From renal amyloid deposits to the identification of the culprit genes

Hereditary amyloidoses with renal involvement are classified in two groups. The first group is a growing family of autoinflammatory disorders characterized by recurrent fever attacks. Amyloidosis is caused by the deposition of amyloid A (AA) protein, which is a degradation product of a normal serum acute-phase protein: serum amyloid A (SAA). The prototype is familial Mediterranean fever (FMF). TNF Receptor Associated Periodic Syndrome (TRAPS) is a recently recognized periodic fever syndrome, differing from FMF in several characteristics: autosomal-dominant transmission, longer duration of attacks, and lack of response to colchicine prophylaxis. The second group comprises a variety of disorders, each characterized by the deposition of a specific mutant protein. The prototype is transthyretin amyloidosis (TTR). Identification of the form of amyloidosis has clinical implications. Therefore, in a patient with a history of recurrent fever attacks and AA amyloidosis, a diagnosis of FMF or TRAPS dictates appropriate genetic counseling and management. In patients with renal amyloidosis without a history of fever, identification of the mutant protein is therapeutically crucial; therefore, when the cell type that produces the precursor is (exclusively or mainly) the hepatocyte, a liver transplantation is to be considered.     

Crescentic glomerulonephritis in hyper IgD syndrome

 The hyperimmunoglobulinemia D syndrome (HIDS) is a well-defined entity resembling familial Mediterranean fever. HIDS is a systemic inflammatory disease associated with stimulation of T-cell-mediated immunity. These patients are at low risk for amyloidosis and are not known to develop nephropathy. We report a boy of Mediterranean ancestry who exhibited typical HIDS and end-stage renal failure. Kidney biopsy revealed pauci-immune crescentic glomerulonephritis (cGN). We hypothesized that the glomerular involvement was secondary to the cytokine network activation observed in HIDS. Thus, cGN should be considered as part of the syndrome, and kidney biopsy should be performed early in the course of the renal disease in patients with HIDS. Received: 2 February 1998 / Revised: 30 June 1998 / Accepted: 2 July 1998     

Familial Mediterranean fever in Mexico City. A 20-year follow-up

Familial Mediterranean fever (MFF) is an autosomic recessive, inherited inflammatory disease principally seen in persons from the Mediterranean area. Clinical findings include fever, abdominal pain, and pleuritis. The most severe complication of MFF is renal amyloidosis, manifested as nephrotic syndrome, which evolves into chronic renal failure. In this study, we described clinical findings, evolution, and response to treatment in 52 patients diagnosed with MFF living in Mexico City in whom the most important clinical features were fever and abdominal pain. Differing from previous reported series of patients from the Mediterranean area, patient developed renal amyloidosis during the 20-year follow-up, which suggests that an environmental factor might have a significant influence in development of renal amyloidosis.     

AA type renal amyloidosis secondary to FMF: a long-term follow-up in two patients

Renal amyloidosis, which leads to renal failure, is the most important long-term complication of familial Mediterranean fever (FMF). Resolution of nephrotic syndrome secondary to amyloidosis in FMF following colchicine treatment has rarely been reported. We describe two patients with FMF and nephrotic syndrome. These patients were treated with colchicine 1.5 mg/day and had a complete remission of nephrotic syndrome with a stable clinical course over 30 years. To our knowledge, our patients have the longest follow-up time without proteinuria.     

AA type renal amyloidosis secondary to FMF: a long-term follow-up in two patients

Renal amyloidosis, which leads to renal failure, is the most important long-term complication of familial Mediterranean fever (FMF). Resolution of nephrotic syndrome secondary to amyloidosis in FMF following colchicine treatment has rarely been reported. We describe two patients with FMF and nephrotic syndrome. These patients were treated with colchicine 1.5 mg/day and had a complete remission of nephrotic syndrome with a stable clinical course over 30 years. To our knowledge, our patients have the longest follow-up time without proteinuria.     

