Lab Test

DNase-B Antibody

Dnase B Antibody, Anti-DNase B, Anti Deoxyribonuclease B, DNA Streptococcal Antibody, DNase B, Anti Hyaluronidase

Test Codes

Mayo: ADNAS, EPIC: LAB6009, Beaker: XDNAS

Specimen Collection Criteria

Collect (preferred specimen): One Gold-top SST tube.
Also acceptable: One plain Red-top tube.

Physician Office/Draw Specimen Preparation

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells within two hours of collection. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Preparation for Courier Transport

Transport: 1.0 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 0.5 mL)

Rejection Criteria

Severely lipemic specimens.

Specimens not collected and processed as indicated.

In-Lab Processing

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells within two hours of collection. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Transport: 1.0 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 0.5 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 7 days
Refrigerated (2-8°C or 36-46°F): 28 days
Frozen (-20°C/-4°F or below): 28 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Mayo Clinic Laboratories in Rochester, MN.

Performed

Monday – Friday.
Results available in 2-5 days.

Reference Range

By report.

Test Methodology

Quantitative Nephelometry.

Interpretation

Elevated titers are consistent with a preceding infection with group A streptococci.

Clinical Utility

Elevated Dnase-B antibodies are seen in impetigo and acute glomerulonephritis. The ASO response is weak in these conditions. Detection of Dnase-B antibodies is the most sensitive test for confirming post-impetigo nephritis. Streptococcal infections will result in a positive test for anti-DNase B in 80-85% of patients. Anti-DNase-B titers rise slowly compared to ASO. Peak levels occur 4-8 weeks and persist for several months after streptococcal pharyngitis or impetigo.

Clinical Disease

Streptococcus pyogenes has long been implicated as an important course of upper respiratory tract and cutaneous disease. The principal manifestations of S. pyogenes are strep throat, scarlet fever, and skin infections (impetigo and cellulitis). Necrotizing fasciitis (the so called flesh-eating bacterial infection) has also been caused by S. pyogenes. Rapid diagnosis and treatment of S. pyogenes infections is important to prevent serious non-purulent complications associated with these infections. The most common complications include acute rheumatic fever and acute glomerulonephritis. Rheumatic fever may occur after strep throat in about 2-3% of cases. Glomerulonephritis may follow either pharyngeal or skin infections.

The most common symptoms of streptococcal pharyngitis include an abrupt onset of sore throat, malaise, headache, and a fever greater than 101°F. The throat is red with a grayish-white exudate on the tonsils.

  • Scarlet fever is caused by an exotoxin produced by a certain group of Beta-hemolytic group A streptococci. The symptoms include a skin rash on the upper chest beginning on the second day of illness. The rash fades within a week and the skin may peel.
  • Impetigo is a superficial cutaneous infection characterized by crusted lesions. It typically occurs in late summer or early fall. It is most common in tropical or semitropical climates.
  • Necrotizing fasciitis is a life-threatening, and sometimes fatal infection. Symptoms include fever, severe pain, redness, and swelling at the wound site.
  • Pyrogenic exotoxins similar to the toxic shock syndrome toxin 1 of S. aureus have been identified in some of these patients. People with chronic illness are at higher risk of acquiring invasive disease. Cuts, wounds, and chickenpox provide opportunity for bacteria to enter. Thirty percent of these patients die despite aggressive, seemingly appropriate therapy.
  • Rheumatic fever is characterized by inflammatory lesions that may involve the heart, joints, subcutaneous tissues, and central nervous system. It primarily occurs in children 6-15 years old with a recent history of group A streptococcal pharyngitis. It may be prevented by treating the patient with antibiotics within 9 days of the onset of strep throat. Onset occurs approximately 20 days after infection.
  • Acute glomerulonephritis may be a complication of either pharyngitis or cutaneous infection due to S. pyogenes. It is predominantly found in preschool and school-age children. It occurs 6-10 days after the onset of pharyngitis or 14-21 days after cutaneous infection. It is an acute inflammatory disease of the renal glomeruli. Virtually all patients have microscopic hematuria and proteinuria.

Epidemiology

Streptococcal pharyngitits occurs year-round in temperate climates, but the incidence peaks in the winter and spring months. Infections can occur in any age group but most cases occur among school-age children.

Transmission

Streptococcal infections are spread from person to person via inhalation of S. pyogenes laden respiratory droplets. Foodborne and milkborne transmission has also been described. A number of individuals, particularly school-age children, carry S. pyogenes without signs of illness. Carriers are culture positive and seronegative.

CPT Codes

86215

Contacts

Last Updated

4/10/2021

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