Molecular, Histologic and Clinical Features of Persistent Intestinal Spirochetosis
Kirsten Threlkeld, Thomas Trainer, Christine Adamson, Mark Evans, Rebecca Wilcox. University of Vermont, Burlington, VT
Background: Although human intestinal spirochetosis(IS) is a well-documented entity, its clinical significance remains controversial. Brachyspira aalborgi and pilosicoli are the species most commonly associated with human IS. We performed a retrospective analysis of colorectal biopsies in patients found to have persistent IS with the goal of highlighting molecular,histologic and clinical features.
Design: We identified all pts diagnosed with IS in our institution over the last 11yrs. Of these pts, those with at least one additional lower GI specimen in our database were defined as study patients. Retrospective exam of study slides(documenting IS,associated histology,recognition of IS in SP reports) and clinical data(reason to biopsy,symptoms,additional diagnoses,immune status) was performed. Primary molecular detection was achieved by amplifying species-specific portion of 16S ribosomal RNA. Non-amplfied cases were tested for viable DNA using β-globin.
Results: 29 pts (70 biopsies) had persistent(2mo-14yr) IS(66% male:35-91yrs;mean57.9yrs). In 32/70 biopsies(46%), IS was identified by H&E on retrospective review only(not documented in SP report). 8/29 pts had a history of immunosuppression(treated IBD, carcinoma,lymphoma). Reason to biopsy, associated histology and causative species are summarized in Table 1. The 9 samples(17%) positive for IS on H&E but not amplified by PCR all had additional biopsies that speciated as B. aalborgi. 27 additional pts had “non-persistent” IS (IS at one point in time with negative prior or subsequent colorectal biopsies). These cases all typed as B. aalborgi with an exception of one B. pilosicoli. The pt with B. pilosicoli was a homosexual male with diarrhea and active colitis.
|Reason to Biopsy||Histology∗||Species|
|Diarrhea;R/O Microscopic Colitis||7%||Polyp: HP||33%||Non-Amplified||17%|
|Heme + Stool||6%||Polyp: TA||9%|
|IBD Surveillance||3%||Polyp: SSA||4%|
|Hx of Colitis||3%||Polyp: TVA||1%|
|Other||3%||Chronic Active Colitis||1%|