Treatment Of AA Amyloidosis Research Articles

Blockade of interleukin-6 as a possible therapeutic target for AA amyloidosis

IntroductionAA (secondary) amyloidosis is a severe complication of chronic inflammatory disorders. It is characterized by the systemic deposition of an abnormal protein called amyloid, affecting mainly renal function. IL-6 is a cytokine with a relevant role in this disease development. Interleukin-receptor antagonists, like Tocilizumab (TCZ), have become possible treatment choice for AA amyloidosis. In published reports, TCZ has shown good efficacy for AA amyloidosis, being associated with regression of renal amyloid deposits. MethodsRetrospective review that included patients with histological diagnosis of AA renal amyloidosis under treatment with TCZ during the years 2018–2019 in our center. We have registered clinical and demographic variables. Renal function was measured by means of CKD-EPI equation to estimate the glomerular filtration rate (FG) and protein/creatinine ratio (IPC) at 3, 6 and 12 months. We define renal response as a decrease by at least 30% of proteinuria and/or stabilization or improvement of FG. We consider that an anti-inflammatory response is a decrease of more than 50% in serum amyloid protein (PSA) and/or C-reactive protein (CRP). ResultsWe collected 3 cases of patients with histologically proven AA amyloidosis treated with TCZ (2 men; 1 woman; aged 55, 74 and 75 years). The follow-up was 13, 14 and 75 months. FG was stabilized in two patients. The third patient remained on hemodialysis during follow-up, although with excellent control of her underlying inflammatory disease. In all three cases, reduced PSA and CRP were observed. There have been no adverse events. ConclusionsThe TCZ may be an effective and safe option in treatment of AA amyloidosis with renal involvement. Our results position it as an interesting therapeutic option to consider in these cases, although prospective studies would be necessary to evaluate the global role of TCZ in AA amyloidosis.

La inhibición de la interleucina-6 como posible diana terapéutica en la amiloidosis AA

IntroductionAA (secondary) amyloidosis is a severe complication of chronic inflammatory disorders. It is characterized by the systemic deposition of an abnormal protein called amyloid, affecting mainly renal function. IL-6 is a cytokine with a relevant role in this disease development. Interleukin-receptor antagonists, like Tocilizumab (TCZ), have become possible treatment choice for AA amyloidosis. In published reports, TCZ has shown good efficacy for AA amyloidosis, being associated with regression of renal amyloid deposits. MethodsRetrospective review that included patients with histological diagnosis of AA renal amyloidosis under treatment with TCZ during the years 2018-2019 in our center. We have registered clinical and demographic variables. Renal function was measured by means of CKD-EPI equation to estimate the glomerular filtration rate (FG) and protein/creatinine ratio (IPC) at 3, 6 and 12 months. We define renal response as a decrease by at least 30% of proteinuria and/or stabilization or improvement of FG. We consider that an anti-inflammatory response is a decrease of more than 50% in serum amyloid protein (PSA) and/or C-reactive protein (CRP). ResultsWe collected 3 cases of patients with histologically proven AA amyloidosis treated with TCZ (2 men; 1 woman; aged 55, 74 and 75 years). The follow-up was 13, 14 and 75 months. FG was stabilized in two patients. The third patient remained on hemodialysis during follow-up, although with excellent control of her underlying inflammatory disease. In all three cases, reduced PSA and CRP were observed. There have been no adverse events. ConclusionsThe TCZ may be an effective and safe option in treatment of AA amyloidosis with renal involvement. Our results position it as an interesting therapeutic option to consider in these cases, although prospective studies would be necessary to evaluate the global role of TCZ in AA amyloidosis.

The analysis of secondary AA-amyloidosis current etiology and its influence on the approaches for diagnosis and treatment

To investigate an influence of the currently changed etiologic structure of AA-amyloidosis on the diagnosis and treatment tactics. In 110 patients with АА-amyloidosis followed during full disease duration (1 month 29 years) etiology, clinical manyfestations and approaches to diagnose and treatment of AA-amyloidosis were evaluated. With ELISA levels of amyloid precursor acute phase inflammation reactant SAA and neutrophil activity marker S100A12 were measured. Among the most common causes of AA-amyloidosis at the present stage, in addition to RA (40.3%), a significant place is occupied by a group of diseases with a predominantly autoinflammatory mechanism (53.73%). To confirm the autoinflammatory mechanism of the predisposing disease it is recommended to study a highly sensitive parameter serum protein S100A12. An effective marker of the risk of AA-amyloidosis progression, especially in patients with subclinical activity of inflammatory disease, is a high level of production of amyloidogenic protein-a precursor of SAA.

Causes and treatment of systemic amyloidosis

Systemic amyloidoses are rare protein deposition disorders, which are often diagnosed in an advanced stage of the disease due to non-specific symptoms. Any chronic inflammatory disease can lead to an AA-type amyloidosis. This paper summarizes the current state of the art of diagnosis and treatment of AA amyloidosis and presents data from the past 10years of our amyloidosis center. Our data represents an analysis of our cohort of patients with amyloidosis and aselective research in the PubMed database for AA amyloidosis. The underlying diseases comprise autoinflammatory syndromes, polyarthritis, and chronic inflammatory bowel and lung diseases. Renal organ involvement is the most prevalent in AA amyloidosis. It can be detected early through the evaluation of proteinuria. The treatment depends on the individual underlying disease. Patients without an associated inflammatory disease are considered to have idiopathic AA amyloidosis and empiric treatment is mandatory. Survival of this fatal disease has recently improved due to the new diagnostic tools and treatment options; however, early diagnosis plays acrucial role in the prevention of end-stage renal failure. New therapeutic strategies aim to remove existing amyloid deposits.

Lovastatin inhibits formation of AA amyloid

Amyloid A (AA) amyloidosis is a severe complication of many chronic inflammatory disorders, including the hereditary periodic fever syndromes. However, in one of these periodic fever syndromes, the hyper IgD and periodic fever syndrome, amyloidosis is rare despite vigorous, recurring inflammation. This hereditary syndrome is caused by mutations in the gene coding for mevalonate kinase, an enzyme of the isoprenoid pathway. In this study, we used a cell culture system with human monocytes to show that inhibition of the isoprenoid pathway inhibits amyloidogenesis. Inhibition of the isoprenoid pathway by lovastatin resulted in a dose-dependent reduction of amyloid formed [53% at 10 microM (P=0.01)] compared with mononuclear cells that are exposed only to serum AA. The inhibitory effects of lovastatin are reversible by addition of farnesol but not geranylgeraniol. Farnesyl transferase inhibition also inhibited amyloidogenesis. These results implicate that the isoprenoid metabolism could be a potential target for prevention and treatment of AA amyloidosis.