Microscopic colitis in Uppsala health region, a population-based prospective study 2005-2009.

OBJECTIVE: The aim of this study is to report on the incidence of microscopic colitis (MC), any possible relation with inflammatory bowel disease (IBD), concomitant drug consumption, related diseases and the clinical course of the diseases. METHODS: Both new cases of IBD and MC were registered at the same time in the same geographical area. The study started in the county of Uppsala 2005-2006, and other parts of the surrounding health region were included 2007-2009. Established morphological criteria were used, i.e. a layer of subepithelial collagen band ≥ 10 µm in collagenous colitis (CC) with concomitant inflammation and at least 20 lymphocytes per 100 epithelial cells in lymphocytic colitis (LC). RESULTS: The authors found 272 new cases of MC, 154 with CC and 118 with LC. The mean age-adjusted incidence was 7.0/1,000,000 for CC and 4.8/100,000 for LC. The clinical course was dominated by single episodes with diarrhea or intermittent symptoms, but 14% suffered from chronic diarrhea. In 10% of the cases, diagnosis was made in individuals without chronic watery diarrhea. Although not systematically tested, concomitant celiac disease was found in approximately 5% of the patients. CONCLUSIONS: The incidence of MC in Uppsala health region is similar to other studied areas. The majority of patients had a self-limiting or easily treated condition, but 14% need a more or less continuous medication. Ten percent of the patients demonstrate other symptoms than chronic watery diarrhea. The possibility of concomitant celiac disease should be considered in new cases of MC.

Tissue-based diagnosis of systemic amyloidosis: Experience of the informal diagnostic center at Uppsala University Hospital.

Diagnosis of systemic amyloidosis is a clinical challenge and usually relies on a tissue biopsy. We have developed diagnostic methods based on the presence of amyloid deposits in abdominal subcutaneous fat tissue. This tissue is also used to determine the biochemical type of amyloidosis, performed by western blot and immunohistochemical analyses with the aid of in-house developed rabbit antisera and mouse monoclonal antibodies. Mass spectrometric methods are under development for selected cases. The diagnostic outcome for 2018-2020 was studied. During this period, we obtained 1,562 biopsies, of which 1,397 were unfixed subcutaneous fat tissue with varying degrees of suspicion of systemic amyloidosis. Of these, 440 contained amyloid deposits. The biochemical nature of the amyloid was determined by western blot analysis in 319 specimens and by immunohistochemistry in further 51 cases.

Cardiac microcalcifications in transthyretin (ATTR) amyloidosis.

BACKGROUND: Bone tracers bind to amyloid-containing heart of most patients with ATTR amyloidosis. Amyloid deposits outside the heart are often scarce and bone scintigraphy is increasingly often used to diagnose cardiac involvement. However, the nature of the binding of bone tracers to the heart is not clear. OBJECTIVE: To identify possible calcium deposits in hearts with amyloid, explaining bone tracer binding. METHODS AND RESULTS: Formalin-fixed and paraffin embedded cardiac specimens from three patients with ATTR and one with AL amyloidosis, all with cardiac deposits, were studied. The specimens covered large parts of the heart. Sections were stained immunohistochemically for ATTR deposits and according to von Kóssa for calcifications. The study identified in all hearts, but particularly in the ATTR materials, focal, tight swarms of tiny calcifications. These were sometimes associated with amyloid but found as frequent in areas without such deposits. Autoradiography with [99mTc]Tc labelled 3,3-disphos-phono-1,2-propanodicarboxylic acid (DPD) revealed labelling in von Kóssa positive areas. Electron microscopically the particles were not amorphous but had a complex structured appearance and were often surrounded by a membrane, indicating a cellular origin. Labelling with antibodies against ubiquitin and P62 pointed to result from autophagy. CONCLUSIONS: Our study indicates that binding of skeletal probes to amyloid-containing hearts depends on an irregular presence of clouds of very tiny calcifications, which seem not to be directly associated with amyloid fibrils. Therefore, [99mTc]Tc-DPD bone scans can be considered surrogate markers of ATTR amyloid but have to be used carefully to estimate amyloid amount or disease progression.