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Biomedical subjects

C T Stafford

Publications and source records attributed to C T Stafford.

At least 19 recordsLinked to original sources
PubMed1997

Management of imported fire ant allergy: results of a survey.

BACKGROUND: Fire ant allergy is a significant health problem in the southern United States. Management of fire ant allergy is less clearly defined than management of allergy to the winged Hymenoptera. OBJECTIVE: To determine how fire ant allergy is managed by practicing allergists. METHODS: A survey form was developed and distributed to American College of Allergy, Asthma & Immunology members practicing in fire ant endemic states. Completed forms were returned to the American College of Allergy, Asthma & Immunology central office and forwarded to the authors for analysis. RESULTS: Three hundred twenty-nine of 879 (37.4%) surveys were returned; 81% of respondents have evaluated patients with imported fire ant allergy. Immunotherapy is used by 96.7% of respondents to treat fire ant allergy. A wide range of maintenance dosages are prescribed. Skin testing is the most common diagnostic method. Systemic reactions to stings while on maintenance immunotherapy were reported by 19%. Allergists utilize different criteria in consideration for stopping immunotherapy; 19% continue it indefinitely. CONCLUSIONS: There are many areas of general uniformity and other areas of divergence in how allergists manage imported fire ant allergy. These findings suggest continued need for further investigation regarding the efficacy, dosage, and duration of immunotherapy, as well as further elucidation of the natural history of fire ant allergy.

Ant Venoms↗
PubMed1996

Hypersensitivity to fire ant venom.

LEARNING OBJECTIVES: Reading this article will reinforce the reader's knowledge of the taxonomy, origin, and distribution of fire ants and will increase his ability to diagnose and manage reactions caused by the two imported species, Solenopsis invicta and richteri. This review will also enhance the reader's knowledge of the available diagnostic methods and therapeutic measures, including the role of fire ant venom versus whole body extract in the management of fire ant allergy. DATA SOURCES: Information for this review was obtained primarily from abstracts and articles written by investigators recognized for their expertise in fire ant venom research. STUDY SELECTION: References were selected based on their clinical applicability and relevance to the epidemiology and pathophysiology of imported fire ant hypersensitivity. CONCLUSIONS: The imported fire ant represents a significant health hazard for persons living in fire ant endemic areas in the southern United States. Sting reactions range from local pustules and large, late-phase responses to life-threatening anaphylaxis. Fire ant allergen-specific immunotherapy can reduce the risk of subsequent systemic reactions. Four important Sol i venom allergens have been isolated and characterized. Clinical studies have been designed to compare the safety and efficacy of fire ant venom with whole body extract for diagnosis and treatment of fire ant allergy.

Animals↗
PubMed1995

Laboratory evaluation of a commercial immunoassay for fire ant allergen-specific IgE antibodies.

BACKGROUND: In vitro testing for fire ant sensitization would be useful for research purposes and in special clinical situations. METHODS: Laboratory performance of a commercial assay (Pharmacia CAP System, [PCS]), for specific IgE to Solenopsis invicta whole body extract was studied in 46 persons. Assay results were compared with those of venom skin testing, RAST, and ELISA. The manufacturer's global cutoffs were compared with cutoffs set by using methods derived from analytical detection limit theory. RESULTS: Thirty-two study subjects had positive skin test results, and 14 had negative results. Raw PCS data demonstrated a high level of correlation with RAST (rho = 0.941) and ELISA (rho = 0.931), and showed good correlation with skin testing (rho = -0.769). Analysis of binormal receiver operating characteristic curves, using skin test results as the reference standard, demonstrated no difference in performance among the three assays. The fixed global quantitative cutoff of 0.35 kUa/L was relatively insensitive. Use of the manufacturer's qualitative alternate scoring method cutoff substantially increased sensitivity without loss of specificity, as did lower limit of detection set by use of diluent. CONCLUSIONS: In situations in which skin testing for fire ant sensitization is not feasible, PCS appears to be an acceptable in vitro alternative method for determination of fire ant allergen-specific IgE.

Allergens↗
PubMed1994

Development of an enzyme-linked immunosorbent assay for measurement of fire ant venom-specific IgE.

