Scarpellini P, Delfanti F, Finazzi R, Vago L, Dell'Antonio G, Lazzarin A; International Conference on AIDS.
Int Conf AIDS. 1994 Aug 7-12; 10: 161 (abstract no. PB0659).
IRCCS Ospedale S. Raffaele, Milan, Italy.
OBJECTIVE: to compare a new assay based on the amplification of Mycobacterium tuberculosis (Mt) DNA by PCR with hystological findings and standard microbiologic procedures in the diagnosis of tubercular adenitis (TA) in HIV infected patients. PATIENTS, MATERIALS AND METHODS: 14 lymphnode tissues (4 biopsies and 10 autoptical specimens) collected from patients with TA were processed by PCR. Caseation necrosis and/or granulomas were seen in all specimens. Strains for acid fast bacilli and cultures on conventional media were positive in 57% of the eleven specimens evaluated. Additional 14 tissue samples were processed as negative controls; 4 were lymphnode biopsies (2 HIV-correlated adenitis, 1 Hodgkin's disease, 1 Mycobacterium avium adenitis). Specimens were autoptical and collected from other sites, hystologically not involved by tubercular process, in 10 patients with TA. A nested PCR assay was developed for the final amplification of a 123-bp fragment of the Mt insertion element IS6110. Two methods of sample preparation were used: the chaotrope-silica method and the boiling method in the presence of Chelex-100. The amplified products were visualized on 1.8% agarose gel containing ethidium bromide. The specificity of the band was confirmed by hybridization assay by means of an internal P32 labelled probe. RESULTS: One fg of Mt DNA, which is equivalent to about 1 copy of the Mt chromosome, was amplified reproducibly giving a clearly detectable band in agarose gel. All but one of the specimens with hystological diagnosis of TA gave positive results when assessed by the PCR. Even though this is to be classified as a false negative it should be noticed that a therapy with antitubercular agents was started before the collection of the specimen. All the specimens with no hystological evidence of TA gave negative results when assessed by the PCR. In brief, PCR can be considered a valid diagnostic technique in formalin fixed paraffine embebbed tissues. This technique has the advantages in respect to culture of the possibility to discriminate between tubercular and non-tubercular mycobacteriosis, and of being more rapid.
Publication Types:
Keywords:
- Acquired Immunodeficiency Syndrome
- DNA Primers
- DNA Transposable Elements
- Formaldehyde
- Granuloma
- Humans
- Mycobacterium Infections
- Mycobacterium avium
- Mycobacterium tuberculosis
- Paraffin Embedding
- Polymerase Chain Reaction
- Sensitivity and Specificity
- genetics
Other ID:
UI: 102210096
From Meeting Abstracts