Viswanath P. Kurup

Skin and serologic testing in the diagnosis of latex allergy

BACKGROUNDnLatex hypersensitivity is associated with occupational allergy, contact urticaria, rhinitis, asthma, and anaphylaxis. However, standardized sensitive and specific latex extract for skin prick or serologic testing is not available in the United States.nnnMETHODSnWe investigated the reliability of two latex extracts in 118 consecutive skin tests in patients with spina bifida, health care workers, and other patients with symptoms of latex allergy, and 10 control subjects.nnnRESULTSnForty-two of 86 patients with spina bifida, 11 of 15 health care workers with symptoms of latex allergy, 6 of 7 patients with symptoms of latex allergy, and 0 of 10 control subjects had demonstrable immediate wheal and flare responses to latex prick testing. In addition, 95 patients and 10 control subjects were tested concurrently for latex-specific IgE by ELISA. Of 55 patients with positive skin prick test results, 48 were reactive as determined by ELISA for IgE-specific latex antibody (sensitivity = 87%). Latex ELISA titers were significantly higher in patients with positive skin prick test results with a history of anaphylaxis to latex and in individuals without symptoms of latex allergy who had positive skin prick test results when compared with patients with negative skin prick test results. During the skin test procedure, nine patients had adverse reactions, including anaphylactic reactions in four.nnnCONCLUSIONSnSkin prick and serum testing are reliable methods of diagnosing latex allergy. Serologic evaluation may be more desirable until allergen standardization is available.

The diagnosis of natural rubber latex allergy

Allergy to latex is a rapidly emerging public health problem. Because our knowledge of the major allergens involved is incomplete, standardized in vivo and in vitro tests have not been available. Because of systemic reactions to skin prick testing, this method should be used only after results of other tests have been inconclusive. Risks and benefits of the test need to be explained to the patient, and until standard extracts of latex are available, skin tests should be performed under a research protocol. We anticipate that with greater knowledge of the relevant allergens, purification of these allergens with affinity chromatography, high-performance liquid chromatography, and monoclonal antibodies, a safe and reliable extract will be available in the near future for skin testing. Until then, the above guidelines can serve clinicians in their daily practice in the diagnosis of latex allergy.

Marijuana smoking and fungal sensitization

The possible role of marijuana (MJ) in inducing sensitization to Aspergillus organisms was studied in 28 MJ smokers by evaluating their clinical status and immune responses to microorganisms isolated from MJ. The spectrum of illnesses included one patient with systemic aspergillosis and seven patients with a history of bronchospasm after the smoking of MJ. Twenty-one smokers were asymptomatic. Fungi were identified in 13 of 14 MJ samples and included Aspergillus fumigatus, A. flavus, A. niger, Mucor, Penicillium, and thermophilic actinomycetes. Precipitins to Aspergillus antigens were found in 13 of 23 smokers and in one of 10 controls, while significant blastogenesis to Aspergillus was demonstrated in only three of 23 MJ smokers. When samples were smoked into an Andersen air sampler, A. fumigatus passed easily through contaminated MJ cigarettes. Thus the use of MJ assumes the risks of both fungal exposure and infection, as well as the possible induction of a variety of immunologic lung disorders.

Allergenic fungi and actinomycetes in smoking materials and their health implications

Street marijuana, commercial cigarettes and pipe tobaccos were studied for the presence of fungi and actinomycetes associated with hypersensitivity pneumonitis. Aspergillus species and thermophilic actinomycetes were isolated from the smoking materials. In addition, Aspergillus fumigatus spores were isolated from marijuana smoke, indicating the potential hazard involved in developing serious disease. Precipitin antibodies against fungi, particularly Aspergillus, showed a higher prevalence in marijuana smokers, whereas only very few cigarette smokers and nonsmokers demonstrated antibodies to fungi. Cigarette smokers and nonsmokers showed more or less similar prevelance of antibodies against thermophilic actinomycetes.