An enzyme-linked immunosorbent assay (ELISA) was developed for in vitro measurement of IgE specific for Solenopsis invicta venom. Enhanced binding microtiter plates were coated with S. invicta venom protein and incubated with sera from fire ant allergic patients and control subjects. Bound IgE was tagged with peroxidase-conjugated monoclonal anti-IgE and quantitated with the substrate/indicator system H2O2/tetramethylbenzidine. Absorbance (620 nm) represented venom-specific IgE values. The ELISA correlated well with the imported fire ant venom RAST (r = .87, P < .0001). Using skin test reactivity as the standard measure of venom-specific IgE, the venom ELISA appeared to be a sensitive in vitro assay comparable to venom RAST. ELISA is less expensive than RAST and does not require licensing or handling of radioisotopes.

Adult↗
PubMed1993

Allergy to insect stings. A need for improved preventive management.

Allergy to insect venom is a major health problem for a significant number of people. Immunotherapy can reduce the risk of subsequent reaction from about 60% to less than 5%. Standard preventive care should include (1) advice concerning avoidance of insects, (2) prescription of an epinephrine kit or syringe for self-administration (unless medically contraindicated), and (3) referral for evaluation. Results of several studies from various regions of the country raise concern about the preventive care and advice given these patients and suggest a need for continuing medical education to improve preventive management of allergy to insect stings.

Anaphylaxis↗
PubMed1992

Safety and efficacy of fire ant venom in the diagnosis of fire ant allergy.

Thirty-three adult patients who had had systemic allergic reactions to fire ant stings and 33 insect-nonallergic control subjects were skin tested with single lots of Solenopsis invicta (Sol i) fire ant venom (IFAV) and two commercially available imported fire ant whole body extracts (IFA WBEs). All three extracts were analyzed for protein concentration. Sol i II and Sol i III concentrations were each assayed by means of two ELISAs with complementary monoclonal antibodies, one species specific and one cross-reactive. Radioallergosorbent test (RAST) to IFAV and both IFA WBEs was performed on sera from all study subjects. Both IFA WBEs contained high concentrations of fire ant body proteins. Sol i II and III concentrations each varied twofold between the two IFA WBE preparations. Patients were generally more reactive to IFAV than IFA WBE by skin testing and RAST. IFAV RAST appeared to be a more sensitive assay than IFA WBE RAST. No adverse reactions occurred to skin testing with IFAV, but intradermal testing with higher concentrations of IFA WBE caused delayed large local reactions in 16 of 30 (53%) control subjects. These reactions were attributed to the large amounts of extraneous body proteins in IFA WBE. These results (1) demonstrate that skin testing with IFAV is safe, (2) indicate that IFAV is more potent than IFA WBE, and (3) suggest that IFAV may be the superior reagent for diagnosis of fire ant allergy.

Adult↗
PubMed1992

In vitro effects of interleukin-2 and gamma globulin on immune dysfunction in a patient with severe mucocutaneous herpes simplex virus infection.

A previously healthy woman developed severe, recurrent mucocutaneous herpes simplex virus (HSV) infection at 21 years of age. Immunologic assessment over the past 2 years has revealed persistent T-cell and natural killer cell dysfunction despite normal numbers of these cells as measured by flow cytometry. We studied the effect of recombinant interleukin 2 (rIL-2) and gamma globulin on the patient's mononuclear cells in 18-hour 51Cr release assays using HSV-infected and uninfected target cells. Both gamma globulin and rIL-2 significantly enhanced target cell lysis of HSV-infected target cells (P less than .001), but did not increase lysis of uninfected target cells. Addition of the patient's serum had no effect on HSV-infected target cell lysis despite a high HSV IgG titer, indicating a possible specific abnormality in production of antibody-dependent cellular cytotoxicity antibody.

Adult↗
PubMed1991

Modification of the fluorescent allergosorbent test as an inhibition assay for determination of cross-reactivity among aeroallergens.

The fluorescent allergosorbent test was adapted as an inhibition assay to determine cross-reactivity between aeroallergens. With this method, similar antigenic determinants were found between short ragweed and giant ragweed, cocklebur, lamb's-quarter, rough pigweed, marsh elder, and goldenrod. Cocklebur and giant ragweed were highly potent in their ability to competitively bind to short ragweed IgE. The other pollens demonstrated lower potency of cross-reacting antigens. The fluorescent allergosorbent test-inhibition assay appears to be a useful method to determine cross-reactivity among aeroallergens.

Binding, Competitive↗
PubMed1990

The clinician's view of sinusitis.

