Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report the first description of sevelamer crystals (Renagel and Renvela, Genzyme; phosphate-lowering agents) in the gastrointestinal tract. We prospectively collected cases with novel, histologically identical crystals from 4 major academic centers over a 1-year period and studied pertinent clinicopathologic features. Sevelamer usage in the setting of chronic kidney disease was demonstrated in all cases (n=15 total cases, 7 patients). Sites of involvement included the esophagus (n=2), small bowel (n=2), and colon (n=11). The background mucosa was normal in only 1 case. Notable mucosal abnormality included chronic mucosal damage (n=5), acute inflammation (n=4), inflammatory polyp (n=2), extensive ulceration (n=2), ischemia (n=1), and necrosis (n=1). In general, sevelamer crystals displayed broad, curved, and irregularly spaced "fish scales" with a variably eosinophilic to rusty brown color on hematoxylin and eosin (H&E) staining and violet color on periodic acid-Schiff-alcian special staining with diastase (PAS/D). To validate these findings, sevelamer tablets (Renvela) were crushed and submitted for histologic processing; the findings were identical to those in the patient specimens. The possibility of Kayexalate (sodium polystyrene sulfonate) and cholestyramine had been raised in error. However, Kayexalate has narrow, rectangular "fish scales" and is violet on H&E and magenta on PAS/D; cholestyramine lacks internal "fish scales," is bright orange on H&E, variably gray or hot pink on PAS/D, and is unassociated with mucosal injury. Further study is required to determine whether sevelamer plays a causal role in these injuries; however, its crystal is an important mimic of both Kayexalate and choleystyramine. As the history of sevelamer administration was not documented in any pathology requisition, awareness of sevelamer's characteristic morphology is crucial to avoid the diagnostic pitfalls of its mimics.
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PMID:Sevelamer crystals in the gastrointestinal tract (GIT): a new entity associated with mucosal injury. 2406 14

End stage renal disease (ESRD) population account for 1.9 per patient year of hospital admissions annually. ESRD population are at increased risk of bleeding secondary to use of anticoagulation during hemodialysis and uremia induced platelet dysfunction. Gastrointestinal bleeding accounts for 3-7% of all deaths in ESRD population. Lower gastrointestinal bleeding refers to blood loss from a site in the gastrointestinal tract distal to the ligament of Treitz. It is usually suspected when a patient complains of hematochezia. It is different from patients presenting with hematemesis that suggests bleeding from upper gastrointestinal tract. Common causes of lower gastrointestinal bleed include diverticulosis, ischemia, hemorrhoids, neoplasia, angiodysplasia, and inflammatory bowel disease. ESRD patients are known to retain phosphate alone or in combination with calcium which has been associated with high mortality. Sevelamer is a phosphate binder used widely in ESRD population. The known side effects of sevelamer include metabolic acidosis, vomiting, nausea, diarrhea, dyspepsia, abdominal pain, constipation, flatulence, fecal impaction, and skin rash. We are reporting a unique case of a 56-year-old female with end stage renal disease on sevelamer hydrochloride who presented with gastrointestinal bleeding and underwent a right hemicolectomy found to have sevelamer-induced mucosal ulceration and crystal deposition in the colonic mucosa. This case report highlights the fact that, with widespread use of this medication in the patients with chronic kidney diseases, physicians should be aware of this underrecognized entity in the differential diagnosis of gastrointestinal bleed in ESRD patients.
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PMID:Colonic Mucosal Ulceration and Gastrointestinal Bleeding Associated with Sevelamer Crystal Deposition in a Patient with End Stage Renal Disease. 2968 71

Sevelamer is an important drug used to lower serum phosphate levels in advanced kidney disease and in patients on dialysis. This drug is generally well tolerated but some patients report mild gastrointestinal distress as a side effect. Although regulatory agencies, such as Food and Drug Administration, list bowel ischemia and necrosis as potential and rare side effects, there are few case reports describing these adverse effects. We present a 35-year-old HIV patient with end-stage renal disease on hemodialysis who developed colonic hemorrhage and perforation. Imaging showed ischemic gangrene of bowel wall. Histopathology was consistent with transmural ischemic necrosis with deposition of fibrin thrombi and sevelamer crystals.
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PMID:Ischemic Colitis in Association with Sevelamer Crystals. 3114 66