Post by LymeEnigma on Dec 27, 2008 14:55:53 GMT -8
Aims: In 2003, pseudorosettes were described as highly suspicious of infection by Borrelia burgdorferi
sensu lato in the appropriate clinical context. Nevertheless, such a pattern has been described in the
literature in other non-infectious conditions. On the other hand, granuloma annulare (GA) has been
recently closely associated with infection by Borrelia. We investigated how frequently pseudorosettes
can be detected in common GA cases confirmed for Borrelia by PCR.
Methods and results: We studied 13 biopsies of non-interstitial GA and 2 biopsies of interstitial GA
from patients without clinical suspicion of borrelial infection. We also performed immunohistochemical
studies in all the biopsies, using the CD-68 antibody. Molecular studies with PCR were performed with
β-globin PCR (human DNA). Borrelial DNA was confirmed by amplifying the OspA gene and intergenic
rrf-rrl region. We found histiocytic pseudorosettes in 13 biopsies (86.66%). Human DNA was successfully
amplified from 8 of 13 paraffin-embedded skin samples. From these we amplified borrelial DNA in
5 of 8 samples. Out of the 8 cases in which human DNA was amplified, a correlation between
pseudorosettes and the molecular tests (Borrelia DNA) was confirmed in 5 instances.
Conclusions: a) Pseudorosettes are not an unusual finding in common granuloma annulare; b) Borrelia
is present in (most) cases of granuloma annulare; and c) Pseudorosettes seem to be a good morphological
sign predictive of infection with Borrelia in granuloma annulare.
Full article (free): www1.mf.uni-lj.si/acta-apa/acta-apa-08-4/4.pdf
sensu lato in the appropriate clinical context. Nevertheless, such a pattern has been described in the
literature in other non-infectious conditions. On the other hand, granuloma annulare (GA) has been
recently closely associated with infection by Borrelia. We investigated how frequently pseudorosettes
can be detected in common GA cases confirmed for Borrelia by PCR.
Methods and results: We studied 13 biopsies of non-interstitial GA and 2 biopsies of interstitial GA
from patients without clinical suspicion of borrelial infection. We also performed immunohistochemical
studies in all the biopsies, using the CD-68 antibody. Molecular studies with PCR were performed with
β-globin PCR (human DNA). Borrelial DNA was confirmed by amplifying the OspA gene and intergenic
rrf-rrl region. We found histiocytic pseudorosettes in 13 biopsies (86.66%). Human DNA was successfully
amplified from 8 of 13 paraffin-embedded skin samples. From these we amplified borrelial DNA in
5 of 8 samples. Out of the 8 cases in which human DNA was amplified, a correlation between
pseudorosettes and the molecular tests (Borrelia DNA) was confirmed in 5 instances.
Conclusions: a) Pseudorosettes are not an unusual finding in common granuloma annulare; b) Borrelia
is present in (most) cases of granuloma annulare; and c) Pseudorosettes seem to be a good morphological
sign predictive of infection with Borrelia in granuloma annulare.
Full article (free): www1.mf.uni-lj.si/acta-apa/acta-apa-08-4/4.pdf