Widespread underdiagnosis and inadequate treatment of acute sinusitis may be inferred from the prevalence of chronic sinusitis in the United States. Thus the otolaryngologist's role in the management of sinusitis goes beyond treatment of referred patients. It also includes the responsibility to educate referring physicians in improved diagnostic methods and earlier, more effective forms of therapy. While antral puncture is the sine qua non for determining specific diagnosis, standard radiographs and sound clinical judgment may offer practical alternatives. Early, aggressive antibiotic therapy (with ampicillin, amoxicillin, amoxicillin-clavulanate potassium, or appropriate cephalosporins), plus oral decongestants for symptomatic relief, provides therapeutic efficacy for acute sinusitis and should be considered the initial step toward prevention of chronic sinusitis.

Anti-Bacterial Agents↗
PubMed1990

Comparison of in vivo and in vitro tests in the diagnosis of imported fire ant sting allergy.

The specificities and sensitivities of skin test reactivity to imported fire ant (IFA) whole body extract (WBE) and IFA venom were compared with IFA WBE RAST and IFA venom RAST in the diagnosis of IFA allergy. Study groups consisted of 18 IFA allergic patients and 21 control subjects with no history of allergy to insect stings. All IFA allergic patients had positive skin tests to both IFA WBE and IFA venom. Six of 21 (29%) control subjects also had positive skin tests to both IFA WBE and IFA venom. A commercial IFA WBE RAST was positive in 10 of 18 (56%) IFA-allergic patients and 2 of 21 (10%) control subjects. Imported fire ant aqueous venom RAST was positive in 11 of 11 (100%) IFA-allergic patients and three of ten (30%) control subjects. Vespa IFA venom RAST was positive in 16 of 18 (89%) IFA-allergic patients and 5 of 21 (24%) controls. The sensitivities and specificities of IFA WBE skin testing, IFA venom skin testing, and IFA venom RAST did not differ significantly. Imported fire ant WBE RAST was less sensitive than the other diagnostic methods.

Adolescent↗
PubMed1989

Survey of fatal anaphylactic reactions to imported fire ant stings. Report of the Fire Ant Subcommittee of the American Academy of Allergy and Immunology.

A physician questionnaire survey was conducted by the Fire Ant Subcommittee of the American Academy of Allergy and Immunology to document deaths caused by imported fire ant stings. From the 29,300 physicians surveyed, reports of 83 fatal and two near-fatal fire ant-sting reactions were received. Most anaphylactic deaths were reported from Florida (22) and Texas (19). After excluding duplicate reports, four confirmed deaths were documented in Alabama, 10 in Florida, two in Georgia, two in Louisiana, and 14 in Texas.

Adult↗
PubMed1989

Survey of whole body-extract immunotherapy for imported fire ant- and other hymenoptera-sting allergy. Report of the Fire Ant Subcommittee of the American Academy of Allergy and Immunology.

A survey of 5300 allergists was conducted to determine the number and geographic distribution of patients receiving immunotherapy for imported fire ant (IFA) allergy in the United States and Canada. Responses were received from 1293 physicians who reported a total of 2573 patients being treated in 28 states. Most patients were from the southeast, but some patients were reported to be receiving IFA immunotherapy in areas outside the boundaries of known IFA infestation. Although IFA is a widespread health hazard in the southeast, it appears to exert an uneven impact on allergy practice in this region. Of the 1293 physicians responding to the survey, 117 (9%) reported the use of whole body extract (WBE) in the treatment of 1746 patients with winged Hymenoptera-sting allergy. Continued use of WBE immunotherapy was reported by physicians from all regions of the United States and from Canada. The largest numbers of patients receiving winged WBE immunotherapy were reported from Texas (641), Pennsylvania (246), Florida (129), and Canada (127). The results of this survey suggest a need for continuing medical education regarding (1) the magnitude of the health hazard posed by the IFA and (2) the efficacy of venom versus WBE in the treatment of winged Hymenoptera-sting allergy.

Animals↗
PubMed1989

Life-threatening allergic reactions. Anticipating and preparing are the best defenses.

The sudden development of anaphylaxis or an anaphylactoid reaction is a medical emergency. It can cause death from upper airway edema and asphyxia, especially if the patient is at high risk (eg, has cardiac disease or bronchial asthma) and does not seek prompt attention or know how to administer self-treatment. Among the most common causes are administration of certain drugs and biologic agents, exposure to radiographic contrast media, ingestion of particular foods (eg, shellfish, nuts), and insect stings. Dr Stafford describes clinical manifestations of severe allergic reactions that aid in its diagnosis, the many possible causes, a treatment protocol, and preventive measures.

Anaphylaxis↗