Safety, False-Positive Reactions and Sensitizing Properties of Leishmania Tropica Skin Test Antigen
Condition: Cutaneous Leishmaniasis
MeSH terms: Leishmaniasis; Leishmaniasis, Cutaneous
Intervention: Leishmania tropica Skin Test Antigen (LtSTA); Leishmania tropica Skin Test Antigen Placebo (Placebo)
Intervention description: Administer 15 ug, 30 ug or 50 ug of LtSTA into DTH positive volunteers. Repeat drug administration 30 days after initial injection and 60 days after initial injection. Read and interpret reaction 48 hours after each injection. Observe subjects for conversion or adverse reaction.; Administer Placebo concurrently with 15 ug, 30 ug and 50 ug doses of LtSTA. Read and interpret the reaction 48 hours after injection. Observe subjects for reaction to Placebo
Phase: Phase 2
Study type: Interventional
Primary purpose: Screening
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Enrollment: 50.0
Sex: All
Minimum age: 18 Years
Maximum age: 60 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: Leishmaniasis; Delayed-Type Hypersensitivity (DTH); Skin Test; Conversion; Prior exposure to Leishmania major

Summary:

      The efficacy of LtSTA as a skin test antigen depends upon the sensitivity and specificity of
      the product. This study has been designed to measure the skin test responses to 15, 30, or
      50µg doses of LtSTA. The measurements of non-specific reactivity due to components of the
      antigen solution and the product's ability to sensitize lymphocytes of Leishmania naïve
      persons when administered intradermally. The presence or absence of a local inflammatory
      response to the first skin test with each of three doses of LtSTA will provide insight on the
      specificity of the antigen in a naïve population. The local inflammatory response to LtSTA
      following the first and second repeat skin tests will indicate if the antigen is sensitizing
      after intradermal administration.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Male or Female in good health;

          -  Age 18 - 60 years;

          -  No past history of leishmaniasis or prior participation in a Leishmania study;

          -  No prior skin test with a Leishmania antigen;

          -  No occupational, residential, or travel exposure to Leishmania;

          -  Positive Candin® or Trichophyton skin test (>= 5 mm induration).

        Exclusion Criteria:

          -  History of adult atopic dermatitis, contact dermatitis to multiple agents, unexplained
             urticaria, or asthma;

          -  Active allergic rhinitis or conjunctivitis;

          -  History of allergy or reactions to phenol, polysorbate 80, or glycerol;

          -  Medications: currently taking (within the last month) antihistamines or recent history
             of taking (within the last 1 year) corticosteroids, immunosuppressants;

          -  Splenectomy;

          -  Active medical disease*;

             *Active Medical Disease: Any active physical or psychiatric condition that may
             increase the risks associated with participation in the study or interferes with the
             interpretation of study results. Included chronic medical illnesses are cardiovascular
             disease, renal insufficiency, chronic respiratory illness, cirrhosis, chronic
             hepatitis, chronic pancreatitis, chronic diarrhea, malnutrition, malignancy,
             autoimmune disease, and asthma.

          -  Pregnancy or lactating;

          -  Immunization within 4 weeks;

          -  History of leishmaniasis;

          -  Occupational exposure to Leishmania;

          -  Prior participation in a Leishmania study;

          -  Prior skin test with Leishmania antigen;

          -  Travel history to Leishmania endemic areas;

          -  Abnormal screening lab results;

          -  Keloid scar formation