Amyloidosis--incidence and early risk factors in patients with rheumatoid arthritis

Prevalence of Subclinical Amyloidosis in a Cross-sectional Study of Egyptian RA Patients without Proteinuria

BACKGROUND

Amyloidosis is a life-threatening complication of Rheumatoid Arthritis (RA) that should be detected as early as possible to avoid its morbidity and mortality.

OBJECTIVE

To detect subclinical amyloidosis in RA patients without proteinuria and a disease duration more than 5 years.

PATIENTS

Eighty-six RA patients seen between October 2013 and August 2014 were recruited for the study. Those with 5 years disease duration were included in the study but those who had proteinuria, serum creatinine > 1.5 mg/dl, disease onset before the age of 16 years or improper specimens, were excluded, leaving 30 eligible patients (23 women, 7 men). The clinical, laboratory and imaging results and treatments were maintained for each patient. Abdominal Fat Aspiration Biopsy (AFAB) was performed on all 30 patients. Amyloid deposits were spotted by polarised light microscopy following Congo red staining. Informed consent was acquired from all patients. Clinical disease activity was scored according to DAS. ELISA measured serum amyloid A protein (SAA), CRP and RF.

RESULTS

AFAB stained positive for amyloid in 4 (13.3%) patients out of 30. The amyloid deposits were (1+) in 1 patient and (2+) in 3 patients. Longer RA duration correlated positively with amyloidosis (12.50 years versus 6.15years) (P < 0.001). Extra-articular manifestations were present in 50% of the amyloid patients and in 15.3% of the non-amyloid patients. This difference was significant (P < 0.01). DAS 28 score was higher in amyloid patients (P < 0.001). No difference was found between amyloid and non-amyloid patients regarding age, sex or deformities. SAA was significantly higher in amyloid patients (P < 0.001). However, haemoglobin levels were found to be significantly lower in amyloid patients (P < 0.001).

CONCLUSION

The prevalence of subclinical amyloidosis by AFAB was found to be (13.3%). The use of AFAB should be encouraged, particularly in patients with longer disease duration and low haemoglobin level to confirm early detection of subclinical amyloidosis.

Renal AA Amyloidosis in Patients with Type 2 Diabetes Mellitus

Background

Type 2 diabetes mellitus (T2DM) is the leading cause of chronic kidney disease and a major cause of cardiovascular disease (CVD) mortality. Inflammation is closely involved in the pathogenesis of T2DM, and reactive amyloidosis occurs in the presence of chronic inflammation. We hypothesized that patients with T2DM may have a higher prevalence of renal AA amyloidosis (RAAA) and that this could contribute to worse atherosclerosis and CVD.

Materials and Methods

We analyzed 330 autopsy kidneys from patients with a previous T2DM diagnosis. The kidney tissue was evaluated in order to determine the presence of diabetic nephropathy and RAAA, and systemic vessels were evaluated for the presence of atherosclerosis.

Results

RAAA was detected in 9% of our study population and was associated with an increased risk for nodular sclerosis [OR (95% CI)] [11 (2.04-59.16)], for chronic ischemic cardiomyopathy [4.59 (2.02-10.42)], for myocardial infarction [3.41 (1.52-7.64)] as well as for aortic [4.75 (1.09-20.69)], coronary [3.22 (1.47-7.04)], and intrarenal atherosclerosis [3.84 (1.46-10.09)].

Conclusions

RAAA is prevalent in T2DM and is associated with worse CVD and renal disease, likely because RAAA is a marker of severe chronic inflammation.

More evidence of declining incidence of amyloidosis associated with inflammatory rheumatic diseases

OBJECTIVE

To assess the incidence, prevalence, and outcome of amyloidosis associated with inflammatory rheumatic diseases.

METHODS

An observational study was performed in the outpatient department of Kainuu Central Hospital from 1993 to 2007. The following criteria were used for the performance of abdominal subcutaneous fat aspiration (ASFA) and/or rectal biopsies: erythrocyte sedimentation rate (ESR) > 40 mm/h at two consecutive visits; and proteinuria (> 0.5 g/day) or serum creatinine > 150 μmol/L. Renal biopsy was performed when there was a high suspicion of amyloidosis in cases with negative findings in the above-mentioned biopsies. In addition, amyloid staining was used routinely for mucosal specimens taken in gastroscopy and colonoscopy. The patients were followed until death or to the end of 2007.

