Clinical features and outcomes of systemic amyloidosis with gastrointestinal involvement: a single-center experience

BACKGROUND/AIMS: The gastrointestinal (GI) tract often becomes involved in patients with systemic amyloidosis. As few GI amyloidosis data have been reported, we describe the clinical features and outcomes of patients with pathologically proven GI amyloidosis. METHODS: We identified 155 patients diagnosed with systemic amyloidosis between April 1995 and April 2013. Twenty-four patients (15.5%) were diagnosed with GI amyloidosis using associated symptoms, and the diagnoses were confirmed by direct biopsy. RESULTS: Among the 24 patients, 20 (83.3%) had amyloidosis light chain (AL), three (12.5%) had amyloid A, and one (4.2%) had transthyretin-related type amyloidosis. Their median age was 57 years (range, 37 to 72), and 10 patients were female (41.7%). The most common symptoms of GI amyloidosis were diarrhea (11 patients, 45.8%), followed by anorexia (nine patients, 37.5%), weight loss, and nausea and/or vomiting (seven patients, 29.2%). The histologically confirmed GI tract site in AL amyloidosis was the stomach in 11 patients (55.0%), the colon in nine (45.0%), the rectum in seven (35.0%), and the small bowel in one (5.0%). Patients with GI involvement had a greater frequency of organ involvement (p = 0.014). Median overall survival (OS) in patients with GI involvement was shorter (7.95 months; range, 0.3 to 40.54) than in those without GI involvement (15.84 months; range, 0.0 to 114.53; p = 0.069) in a univariate analysis. A multivariate analysis of prognostic factors for AL amyloidosis revealed that GI involvement was not a significant predictor of OS (p = 0.447). CONCLUSIONS: The prognosis of patients with AL amyloidosis and GI involvement was poorer than those without GI involvement, and they presented with more organ involvement and more advanced disease than those without organ involvement.

Characterization of plasma cell subsets in thyroid disease

La glándula tiroides puede presentar patologías que desde el punto de vista histológico muestran diferentes grados de infiltración linfocitaria y plasmocitaria. Con el fin de identificar los subtipos de células plasmáticas en algunas patologías tiroideas nosotros hemos realizado un estudio inmunohistoquímico sobre la presencia de cadenas pesadas (IgG, IgA, IgM) y livianas (K y L) que se pueden encontrar en el citoplasma de las células plasmáticas. En las tiroiditis de Hashimoto estudiadas se encontró un predominio de células plasmáticas conteniendo IgG y kappa. El estroma linoplasmocitario que a veces acompaña al carcinoma papilar de tiroides también mostró una mayor frecuencia de células plasmáticas con IgG, aunque lambda fue la cadena liviana predominante en este caso. Por otro lado, las tiroiditis de Riedel mostraron un mayor predominio de IgA y lambda. Los 6 casos de fibrosis retroperitoneal, enfermedad a veces asociada con tiroiditis de Riedel, mostraron en conjunto una distribución de subtipos de células plasmáticas similar a la observada en las tiroiditis de Riedel aunque la frecuencia de células con IgA fue menos marcada. Estos resultados sugieren que la desigual distribución de inmunoglobulinas citoplasmáticas en estas entidades estudiadas puede estar relacionada con la presencia de diferentes antígenos involucrados en el proceso patogénico que trae aparejado el infiltrado linfoplasmocitario