Sorted By Test Name - Mayo Medical Laboratories

ACT
8221
APT
9058
and isolation of infected persons is important. Detection of acid-fast bacilli in sputum specimens allows
rapid identification of individuals who are likely to be infected while definitive diagnosis and treatment
are pursued.
Useful For: Detection of acid-fast bacilli in clinical specimens
Interpretation: Patients whose sputum specimens are identified as acid-fast positive should be
considered potentially infected with Mycobacterium tuberculosis, pending definitive diagnosis by
molecular methods and/or mycobacterial culture.
Reference Values:
Negative (reported as positive or negative)
Clinical References: Pfyffer GE, Brown-Elliot BA, Wallace RJ: General characteristics, isolation,
and staining procedures. In Manual of Clinical Microbiology. 8th edition. Washington, DC, ASM Press,
2003, pp 532-559
Actinomyces Culture
Clinical Information: Anaerobic Actinomyces are non sporeforming, thin branching, gram-positive
bacilli which are part of the normal flora of the human oral cavity and which may also colonize the
gastrointestinal and female genital tracts. Their presence is important in preserving the usual bacterial
populations of the mouth and in preventing infection with pathogenic bacteria. Actinomyces are generally
of low pathogenicity but may be an important factor in the development of periodontal disease and may
cause soft tissue infections in colonized areas of the body following trauma (surgical or otherwise). The
typical lesion consists of an outer zone of granulation around central purulent loculations containing
masses of tangled organisms ("sulfur granule"). Chronic burrowing sinus tracts develop. Typical
actinomycotic infections occur around the head and neck, in the lung and chest wall, and in the peritoneal
cavity and abdominal wall. Actinomycosis of the female genital tract occurs in association with use of
intrauterine contraceptive devices. Purulent collections containing "sulfur granules" may drain from some
sinus tracts opening to the skin.
Useful For: Diagnosing anaerobic Actinomyces involved in infections
Interpretation: Isolation of anaerobic Actinomyces in significant numbers from well collected
specimens including blood, other normally sterile body fluids, or closed collections of purulent fluid
indicates infection with that (those) organism(s).
Reference Values:
Not applicable
Clinical References: 1. Finegold SM, George WL: Anaerobic Infections in Humans. San Diego,
CA, Academic Press, 1989 2. Summanen P, Baron EJ, Citron D, et al: Wadsworth Anaerobic
Bacteriology Manual, 5th edition. Star Publishing Co. 1993
Activated Partial Thromboplastin Time (APTT), Plasma
Clinical Information: The activated partial thromboplastin time (APTT) test reflects the activities of
most of the coagulation factors, including factor XII and other "contact factors" (prekallikrein [PK] and
high molecular weight kininogen [HMWK]) and factors XI, IX, and VIII in the intrinsic procoagulant
pathway, as well as coagulation factors in the common procoagulant pathway that include factors X, V, II
and fibrinogen (factor I). The APTT also depends on phospholipid (a partial thromboplastin) and ionic
calcium, as well as an activator of the contact factors (eg, silica), but reflects neither the extrinsic
procoagulant pathway that includes factor VII and tissue factor, nor the activity of factor XIII (fibrin
stabilizing factor). The APTT is variably sensitive to the presence of specific and nonspecific inhibitors of
the intrinsic and common coagulation pathways, including lupus anticoagulants or antiphospholipid
antibodies. Lupus anticoagulants may interfere with in vitro phospholipid-dependent coagulation tests,
such as the APTT, and prolong the clotting time. Lupus anticoagulants are antibodies directed towards
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