RESULTS

New diagnoses of amyloidosis in the consecutive 5-year periods from 1993 onwards numbered 11, 3, and 5, respectively. During the study period, there was a mean annual incidence of amyloidosis of 1.8 [95% confidence interval (CI) 1.1-2.8)/100,000]. At the end of 2007 there were eight subjects with amyloidosis, giving a point prevalence of 12.0/100,000 (95% CI 5.2-23.6). Five patients out of the 19 underwent haemodialysis because of terminal uraemia and three of them also had renal transplantation. Overall, 12 (63%) patients died after a median survival time of 6 (95% CI 4-8) years, one-third from amyloidosis. The 5-year survival rate of the series was 67% (95% CI 41-86).

CONCLUSION

Amyloidosis is rarely encountered today. ASFA or rectal biopsy facilitates its early diagnosis.

Amyloidosis is frequently undetected in patients with rheumatoid arthritis

Prevalence of AA amyloid in rheumatoid arthritis (RA) is still unclear. The objective of this retrospective study was whether dedicated re-examination of autopsy tissues from RA patients increases the detection rate of amyloid compared to routine examination. Amyloid was re-examined in tissue samples and detection rate compared with original reports of 369 consecutively autopsied RA patients and 370 non-RA patients matched for sex, age, and year of autopsy between 1952 and 1991. Re-examination of 90% of the 739 cases showed doubling of the prevalence of amyloid compared with the original reports: from 18 to 30% in RA and from 2 to 4% in non-RA patients. In RA patients, cardiac amyloid was as frequent as renal amyloid. In RA patients with amyloid at re-examination, amyloidosis had been diagnosed before autopsy in 37%, and these patients had more inflammation and longer disease duration than RA patients without amyloid. Only 56% of RA patients with renal amyloid were known to have proteinuria. In conclusion, this autopsy study shows that amyloid in RA is a common finding which remains frequently undetected. In patients with active and long-lasting RA, a systematic search for amyloid may enable early diagnosis of amyloidosis, which will require effective suppression of inflammation.

Experimental induction of amyloidosis by bovine amyloid fibrils in Sore Hock rabbits

We report the experimental amyloidosis associated with administration of bovine amyloid fibrils in rabbits afflicted by Sore Hock (SH), which is ulcerative pododermatitis. Two groups of SH-afflicted rabbits were subjected to five inflammatory stimulations at intervals of 4 days by intraepithelial injection of a mixture consisting of Freund's complete adjuvant and lipopolysaccharide. One group of rabbits was administered amyloid in conjunction with the last inflammatory stimulation and the other group was not. For additional control, two groups were designed. A third group consisted of rabbits without SH, which were subjected to five stimulations and were administered amyloid. A fourth group consisted of SH-afflicted rabbits, subjected to 0-4 stimulations and administered amyloid. Amyloid depositions were observed in SH-afflicted rabbits, which had been stimulated five times and given amyloid (18/18). In the 4th group, only one rabbit, which had been subjected to four stimulations, showed amyloid depositions. No amyloid depositions were observed in the other rabbits. These results suggest that bovine AA amyloid fibrils have an amyloid-enhancing factor-like effect on SH-afflicted rabbits.

Gastrointestinal manifestations of amyloidosis

Amyloidosis is characterized by extracellular deposition of abnormal protein. There are six types: primary, secondary, hemodialysis-related, hereditary, senile, and localized. Primary (AL) amyloidosis is associated with monoclonal light chains in serum and/or urine with 15% of patients having multiple myeloma. Secondary (AA) amyloidosis is associated with inflammatory, infectious, and neoplastic diseases. The presentation is protean, including macroglossia, a dilated and atonic esophagus, gastric polyps or enlarged folds, and luminal narrowing or ulceration of the colon. Amyloid deposition in the gastrointestinal (GI) tract is greatest in the small intestine. The symptoms include diarrhea, steatorrhea, or constipation. Pseudo-obstruction carries a particularly grave prognosis, often not responding to pro-motility agents. Hepatic involvement is common, but the clinical manifestations are usually mild with hepatomegaly and an elevated alkaline phosphatase level. Biopsies to diagnose amyloidosis can be taken from the fat, kidney, intestine, or bone marrow. The safety of liver biopsies is controversial. With Congo Red stain, amyloid appears red in normal light and apple-green in polarized light. Treatment for AL amyloidosis is chemotherapy and stem cell transplantation; treatment for AA amyloidosis is control of the underlying disease. Amyloidosis should be considered in patients with proteinuria, cardiomyopathy, hepatomegaly (with mildly abnormal liver tests), peripheral and autonomic neuropathy, weight loss, and GI symptoms.

