Background. Systemic amyloidosis is a potentially fatal condition, unless diagnosed and treated before development of irreversible organ damage. Demonstration of amyloid deposits within tissue biopsies is only definitive diagnostic method, which makes appropriate selection of biopsy site essential. Herein, we evaluated efficacy of minimally invasive minor salivary gland biopsy (MSGB) for the diagnosis of amyloidosis. Methods. We analyzed 37 biopsies taken from 35 patients. Suggestive findings for amyloidosis were significant proteinuria, renal impairment, refractory diarrhea, neuropathy, and restrictive cardiomyopathy. Minor salivary gland was the initial biopsy site in all subjects. When MSGB was negative but there was a high suspicion for amyloidosis, a kidney, duodenum, or rectal biopsy was performed for further investigation. Results. Mean age of patients was 45.4 and 21 were female. In 11 patients amyloidosis was diagnosed with MSGB. In overall 18 patients were diagnosed with amyloidosis. Sixteen of them were identified as being of AA type and two were AL type amyloidosis. The sensitivity of minimally invasive MSGB is 61.1% for diagnosing amyloidosis in this study. Conclusion. MSGB is a safe and simple method for the diagnosis of amyloidosis which can be performed in an outpatient setting. We suggest extensive use of this minimally invasive method. 1. Introduction Amyloidosis is a potentially fatal condition characterized by extracellular deposition of nonbranching protein fibrils in organs [1]. This devastating condition is mainly caused by plasma cell disorders and numerous inflammatory diseases including autoimmune and chronic infectious diseases [2, 3]. Demonstration of amyloid deposits in biopsy specimens is the only way of establishing the diagnosis of amyloidosis [4, 5]. Therefore, appropriate selection of biopsy site is essential. The sensitivity and specificity of histopathology varies greatly according to where the tissue biopsy is obtained [5, 6]. Sensitivity of biopsy samples from visceral organs is higher; however, it requires more invasive procedures with bearing higher risk of complications, such as bleeding, hematoma, and perforation. Abdominal fat pad, gingiva, and rectum are the most common initial biopsy sites because of their ease of accessibility, low complication rate, and lower costs [5]. However, diagnostic yield of these biopsies is somewhat lower compared to visceral organ biopsies. Minor salivary glands have parenchymal and secretory components with considerable blood supply. Therefore, labial salivary glands are a good
References
[1]
G. Palladini and G. Merlini, “Systemic amyloidoses: what an internist should know,” European Journal of Internal Medicine, vol. 24, no. 8, pp. 729–739, 2013.
[2]
B. P. Hazenberg, “Amyloidosis: a clinical overview,” Rheumatic Disease Clinics of North America, vol. 39, no. 2, pp. 323–345, 2013.
[3]
M. F. Khan and R. H. Falk, “Amyloidosis,” Postgraduate Medical Journal, vol. 77, no. 913, pp. 686–693, 2001.
[4]
P. Mollee, P. Renaut, D. Gottlieb, and H. Goodman, “How to diagnose amyloidosis,” Internal Medicine Journal, 2013.
[5]
E. Hachulla and G. Grateau, “Diagnostic tools for amyloidosis,” Joint Bone Spine, vol. 69, no. 6, pp. 538–545, 2002.
[6]
B. P. Hazenberg, J. Bijzet, P. C. Limburg, et al., “Diagnostic performance of amyloid A protein quantification in fat tissue of patients with clinical AA amyloidosis,” Amyloid, vol. 14, no. 2, pp. 133–140, 2007.
[7]
W. A. Delgado and A. Mosqueda, “A highly sensitive method for diagnosis of secondary amyloidosis by labial salivary gland biopsy,” Journal of Oral Pathology and Medicine, vol. 18, no. 5, pp. 310–314, 1989.
[8]
R. Caporali, E. Bonacci, O. Epis, F. Bobbio-Pallavicini, P. Morbini, and C. Montecucco, “Safety and usefulness of minor salivary gland biopsy: retrospective analysis of 502 procedures performed at a single center,” Arthritis and Rheumatism, vol. 59, no. 5, pp. 714–720, 2008.
[9]
E. Hachulla, A. Janin, R. M. Flipo et al., “Labial salivary gland biopsy is a reliable test for the diagnosis of primary and secondary amyloidosis: a prospective clinical and immunohistologic study in 59 patients,” Arthritis and Rheumatism, vol. 36, no. 5, pp. 691–697, 1993.
[10]
D. Real de Asúa, R. Costa, M. M. Contreras, á. Gutiérrez, M. T. Filigghedu, and M. Armas, “Clinical characteristics of the patients with systemic amyloidosis in 2000–2010,” Revista Clínica Espa？ola, vol. 213, no. 4, pp. 186–193, 2013.
[11]
A. Foli, G. Palladini, R. Caporali et al., “The role of minor salivary gland biopsy in the diagnosis of systemic amyloidosis: results of a prospective study in 62 patients,” Amyloid, vol. 18, supplement 1, pp. 80–82, 2011.
[12]
J. A. Friedman, E. B. Miller, and M. Huszar, “A simple technique for minor salivary gland biopsy appropriate for use by rheumatologists in an outpatient setting,” Clinical Rheumatology, vol. 21, no. 4, pp. 349–350, 2002.
[13]
M. M. Picken, “Modern approaches to the treatment of amyloidosis: the critical importance of early detection in surgical pathology,” Advances in Anatomic Pathology, vol. 20, no. 6, pp. 424–439, 2013.
[14]
J. D. Gillmore, L. B. Lovat, M. R. Persey, M. B. Pepys, and P. N. Hawkins, “Amyloid load and clinical outcome in AA amyloidosis in relation to circulating concentration of serum amyloid A protein,” The Lancet, vol. 358, no. 9275, pp. 24–29, 2001.
[15]
R. A. Kyle and M. A. Gertz, “Primary systemic amyloidosis: clinical and laboratory features in 474 cases,” Seminars in Hematology, vol. 32, no. 1, pp. 45–59, 1995.
[16]
S.-J. Sacsaquispe, E.-A. Antúnez-de Mayolo, R. Vicetti, and W.-A. Delgado, “Detection of AA-type amyloid protein in labial salivary glands,” Medicina Oral, Patologia Oral y Cirugia Bucal, vol. 16, no. 2, pp. e149–e152, 2011.
[17]
N. Sarkar and V. K. Dubey, “Exploring critical determinants of protein amyloidogenesis: a review,” Journal of Peptide Science, vol. 19, no. 9, pp. 529–536, 2013.
