Key Information
Background
Ankylosing spondylitis (AS) is a type of chronic inflammation that is most prevalent in young adults and is characterized by an inflammatory enthesiopathy that gradually develops toward ossification and ankylosis. If inflammation is left unchecked, it can potentially lead to complications such as secondary amyloidosis, also known as AA amyloidosis, involving the deposition of amyloid serum A protein. Our case presents with a thyroid localization of AA amyloidosis which is secondary to this AS. Such a case has been described in only four cases in the literature. Cardiac localization of AA amyloidosis has been exceptionally described in the literature.
Case presentation
We report the case of a young patient with severe AS complicated by secondary amyloidosis with thyroid, cardiac, and probably renal localization. He was treated with anti-TNF therapy, and his condition improved significantly.
Conclusions
Our case presents several localizations of AA amyloidosis secondary to this AS. Although cardiac involvement is rare in secondary AA amyloidosis, it should always be screened for, even in a cardiacly asymptomatic patient.
Background
Secondary amyloidosis (AA) is an important complication of chronic inflammatory diseases. Rheumatologic diseases such as rheumatoid arthritis (RA) and ankylosing spondylitis (AS) are known to be associated with the development of AA amyloidosis. Although AS affects the spine and sacroiliac joints as well as peripheral joints, other extra-articular manifestations are possible and include acute anterior uveitis, aortic insufficiency, apical pulmonary fibrosis, and systemic amyloidosis. AA is a systemic disease characterized by amyloid deposition in many organs. The kidney is the most affected organ, damage to the thyroid gland is possible, but cardiac involvement remains rare during secondary amyloidosis. The present case illustrates a unique presentation of multisystem secondary amyloidosis.
Case presentation
A 33-year-old male patient, on dialysis since the age of 26 for kidney damage of undocumented origin, referred to an internal medicine consultation for the etiological assessment of a large amyloid goiter (Fig. 1external link, opens in a new tab) evolving for 3 years with a normal thyroid balance initially. During the interrogation, the patient reported since the age of 16 years inflammatory low back pain associated with buttock pain, heel pain, and enthesopathy, which prompted the patient to self-medicate with nonsteroidal anti-inflammatory drugs if necessary. On clinical examination, the patient presented with kypho-scoliosis, stiffness of the cervical, dorsal, and lumbar spine (Fig. 2external link, opens in a new tab) as well as pain on passive and active mobilization of both hips. The rest of the somatic examination was unremarkable, including no cardiovascular symptoms.