Acute Secondary Gastrointestinal Amyloidosis in a Patient with Rheumatoid Arthritis

Secondary amyloidosis is well recognized as a severe complication in the late stages of rheumatoid arthritis (RA). However, there have been few reported cases of secondary amyloidosis developing early during the course of RA. We here report the case of a 35-year-old woman, in whom RA who had been diagnosed 1 year before, with intractable watery diarrhea as a symptom of RA-induced secondary intestinal amyloidosis. Combination treatment with intravenous hyperalimentation, corticosteroids, and methotrexate (MTX) resulted in a dramatic improvement of her symptoms and objective findings of serological abnormalities. Subsequent administration of corticosteroids and MTX resulted in long-term survival without recurrence. This case indicates that we should be alert for the development of secondary amyloidosis, even in patients with a short history of RA, when the disease is active. Furthermore, combination therapy with intravenous hyperalimentation and strong immunosuppressive agents seems to be very efficacious in the treatment of RA-associated secondary intestinal amyloidosis.

Screening for amyloid in subcutaneous fat tissue of Egyptian patients with rheumatoid arthritis: clinical and laboratory characteristics

OBJECTIVE

To screen for amyloid and to assess associated clinical and laboratory characteristics in Egyptian patients with rheumatoid arthritis (RA).

METHODS

Abdominal subcutaneous fat aspirates were consecutively collected from 112 patients (103 women, nine men) having RA for five years or more. To detect amyloid, fat smears were stained with Congo red and the concentration of amyloid A protein in fat tissue was measured. Clinical, radiological, and laboratory characteristics of the patients were assessed.

RESULTS

Amyloid was detected in eight (7%) of the fat smears stained with Congo red. Compared with the Congo red stain, the sensitivity for detecting amyloid by measurement of amyloid A protein in fat tissue was 75% and the specificity was 100%. The amount of amyloid found was small for both methods. The median disease duration of the eight amyloid patients was significantly longer (17 years) than that of the non-amyloid patients (10 years). Bronchopulmonary disease and constipation were more common, whereas proteinuria and chronic renal insufficiency were not. The number of swollen joints and the number of red blood cells were significantly lower in the amyloid group.

CONCLUSIONS

Quantification of amyloid A protein and staining with Congo red are strongly concordant methods of screening for amyloid in fat tissue. The prevalence of amyloid in Egyptian patients with RA is 7%. Proteinuria is not a discriminating feature, whereas long disease duration, constipation, bronchopulmonary symptoms, and a moderate to low number of red blood cells may help to identify the arthritic patients with amyloid.

The clinical significance of amyloid fat deposits in rheumatoid arthritis: a systematic long-term followup study using abdominal fat aspiration

OBJECTIVE

To analyze the prevalence of subclinical amyloid fat deposits in patients with rheumatoid arthritis (RA) and to evaluate its clinical significance.

METHODS

A cohort of 313 adult RA patients were included in this prospective observational study. Systematic abdominal subcutaneous fat aspiration (ASFA) was performed on all patients at study entry. The prevalence of visceral amyloidosis at study entry and at the end of followup was analyzed for patients with a positive ASFA test result. Followup ranged from 1 to 14 years (mean +/- SD 6.7 +/- 4.1 years). Patients with clinical and subclinical amyloidosis were compared with regard to clinical characteristics and the degree of amyloid deposits in abdominal fat.

RESULTS

The first ASFA test found amyloid in the abdominal fat of 51 patients (16.3%), and subsequent ASFA tests found amyloid in the abdominal fat of 10 additional patients. At the time of the ASFA test, amyloidosis was subclinical in 45 of these 61 patients, 41 of whom were followed up. During followup, 11 of these 41 patients developed renal involvement, 5 due to amyloid nephropathy. Thus, amyloidosis remained subclinical in at least 30 of 41 patients (73%) throughout followup. Marked amyloid fat deposits were found more frequently in patients with clinical amyloidosis than in those whose amyloidosis remained subclinical at the end of followup (57% versus 22%; P = 0.04).

CONCLUSION

Amyloid fat deposits are not uncommon in adult RA. In the majority of patients, the deposits do not indicate clinically evident organic dysfunction, even after several years of followup. Patients with more extensive fat deposits may have a higher risk of developing clinical amyloidosis.

Serum C-reactive protein is rarely lost into urine in patients with secondary amyloidosis and proteinuria

We studied whether the low serum C-reactive protein (S-CRP) level in patients with inflammatory arthritis and proteinuria was due to the loss of CRP into urine. In 19 patients with secondary amyloidosis (14 with rheumatoid arthritis and five with juvenile chronic arthritis), S-CRP was measured with both immunoturbidimetric and radioimmunoassays. The concentration of urinary CRP was measured with a double-antibody radioimmunoassay. One patient with the most extensive proteinuria (12 g/24 h) excreted CRP at 14 mg/24 h, while in 18 of 19 patients only negligible, if any, amounts of CRP were found in 24-h urine samples. Proteinuria of < 8 g/24 h did not reduce the S-CRP level. Proteinuria exceeding this level may result in increased excretion of CRP into urine and consequently may result in a reduced S-CRP level.

