TEST CATALOG ORDERING & RESULTS SPECIMEN HANDLING CUSTOMER SERVICE EDUCATION & INSIGHTS
Test Catalog

Test ID: LEIS    
Leishmaniasis (Visceral) Antibody, Serum

Useful For Suggests clinical disorders or settings where the test may be helpful

Aiding in the diagnosis of active visceral leishmaniasis

 

This test should not be used as the sole criteria for diagnosis

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Visceral leishmaniasis (kala azar) is a disseminated intracellular protozoal infection that targets primarily the reticuloendothelial system (liver, spleen, bone marrow) and is caused by Leishmania donovani, Leishmania chagasi, or Leishmania infantum (L donovani complex).

 

Transmission is by the bite of sandflies. Clinical symptoms include fever, weight loss, and splenomegaly; pancytopenia and hypergammaglobulinemia are often present. Most (90%) new cases each year arise in rural areas of India, Nepal, Bangladesh, Sudan, and Brazil, but the disease has a worldwide distribution, including the Middle East.

 

Definitive diagnosis has required the microscopic documentation of characteristic intracellular amastigotes in stained smears from culture of aspirates of tissue (spleen, lymph node) or bone marrow. The detection of serum antibodies to the recombinant K39 antigen of L donovani is an alternative noninvasive sensitive (95%-100%) method for the diagnosis of active, visceral leishmaniasis.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Negative

Reference values apply to all ages.

Interpretation Provides information to assist in interpretation of the test results

Negative:

Negative results indicate the absence of antibodies to members of the Leishmania donovoni complex. Repeat testing in 2 to 3 weeks if clinically indicated. Immunocompromised patients frequently have low or undetectable antibodies to Leishmania species.

 

Positive:

Positive results indicate the presence of antibodies to members of the L donovoni complex, the causative agents of visceral leishmaniasis. Results should not be used as the sole criterion for diagnosis or treatment of visceral leishmaniasis and should not be used to diagnose other forms of leishmaniasis. False-positive reactions due to malaria infection have been reported.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

This test indicates only the presence of antibodies and should not be used as the sole criteria for diagnosis.

 

False-positive results may occur in patients with malaria or in the presence of rheumatoid factor.

 

Specimens containing glycerol or other viscous materials may interfere with the test.

 

Patients coinfected with HIV and Leishmania may fail to produce antibodies.

Supportive Data

Manufacturer's reported sensitivity and specificity (for endemic areas) are 90% or more and 93% to 100% respectively (InBios Kalazar Detect Rapid Test product insert). Validation studies in the Mayo Clinic Division of Clinical Microbiology provided a sensitivity of 94% (panel of 16 known positives) and specificity of 100% (panel of 50 normal blood donors plus 16 positives for other parasitic infections).

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Sundar S, Sahu M, Mehta H, et al: Noninvasive management of Indian visceral leishmaniasis: clinical application of diagnosis of K39 antigen strip testing at a kala-azar referral unit. Clin Infect Dis. 2002;25:581-586

2. Aronson NE, Copeland NK, Magill AJ: Leishmania species: visceral (Kala-Azar), cutaneous, and mucosal leishmaniasis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Elsevier; 2020:3321-3339