Immunologic cross-reactions among thermophilic actinomycetes associated with hypersensitivity pneumonitis

Antibodies produced in rabbits against Micropolyspora faeni, Thermoactinomyces vulgaris, T. sacchari, Thermoactinomyces candidus, and Saccharomonospora viridis were tested against antigens derived from many strains of thermophilic actinomycetes for precipitating antibodies by immunodiffusion test. It was found that immune sera reacted strongly against antigens from strains belonging to the same species and weakly against antigens from different species of thermophilic actinomycetes. However, sera from farmers lung patients showed cross-reactivity against antigens from different species. This may be because the patient is sensitized to multiple species of thermophilic actinomycetes present in the environment and developed antibodies against most of them.

Immunologic response to Faenia rectivirgula (Micropolyspora faeni) in a dairy farm family

In the present study, cellular and humoral responses to Faenia rectivirgula antigens were evaluated in seven subjects, members of a family who lived and worked on a dairy farm. Four subjects had clinical features of hypersensitivity pneumonitis after exposure to moldy hay. The other three subjects had no clinical disease in spite of similar exposure. Although serum precipitins were found in most subjects, a biotin-avidin-linked immunosorbent assay revealed high levels of F. rectivirgula-specific antibodies only in the symptomatic subjects. In addition, numerous precipitin arcs were present in the sera of the symptomatic but not the asymptomatic subjects by antigen-antibody crossed immunoelectrophoresis. No clear distinction between symptomatic and asymptomatic subjects could be made on the basis of lymphocyte phenotype studies, and antigen-induced lymphocyte transformation was not detected in any subjects. The results indicate that F. rectivirgula-specific antibody levels as detected by biotin-avidin-linked immunosorbent assay and by the presence of precipitin arcs in crossed immunoelectrophoresis may differentiate symptomatic and asymptomatic farmers.

Immune Response among Patients Exposed to Molds

Macrocyclic trichothecenes, mycotoxins produced by Stachybotrys chartarum, have been implicated in adverse reactions in individuals exposed to mold-contaminated environments. Cellular and humoral immune responses and the presence of trichothecenes were evaluated in patients with mold-related health complaints. Patients underwent history, physical examination, skin prick/puncture tests with mold extracts, immunological evaluations and their sera were analyzed for trichothecenes. T-cell proliferation, macrocyclic trichothecenes, and mold specific IgG and IgA levels were not significantly different than controls; however 70% of the patients had positive skin tests to molds. Thus, IgE mediated or other non-immune mechanisms could be the cause of their symptoms.

Variability of extracts used in immunoprecipitin tests.

Immunodiffusion reactions of several different commercial fungal extracts from organisms were compared to those obtained from patients environments. Sera were obtained from patients suspected of having hypersensitivity lung disease (HLD). There was a difference in reactivity among the sources of the antigen and in some lots of antigen from the same commercial supplier. The results demonstrate a wide variation in the reactivity of different antigenic extracts and emphasize the need for uniform standardization of preparations used in precipitin tests.

Aspergillus antigens associated with allergic bronchopulmonary aspergillosis.

Among the molds causing allergy, Aspergillus fumigatus (Af) constituted a major species present both indoors and outdoors. The antigens both secreted and bound to hyphae and conidia have been isolated for immunodiagnosis of allergic aspergillosis. The crude extracts have been used to demonstrate IgE antibody in vitro and for skin testing. The crude extracts contain many antigenic and non-antigenic components and toxins and have demonstrated inconsistent reactivities. In addition, similarity with other allergens also may complicate specific diagnosis. A number of methods including conventional purification and fractionation methods have been used to obtain relevant antigens. In recent years, monoclonal antibody dependent affinity purification and molecular biology methods have obtained considerable progress in the allergen purification and in developing specific and reliable immunoassays. However, international standards are still lacking and hence, comparison of results among laboratories are not possible yet.

Characterization of some members of the genusThermomonospora

Twenty strains ofThermomonospora, isolated from the environments of patients with hypersensitivity pneumonitis or received from culture collections or other workers, were studied for their detailed morphological, physiological, and immunological characteristics. The species studied includedThermomonospora fusca, T. alba, T. curvata, T. mesophilia, andT. mesouviformis. The results indicate that several species can be differentiated by various criteria studied; however, two species,T. fusca andT. alba, could not be separated from one another by any of the tests or methods used in the study.