Intractable diarrhoea associated with secondary amyloidosis in rheumatoid arthritis

OBJECTIVE

To examine the clinical characteristics of intractable diarrhoea associated with secondary amyloidosis in rheumatoid arthritis (RA).

METHODS

Of 179 RA patients with biopsy confirmed secondary amyloidosis, 24 cases (23 women and one man) with intractable diarrhoea lasting for more than one month were retrospectively evaluated.

RESULTS

The mean (SD) duration of diarrhoea was 87 (64) days. Prodromal symptoms of gastrointestinal dysfunction (n = 21) and impaired peristalsis (n = 16) were observed. Laboratory data showed hypoproteinaemia (4.7 (0.85) g/dl) caused by malabsorption or protein loss and high values of C reactive protein (17.0 (9.3) mg/dl). Recurrence of intractable diarrhoea (n = 4) and transition from intractable diarrhoea to other gastrointestinal problems of amyloidosis (ischaemic colitis (n = 2) and intestinal pseudo-obstruction (n = 4)) were observed. In 19 patients (25 episodes) the duration of intravenous hyperalimentation at remission (18 episodes) was 68 (52) days. Corticosteroid pulse therapy was administered to 10 patients (11 times) and the time elapsed from the end of corticosteroid pulse therapy to the end of diarrhoea was 18 (14) days. One and five year survival rates after the onset of intractable diarrhoea were 73.4% and 38.9%. Seven of 13 patients (54%) had died as a result of infectious diseases.

CONCLUSION

Intractable diarrhoea associated with secondary amyloidosis in RA is a serious clinical entity and the prognosis is poor. Although it is assumed that intravenous hyperalimentation treatment and corticosteroid pulse therapy are favourable regimens for intractable diarrhoea, the patients should be monitored for possible infectious complications.

High prevalence of serum apolipoprotein E4 isoprotein in rheumatoid arthritis patients with amyloidosis

OBJECTIVE

To determine whether serum Apolipoprotein E (Apo E) type 4 isoprotein is a risk factor for the development of amyloidosis in patients with rheumatoid arthritis (RA).

METHODS

Using isoelectric focusing, we studied Apo E phenotype expression and the corresponding allele frequencies (epsilon 2, epsilon 3, and epsilon 4) in 35 patients with RA and amyloidosis, 65 patients with RA and without amyloidosis, and 63 healthy controls.

RESULTS

The Apo E3/4 phenotype was significantly more common in the group with amyloidosis (31.4%) than in the patients without amyloidosis (12.3%; P < 0.05) or in healthy controls (12.7%; P < 0.05). The frequency of the epsilon 4 allele was significantly greater in the group with amyloidosis (0.16) than in the patients without amyloidosis (0.07; P < 0.05) or in healthy controls (0.07; P < 0.05).

CONCLUSION

The presence of Apo E4 isoprotein may be a risk factor for the development of amyloidosis in patients with RA.

Clinical and therapeutic aspects of AA amyloidosis

Approach to the management of AA amyloidosis complicating RA. (A) In case of proteinuria or loss of renal function a rectal biopsy or a subcutaneous fat biopsy is a suitable screening method for the detection of amyloidosis. If in any doubt, try to ascertain the diagnosis by renal biopsy. Adequate staining with alkaline Congo red and preferably immunohistochemical staining with anti-AA antibodies should be performed. Beware of renal pathology other than amyloidosis even in the presence of a positive rectal biopsy. (B) A vigorous attempt to control disease activity of the RA should be made in order to eliminate the production of SAA, an acute phase protein. The response to treatment should be monitored by serial measurements of CRP and preferably SAA. (C) The function of some vital organs should be evaluated: (a) endogenous creatinine clearance and the extent of proteinuria; (b) electrocardiogram and optional echocardiography; (c) thyroid function and adrenocortical function; (d) intestinal absorption tests; (e) optional--SAP scintigraphy and turnover studies. (D) Attention should be given to adequate supportive treatment: (a) blood pressure control; (b) treatment of intercurrent infections; (c) corticosteroids during major surgical procedures; (d) pay attention to the possible effect of NSAID on proteinuria and renal function. (E) In case of total renal failure or uncontrollable proteinuria: (a) consider the possibility of primary renal transplantation; (b) otherwise regular haemodialysis is indicated.