title: Lysozyme amyloidosis: report of 4 cases and a review of the literature.
abstract: Autosomal dominant hereditary amyloidosis represents not 1 disease but a group of diseases, each the result of mutations in a specific protein. The most common form is transthyretin amyloidosis, which has been recognized clinically for over 50 years as a familial polyneuropathy. Nonneuropathic amyloidoses (Ostertag type amyloidosis) include those due to abnormalities in lysozyme, fibrinogen Aalpha-chain, and apolipoprotein A-I and A-II. The role of lysozyme in amyloid-related human disorders was first described in 1993; to date, there have been only 9 publications describing this disorder, which is a nonneuropathic form of hereditary amyloidosis. Reported cases have involved 7 unrelated families. We describe here our own experience with 4 families suffering from lysozyme amyloidosis: the first had prominent renal manifestations with sicca syndrome, the second and third had prominent gastrointestinal symptoms, and the fourth had a dramatic bleeding event due to rupture of abdominal lymph nodes. To our knowledge, this last symptom has not been reported previously, but is reminiscent of the hepatic hemorrhage seen in a previously reported case of a patient with lysozyme amyloidosis. To characterize the manifestations of this disorder, we performed an exhaustive literature review.Although hereditary amyloidosis is thought to be a rare disease, it is probably not as rare as we think and may well be underdiagnosed. Moreover, some cases of lysozyme amyloidosis are probably confused with acquired monoclonal immunoglobulin light-chain (AL) amyloidosis, formerly known as primary amyloidosis, which is the most frequent type of amyloidosis. Because treatment for each type of amyloidosis is different, and because therapy directed at 1 type may worsen symptoms of the other types, it is important to determine precisely the nature of the amyloid protein. Thus, hereditary lysozyme amyloidosis should be considered in all patients with systemic amyloidosis, particularly in patients who present with renal, gastrointestinal, or bleeding complications without evidence of AL or AA (secondary) amyloidoses.
authors.affiliation: From Service de médecine interne (BG), hôpital Nord, Assistance Publique-Hôpitaux de Marseille (AP-HM), Marseille; Laboratoire de biochimie et génétique moléculaire (SV, GG), hôpital Cochin, Assistance Publique-Hôpitaux de Paris (AP-HP) et INSERM U567, Paris; Service de médecine interne (JS, P-JW), hôpital de la Timone, AP-HM, Marseille; Service de médecine interne (PC, AT), hôpital de la Pitié Salpêtrière, Paris; Service de médecine interne (GG), hôpital Tenon, AP-HP, Paris, France.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Granel
authors.forename: Sophie
authors.initials: S
authors.lastname: Valleix
authors.forename: Jacques
authors.initials: J
authors.lastname: Serratrice
authors.forename: Patrick
authors.initials: P
authors.lastname: Chérin
authors.forename: Antonio
authors.initials: A
authors.lastname: Texeira
authors.forename: Patrick
authors.initials: P
authors.lastname: Disdier
authors.forename: Pierre-Jean
authors.initials: PJ
authors.lastname: Weiller
authors.forename: Gilles
authors.initials: G
authors.lastname: Grateau
mesh_terms: D000328:Adult; D000368:Aged; D000686:Amyloidosis / Q000150:complications* / Q000201:enzymology / Q000503:physiopathology*; D005260:Female; D005767:Gastrointestinal Diseases / Q000209:etiology; D006470:Hemorrhage; D006801:Humans; D007674:Kidney Diseases / Q000209:etiology; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009113:Muramidase / Q000378:metabolism*; D012421:Rupture
chemical_list: D009113:Muramidase