Familial Mediterranean fever and IgA nephropathy: case report and review of the literature

Familial Mediterranean fever (FMF) is the most common form of autoinflammatory syndromes and is characterized by recurrent inflammatory attacks of fever and serositis. Amyloidosis is the most common renal complication of FMF. In addition to amyloidosis, many renal lesions have been anecdotally reported in patients with FMF and other hereditary periodic fevers. We report a Turkish child with FMF presenting with hematuria during attacks, in whom kidney biopsy documented the presence of mesangial IgA deposits and the absence of amyloidosis. Kidney biopsy should be performed in patients showing microscopic or gross hematuria during attacks of familial Mediterranean fever in order to gain additional epidemiological data about specific features of renal involvement and to allow adequate treatment.     

Autosomal-dominant periodic fever with AA amyloidosis: Novel mutation in tumor necrosis factor receptor 1 gene Rapid Communication

BACKGROUND: The recent identification of genes responsible for syndromes of periodic fever with amyloidosis has opened the way to a molecular diagnosis of hereditary AA amyloidosis. METHODS: A Belgian woman presented for genetic counseling. Three first-degree relatives had a diagnosis of renal amyloidosis with a history of recurrent fever and inflammatory episodes. Medical records and pathological specimens were obtained from all physicians who had been in charge of her three relatives. Immunohistochemical staining was performed on paraffin-embedded material. A mutation search was performed in the MEFV (Mediterranean fever) and tumor necrosis factor receptor 1 (TNFR1 or TNFRSF1A) genes causing familial Mediterranean fever (FMF) and tumor necrosis factor receptor-associated periodic syndrome (TRAPS), respectively. RESULTS: The family history was consistent with autosomal-dominant transmission of periodic fever with arthralgias, abdominal pain, and eventual AA amyloidosis involving the kidneys, digestive tract, and thyroid. Recurrent amyloidosis in kidney graft was demonstrated in one patient and was suspected in the other. A novel heterozygous mutation (C55S) in TNFRSF1A was identified in the affected patient available for genetic testing but not in the asymptomatic woman requiring counseling. No mutation was detected in MEFV. CONCLUSIONS: We report a novel mutation (C55S) in TNFRSF1A, resulting in autosomal-dominant periodic fever and AA amyloidosis. This condition, known as TRAPS, should be added to the differential diagnosis of hereditary renal amyloidosis, with obvious implications for management and genetic counseling.     

Familial Mediterranean fever (FMF) and renal AA amyloidosis--phenotype-genotype correlation,treatment and prognosis

Familial Mediterranean fever (FMF) is an autosomal recessive disease, which primarily affects the population surrounding the Mediterranean basin. It is characterized by recurrent attacks of fever and peritonitis, pleuritis, arthritis or erysipelas-like erythema. Amyloidosis, causing renal failure, is one of the most severe complications of the disease. The gene associated with FMF (MEFV) has been recently isolated. Phenotype-genotype correlation studies revealed that amyloidosis was more common in FMF patients originating from North-Africa who were homozygous for the M694V mutation. Such a correlation was not found in Turkish patients. The risk of amyloidosis is increased in male FMF patients and in patients bearing polymorphism a/a in the SAA1 gene. Colchicine is the chosen drug for the treatment of FMF and can prevent amyloidosis.     

Rapid progressive glomerulonephritis in patients with familial Mediterranean fever

Two patients with a long-standing history of familial Mediterranean fever (FMF) presented with gross hematuria, oliguria, and acute renal failure; both required dialysis support. Kidney biopsies from both patients revealed crescentic rapid progressive glomerulonephritis (RPGN) without amyloidosis. One patient recovered renal function with methylprednisolone pulse therapy and cyclophosamide. The second patient did not improve and required regular hemodialysis. He is asymptomatic on colchicine therapy. To our knowledge, these are the first cases documenting the presence of RPGN in patients with FMF.     

