French practical guidelines for the diagnosis and management of AA amyloidosis

AA amyloidosis is secondary to the deposit of excess insoluble Serum Amyloid A (SAA) protein fibrils. AA amyloidosis complicates chronic inflammatory diseases, especially chronic inflammatory rheumatisms such as rheumatoid arthritis and spondyloarthritis; chronic infections such as tuberculosis, bronchectasia, chronic inflammatory bowel diseases such as Crohn's disease; and auto-inflammatory diseases including familial Mediterranean fever. This work consists of the French guidelines for the diagnosis workup and treatment of AA amyloidosis. We estimate in France between 500 and 700 cases in the whole French population, affecting both men and women. The most frequent organ impaired is kidney which usually manifests by oedemas of the lower extremities, proteinuria, and/or renal failure. Patients are usually tired and can display digestive features anf thyroid goiter. The diagnosis of AA amyloidosis is based on detection of amyloid deposits on a biopsy using Congo Red staining with a characteristic green birefringence in polarized light. Immunohistochemical analysis with an antibody directed against Serum Amyloid A protein is essential to confirm the diagnosis of AA amyloidosis. Peripheral inflammatory biomarkers can be measured such as C Reactive protein and SAA. We propose an algorithm to guide the etiological diagnosis of AA amyloidosis. The treatement relies on the etiologic treatment of the undelying chronic inflammatory disease to decrease and/or normalize Serum Amyloid A protein concentration in order to stabilize amyloidosis. In case of renal failure, dialysis or even a kidney transplant can be porposed. Nowadays, there is currently no specific treatment for AA amyloidosis deposits which constitutes a therapeutic challenge for the future.

Autoimmune polyendocrine syndrome type 1 in north-western France: AIRE gene mutation specificities and severe forms needing immunosuppressive therapies

BACKGROUND

Autoimmune polyendocrine syndrome type 1 (APS1) has been poorly evaluated in France. We focused on the north-western part of the country to describe clinical phenotypes, especially severe forms of the disease, and AIRE gene mutations.

METHODS

Clinical and immunological data were collected, and pathological mutations were identified by DNA sequencing.

RESULTS

Nineteen patients were identified with APS1. Clinical manifestations varied greatly, showing 1-10 components. Mucocutaneous candidiasis, adrenal failure, hypoparathyroidism, alopecia and other severe infections were the most frequent components. Four patients had severe forms, needing immunosuppressive therapy: 2 for hepatitis; 1 for severe malabsorption, and 1 for a T cell large granular lymphocytic leukemia. These therapies were very effective but caused general discomfort. One patient died of septicemia. Four different AIRE gene mutations were identified, and a 13-bp deletion in exon 8 (c.967-979del13) was the most prevalent. There was at least one allele correlating with this mutation and alopecia occurrence (p = 0.003). No novel mutation was detected.

CONCLUSION

APS1 appears to be rare in north-western France. We identified 4 cases with a severe form needing immunosuppressive therapy. The AIRE gene mutations are more like those found in north-western Europe than those found in Finland.

Predominant Th1 and cytotoxic phenotype in biopsies from renal transplant recipients with transplant glomerulopathy

Transplant glomerulopathy (TGP) appears to be a pathogenic feature of chronic antibody-mediated rejection, but the pathogenesis of this histologic entity is still poorly understood. Previous studies suggest the involvement of lymphocytes but the phenotypes of these cells have never been analyzed. Here, we report the first study of mRNAs for specific markers of CD4+ T cells including Th1 (T-bet and INFgamma), Th2 (IL4 and GATA3), Treg (Foxp3) and Th17 (IL-17 and RORgammat) subsets, cytotoxic CD8 T cells (Granzyme B) and B-cell markers (CD20) in renal biopsies from renal transplant recipients suffering interstitial fibrosis and tubular atrophy (IF/TA) with or without TGP but with a similar inflammatory score and controls including transplant recipients with normal renal function. Only INFgamma, T-bet (both functionally defined markers of Th1 CD4 T cells) and granzyme B (a CD8 cytotoxic marker) were significantly more strongly expressed in patients with TGP than in patients without TGP and normal controls. These results indicate a role of an active T-mediated inflammatory and cytotoxic process in the pathogenesis of TGP.