weakly.Comparison made of autoantigen, C. albicans and mixed C. albicans antigen proved the highest sensitivity of the autoantigen.     

Immunodiagnosis of Snake Bite

Management of a patient with snake bite is influenced by the nature of the offending snake. Species diagnosis based on the patient''s history and physical signs is often unreliable and the possibility of making a species diagnosis by immunological means has therefore been investigated. Wound aspirates, blister fluids, sera, and urine samples from patients with snake bite were examined for the presence of species-specific venoms using immunodiffusion. A positive species diagnosis was made in 40 out of 101 patients. Immunodiagnosis was especially successful in patients bitten by the puff adder, Bitis arietans, and the African spitting cobra, Naja nigricollis. A higher success rate could probably be achieved using more specific antisera and more sensitive assay techniques.     

Immunodiagnosis of childhood malignancies

Immunodiagnosis utilizing immunohistochemical techniques is currently the most commonly utilized and readily available method of ancillary diagnosis in pediatric oncopathology. The methodology comprises relatively simple steps, based on straightforward biologic concepts, and the reagents used are generally well characterized and widely used. The principle of cancer immunodiagnosis is based on the determination of neoplastic lineage using detection of proteins typical of cell differentiation pathways. Methodology sensitivity varies and has become greater with each new generation of tests, but technical drawbacks should be considered to avoid excessive background or nonspecific results. Automated instrumentation offers a degree of accuracy and reproducibility not easily attainable by manual methods.     

Immunodiagnosis of sexually transmitted disease

Methods for detecting microbial antigens in clinical specimens offer an alternative to culture in the diagnosis of some sexually transmitted diseases. Developers of the immunologic methods are faced with a number of problems in evaluating the new tests. Traditionally, these tests are compared to culture as the "gold standard." Unfortunately, culture for Neisseria gonorrhoeae or Chlamydia trachomatis--the two agents most commonly sought--is considerably less sensitive than 100 percent. Immunologic methods may appear to produce false positives when the paired specimens are actually false-negative cultures. Another source of discordant results is sampling variation. These considerations, however, will not account for all false-positive results. Even the best non-culture methods have a low rate of false-positive results. If a new test has a specificity of 97 percent, it, by definition, yields approximately 3 percent false-positive reactions. In low-prevalence settings this false-positive rate will create problems in interpreting the results. For example, in a population with 3 percent prevalence of infection, a positive result in a 97 percent specificity test could only have a predictive value of 50 percent. Most testing for STD agents is performed in low-prevalence settings. None of the currently available immunodiagnostic procedures has a performance profile that suggests it will be satisfactory for diagnostic use in the low-prevalence setting.     

Immunodiagnosis of IgD multiple myeloma. A report of 17 cases

The present report summarizes the main clinical and immunochemical features of 17 patients with IgD myeloma and compares than with the evidence reported in the literature. The difficulties inherent in the immunodiagnosis of this disease, particularly in detection of the M-component, typing of IgD and demonstrating its monoclonal nature, are discussed on the basis of personal observations and those of other investigations. Special emphasis is placed on clinical and immunochemical characteristics of IgD kappa myeloma. Immunoquantitation of serum IgD is considered to be the most reliable method of immunodiagnosis.     

Immunodiagnosis of human trichinellosis using excretory-secretory (ES) antigen.

Infective first stage larvae of Trichinella spiralis were recovered from muscles of laboratory infected mice by digesting the muscles with 1% HC1-1% pepsin and collecting the larvae by modified Baerman's method. The larvae were cultivated in a serum-free medium for 18 h. The ES antigen obtained from the culture medium was used in an enzyme-linked immunosorbent assay (ELISA) for detecting IgG antibodies to T. spiralis in serum samples collected from three groups of individuals. The individuals of the first group were parasitologically confirmed trichinellosis patients, while those of group 2 were patients with other helminthiasis and group 3 were healthy, parasite-free individuals. The specificity of the assay was 100%. The sensitivity of the test was also 100% when performed on sera of group 1 collected at days 57 and 120 after infection. Sera collected earlier (day 23) and those collected 700 days after infection had negligible reactivity. Thus IgG-ELISA using ES antigen of the L1 was useful not only for diagnosis but also in evaluation of cure. Western blot analysis revealed that specific antigens of T. spiralis were 94, 67, 63, and 39 kilodalton components.