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Epic Code LAB3156 Schistosoma species Antibody, IgG, Serum

Additional Codes

Mayo code: BILHA

Epic code: LAB 3156

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Detection of antibodies to Schistosoma species

Specimen Type

Serum


Specimen Required


Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 1 mL


Laboratory Test Directory Note:

COLLECTION NOTE: Volumes listed are in serum or plasma, draw approximately 2 1/2 times the requested volume in whole blood.

Specimen Minimum Volume

0.5 mL

Forms

If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.

Highlights

This assay can be used as a screening test for detection of antibodies to Schistosoma species.

 

Positive results should be interpreted alongside clinical findings and suitable exposure history.

 

A single negative result should not be used to rule-out Schistosoma infection.

 

False-positive results may occur in individuals with other helminth infections.

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 30 days
  Frozen  30 days

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Heat inactivated Reject

Cautions

This assay is designed to specifically detect IgG-class antibodies to Schistosoma mansoni, which are likely cross-reactive to other Schistosoma species.

 

Sensitivity for detection of antibodies to each of the Schistosoma species has not been evaluated for this assay.

 

Patients may remain seropositive by this assay following appropriate treatment and clearance of the infection.

 

Positive results should be confirmed with other laboratory findings (eg, ova and parasite examination), clinical symptoms, and suitable exposure history.

Clinical Information

Schistosoma species (class Trematoda) are flukes, characterized by their flat, leaf-like morphology as adults, and use of gastropod mollusks (eg, snails) as an intermediate host. The schistosomes are also referred to as the "blood flukes," of which there are 5 species known to infect humans: Schistosoma mansoni, Schistosoma japonicum, Schistosoma haematobium, Schistosoma mekongi, and Schistosoma intercalatum. Among these S mansoni, S japonicum and S haematobium are most common.

 

These species have a defined geographic distribution, with S mansoni occurring throughout sub-Saharan Africa, the Middle East, and islands in the Caribbean; S haematobium found in much of the African continent and the Middle East; and S japonicum localized to China, Indonesia, and the Philippines.

 

Humans are definitive hosts for all of the Schistosoma species except for S japonicum, and infection begins with skin penetration of cercariae in contaminated water sources. The cercariae shed their bifurcated tails, becoming schistosomulae and migrate through the vascular system to the lungs, heart, and the portal venous system in the liver. There they mature to adults, pair off and migrate to the mesenteric venules of the bowel and rectum (S mansoni, S japonicum) or venus plexus of the bladder (S haematobium). Females will shed eggs, which are moved progressively towards the lumen of the intestine (S mansoni, S japonicum) and bladder (S haematobium) and are eliminated in the feces or urine, respectively. These eggs will hatch under ideal conditions, releasing miracidia, which penetrate specific snail (mollusk) intermediate hosts and develop into cercariae, continuing the life cycle.

 

While many infections are asymptomatic, acute schistosomiasis (Katayama fever), due to S mansoni or S japonicum, may occur weeks after initial infection. Symptoms include fever, cough, abdominal pain, diarrhea, hepatosplenomegaly, and eosinophilia. Central nervous system infection is uncommon; however, cerebral granulomatous disease may be caused by migration of Schistosoma eggs into the brain or spinal cord. Cystitis and ureteritis with hematuria are associated with S haematobium infection and can progress to bladder cancer.

 

Diagnosis of schistosomiasis can be made by detection of eggs in fecal or urine samples as appropriate for each species. Antibody detection can be useful for patients who reside in nonendemic areas but have recently traveled to regions where Schistosoma species are found, and in whom eggs cannot be identified in fecal or urine examinations.

Method Name

Enzyme Immunoassay (EIA)

Report Available

Same day/1 to 5 days

Reporting Name

Schistosoma Ab, IgG, S

Reference Values

Negative

Interpretation

Negative: No IgG antibodies to Schistosoma species detected.

 

Equivocal: Recommend follow-up testing in 10 to 14 days if clinically indicated.

 

Positive: IgG antibody to Schistosoma species detected. Differentiation between Schistosoma species is not possible by this assay. Serologic cross-reactivity may occur in individuals with other helminth infections, including with Echinococcus or Taenia species.

Method Description

The qualitative immunoenzymatic determination of IgG-class antibodies against Schistosoma mansoni is based on the ELISA technique.

 

Microtiter strip wells are precoated with Schistosoma mansoni antigens to bind corresponding antibodies of the specimen. After washing the wells to remove all unbound sample material, horseradish peroxidase (HRP)-labelled Protein A conjugate is added. This conjugate binds to antigen-antibody complexes. The immune complex formed by the bound conjugate is visualized by adding tetramethylbenzidine (TMB) substrate, which gives a blue reaction product.

 

The intensity of this product is proportional to the amount of Schistosoma-specific IgG antibodies in the specimen. Sulfuric acid is added to stop the reaction. This produces a yellow endpoint colour. Absorbance at 450 nm is read using an ELISA microwell plate reader.(Package insert: NovaLisa Schistosoma mansoni, NovaTec Immundiagnostica GmbH; 05/2017)

Day(s) Performed

Tuesday, Thursday

Clinical Reference

1. Jones MK: Recent advances in diagnosis of human schistosomiasis. Asia Pacific J Trop Med. 2008;2:63-68

2. Gary DJ, Ross AG, Li YS, McManus DP: Diagnosis and management of schistosomiasis. Br Med J. 2011;342:d2651

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

86682

LOINC Code Information

Test ID Test Order Name Order LOINC Value
BILHA Schistosoma Ab, IgG, S 33317-9

 

Result ID Test Result Name Result LOINC Value
BILHA Schistosoma Ab, IgG, S 33317-9