Mesangial proliferative glomerulonephritis in familial Mediterranean fever patient with E148Q mutation: the first case report

Familial Mediterranean fever (FMF) is an autosomal recessive hereditary disease characterized by recurrent attacks of fever, usually accompanied by sterile polyserositis. Although amyloidosis is the most common renal involvement, non-amyloid renal lesions, such as glomerulonephritis, have been described in patients with FMF. In this report, we present the first case of an FMF patient with heterozygous mutation of E148Q, mesangial proliferative glomerulonephritis, and no amyloidosis. While the association of mutation E148Q with renal involvement is still obscure, colchicine treatment is useful in mesangial proliferative glomerulonephritis with FMF.     

Variable expression of vasculitis in siblings with familial Mediterranean fever

Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterized by recurrent and self-limited attacks of serosal inflammation with abdominal pain, chest pain, and arthritis usually accompanied by fever. Different vasculitides such as polyarteritis nodosa (PAN) and Henoch-Schönlein syndrome (HSS) may be associated with FMF. We report two sisters of a Turkish family with FMF who developed distinct vasculitides. The younger sister developed severe PAN with perirenal hematoma at the age of 13 years, the older sister presented with severe HSS and acute renal failure at the age of 19 years. Neither sister developed amyloidosis until the age of 30 years. This observation suggests that early events in the pathogenesis of PAN and HSS are generally quite similar.     

Phenotype 2 Familial Mediterranean Fever: Evaluation of 22 Case Series and Review of the Literature on Phenotype 2 FMF

Familial Mediterranean fever (FMF) is an autosomal recessive autoimmune disorder characterized by recurrent bouts of fever and serosal inflammation. FMF may be complicated by AA-type amyloidosis, worsening the prognosis, with associated renal failure in some patients. Complication rate varies with race, being as high as 60% in Turks and as low as 2% in Armenians. In a few cases of patients with FMF (phenotype 2), amyloid nephropathy may be the presenting manifestation. This study included 420 patients who were admitted to the Nephrology and Rheumatology Departments of Atatürk Education and Research Hospital with unexplained proteinuria/nephrotic syndrome. The initial screening test for amyloidosis was the presence of significant proteinuria (300 mg/24 h). All MEFV gene exons were screened for causative mutations by direct DNA sequencing to check for any mutations. There were 22 phenotype 2 FMF patients with 27 allelic variants. The most prevalent allelic variants were M694V (10/27, 37%) and E148Q (7/27, 26%). Phenotype 2 FMF is not as rare as it was thought before; this should be kept in mind for all patients with unexplained proteinuria and/or acute phase response in high-risk ethnic groups for FMF.     

The influence of indomethacin on renal acidification in normal subjects and in patients with sickle cell anemia

Patients with sickle cell nephropathy have been shown to have a distal type of incomplete renal tubular acidosis. We evaluated renal tubular acidification before and after indomethacin administration because prostaglandins have been shown to inhibit the transepithelial potential difference in the collecting tubule and since we previously found indirect evidence of increased prostaglandin synthesis in patients with sickle cell nephropathy. Indomethacin did not change urine pH in the sickle cell anemia (SCA) patients or in the control subjects. It induced, however, an increase in titratable acid excretion particularly in the SCA patients. Ammonium excretion decreased after indomethacin in the SCA patients while it did not change significantly in the control subjects. In the SCA patients, net acid excretion did not rise after indomethacin. In contrast there was an increase in net acid excretion after indomethacin administration in the control subjects. We conclude from our study that the inability of patients with SCA to lower urine pH to a normal extent after ammonium chloride loading is not improved by indomethacin. The decrease in ammonium excretion after indomethacin administration in SCA might be due to an effect of the prostaglandin synthesis inhibitor indomethacin on ammoniagenesis.     

Mutational spectrum in the MEFV and TNFRSF1A genes in patients suffering from AA amyloidosis and recurrent inflammatory attacks.

BACKGROUND: Among hereditary fevers characterized by recurrent attacks of fever and organ localized inflammation, familial Mediterranean fever (FMF), and tumour necrosis factor receptor superfamily 1A (TNFRSF1A) receptor associated periodic syndrome (TRAPS) are diseases with identified genes that can be associated with renal amyloidosis of the AA type. In this study we have characterized FMF and TRAPS genotypes in 38 unrelated patients suffering from amyloidosis AA and recurrent inflammatory attacks. METHODS: Mutations of the MEFV and TNFRSF1A genes, responsible respectively for FMF and TRAPS, were searched for by amplifying, using polymerase chain reaction (PCR), genomic DNA, and direct sequencing. RESULTS: Twenty-seven patients (71%) carried mutations in MEFV (22 patients with two mutations, two patients with a single mutation) or TNFRSF1A genes (three patients). Patients with MEFV mutations belonged to the classical at-risk ethnic group for FMF: Sephardic Jews, Turks, Armenians, and Arabs from the Maghreb. The main genotype encountered was M694V/M694V (19/22), one Turkish patient was M680I/M680I, and two Arab patients from the Maghreb were M694I/M694I. We found three Caucasian patients with the C55S, C70Y, R92Q mutations in the TNFRSF1A gene. CONCLUSIONS: In this series we observed that FMF is the main cause of AA amyloidosis in Sephardic Jews and Turks. MEFV and TNFRSF1A mutations were found in only 6 of 14 Arab patients from the Maghreb. We found three families (one Caucasian and two from Maghreb) with AA amyloidosis without MEFV or TNFRSF1A mutations, suggesting that other genetic cause(s) exist(s). The characterization of mutations in MEFV and TNFRSF1A is important for the therapeutic behaviour of AA amyloidosis associated with inherited recurrent fever.     

Amyloidosis of the kidneys. Review of patients and literature.

The clinical findings in 49 patients (27 males) who had histologically confirmed amyloidosis of the kidney, are reviewed. In 28 patients, the diagnosis was arrived at by percutaneous renal biopsy, and in 21 patients it was made at autopsy. The youngest patient was diagnosed at the age of 16 years. In 11 patients (22,5%) no associated disease was found, in a further 11 patients the amyloidosis was of the type connected with familial Mediterranean fever, and in 27 patients (55%) the amyloidosis was of the secondary type. Forty-six patients (94%) presented with proteinuria at some stage of their disease. Twenty-one patients developed the nephrotic syndrome. Thirty-two patients died, and in 18 instances uraemia was the cause of death. In 18 patients there was evidence of renal pathology other than amyloidosis, and in some patients this may have contributed to the impairment of renal function and the appearance of proteinuria.     

Cardiac and intestinal amyloidosis in a renal transplant recipient with familial Mediterranean fever.

In Turkey, familial Mediterranean fever (FMF) is an important cause of nephrotic syndrome and endstage renal disease due to renal deposition of AA type amyloid. We report a case of living-related donor renal transplant recipient with FMF and renal AA type amyloidosis, who died of progressive heart failure due to cardiac involvement. The patient also had intractable diarrhea caused by biopsy-proven intestinal amyloidosis. The patient was on 1 mg/day colchicine. Although he was attack-free throughout the post-transplant period, intestinal and clinically significant cardiac amyloidosis, which implied the presence of sustained inflammation and continuing amyloid deposition, appeared three years after renal transplantation. Cardiac deposition of AA amyloid may cause clinically significant heart disease, leading to cardiovascular mortality after renal transplantation for end-stage renal disease in FMF patients.     

A Case with Acute Renal Failure and Subsequent Nephrotic Syndrome

Nephrotic syndrome due to secondary amyloidosis is not so common, and the prognosis depends on primary disease. We report a case of secondary amyloidosis caused by Takayasu's arteritis. Sustained high fever and acute renal failure proceeded to the occurrence of nephrotic syndrome. Secondary amyloidosis was diagnosed by renal biopsy before the diagnosis of primary disease. She was completely recovered from nephrotic syndrome after two years' treatment with prednisolone, aspirin, and dimethyl sulfoxide. This rare case provides meaningful suggestions for the diagnosis and treatment of acute renal failure and nephrotic syndrome caused by secondary amyloidosis.     

Outcomes of Canakinumab Treatment in Recipients of Kidney Transplant With Familial Mediterranean Fever: A Case Series

Familial Mediterranean fever (FMF) is an important and preventable cause of chronic kidney disease due to secondary amyloidosis. Although colchicine is the first-line therapy in patients with FMF with 60% to 65% complete remission rates, 5% to 10% of patients are colchicine-resistant and 5% to 10% of them are intolerant to the therapy. Anti–interleukin-1 agents, such as anakinra and canakinumab, are safe and efficient therapeutic options in patients with colchicine resistance or intolerance. However, the data on management of these targeted agents is limited in recipients of kidney transplant (RKT). In this case series, we aim to share our experience on canakinumab therapy of 4 RKTs with FMF-related amyloidosis, who were followed up in our clinic between 2010 and 2017. All of the 4 patients with end-stage renal disease were colchicine- resistant and on other alternative therapies, which provided poor disease control. For efficient control of secondary amyloidosis, canakinumab therapy was initiated in 1 of the patients before the renal transplant, and for the remaining patients after renal transplant. Any serious adverse effect, development of proteinuria, or graft dysfunction has not been observed in any of the patients. Under the canakinumab treatment, complete clinical responses, prevent typical familial Mediterranean fever attacks with fever and arthritis and abdominal pain, normalized serum amyloid A and C-reactive protein levels were achieved in all patients. Canakinumab treatment is a safe and effective therapeutic option for RKTs with FMF who are resistant or intolerant to colchicine and anakinra.     

IgA nephropathy in patients with familial Mediterranean fever

Two patients with a long-standing history of familial Mediterranean fever were found to have both microscopic hematuria and proteinuria during the acute attacks. Kidney biopsies from both patients revealed diffuse mesangial proliferative glomerulonephritis with intense mesangial IgA and C3 deposits and no evidence of amyloidosis. To our knowledge these are the first 2 cases documenting the presence of mesangial IgA nephropathy in patients with familial Mediterranean fever.     

Renal amyloidosis followed more than 5 years: report of 12 cases

Renal involvement with amyloidosis is common but causes patient survival to be poor, rarely reaching 5 years. In this study, we retrospectively reviewed clinical and biological characteristics as well as treatments and outcomes of patients with renal amyloidosis followed for more than 5 years. Between 1975 and 2003, 485 patients were diagnosed with renal amyloidosis including only 12 patients who were followed more than 5 years. The six men and six women of mean age 42.4 years (range 18 to 66 years) displayed renal signs of lower limb edema in all cases; hypertension in four cases, proteinuria on urinalysis in all cases with microscopic hematuria in five cases. Biological tests showed nephrotic syndrome in 11 patients, normal renal function in nine patients, and renal failure in three patients whose mean creatinine was 481.6 micromol/L (range 294 to 726). The amyloidosis was AA type in 11 cases and non-AA in one case. An etiologic survey revealed spondylarthropathy in one patient, pulmonary tuberculosis in two patients, chronic bronchitis in three patients, hepatic hydatic cyst in one patient, Mediterranean familial fever in two patients, Crohn's disease in one patient, Hodgkin's lymphoma in one patient, and multiple myeloma in one patient. Specific treatment was initiated with colchicine in seven patients. At a 110-month mean follow-up (range 53 to 153 months), remission of nephrotic syndrome was observed in four cases, progression to chronic renal failure in two patients, and to end-stage renal failure in five cases (range 53 to 196 months), with stabilization of renal function in seven patients. In conclusion, primary amyloid disease should be optimally suppressed in patients with renal involvement. The role of this treatment in remission of renal amyloidosis is not well established. This efficacy of the treatment has been demonstrated in some patients with improved survival.