Intractable diarrhoea associated with secondary amyloidosis in rheumatoid arthritis

Gastrointestinal amyloidosis: A focused review

Amyloidosis, a heterogenous group of disorders, is characterized by the extracellular deposition of autologous, insoluble, fibrillar misfolded proteins. These extracellular proteins deposit in tissues aggregated in ß-pleated sheets arranged in an antiparallel fashion and cause distortion to the tissue architecture and function. In the current literature, about 60 heterogeneous amyloidogenic proteins have been identified, out of which 27 have been associated with human disease. Classified as a rare disease, amyloidosis is known to have a wide range of possible etiologies and clinical manifestations. The exact incidence and prevalence of the disease is currently unknown. In both systemic and localized amyloidosis, there is infiltration of the abnormal proteins in the layers of the gastrointestinal (GI) tract or the liver parenchyma. The gold standard test for establishing a diagnosis is tissue biopsy followed by Congo Red staining and apple-green birefringence of the Congo Red-stained deposits under polarized light. However, not all patients may have a positive tissue confirmation of the disease. In these cases additional workup and referral to a gastroenterologist may be warranted. Along with symptomatic management, the treatment for GI amyloidosis consists of observation or localized surgical excision in patients with localized disease, and treatment of the underlying pathology in cases of systemic amyloidosis. In this review of the literature, we describe the subtypes of amyloidosis, with a primary focus on the epidemiology, pathogenesis, clinical features, diagnosis and treatment strategies available for GI amyloidosis.

A Rare Cause of Intestinal Pseudo-obstruction: Gastrointestinal Amyloid

Amyloidosis is characterized by extracellular deposition of the amyloid protein. It can affect multiple organ systems but it most commonly affects the heart, kidney and gastrointestinal (GI) tract. It can occur sporadically or in association with other conditions like multiple myeloma, chronic inflammatory diseases, infections etc. Its involvement of the gastrointestinal tract is rare and diffuse. It has variable manifestations in GI tract from involving the stomach to the large bowel including liver. We present a case of 55 year old Caucasian male with recent diagnosis of multiple myeloma who presented with recurrent episodes of small bowel obstruction which was later found to be caused by amyloid deposition.

Significant association between renal function and area of amyloid deposition in kidney biopsy specimens in both AA amyloidosis associated with rheumatoid arthritis and AL amyloidosis

The kidney is a major target organ for systemic amyloidosis, which results in proteinuria and an elevated serum creatinine level. The clinical manifestations and precursor proteins of amyloid A (AA) and light-chain (AL) amyloidosis are different, and the renal damage due to amyloid deposition also seems to differ. The purpose of this study was to clarify haw the difference in clinical features between AA and AL amyloidosis are explained by the difference in the amount and distribution of amyloid deposition in the renal tissues. A total of 119 patients participated: 58 patients with an established diagnosis of AA amyloidosis (AA group) and 61 with AL amyloidosis (AL group). We retrospectively investigated the correlation between clinical data, pathological manifestations, and the area occupied by amyloid in renal biopsy specimens. In most of the renal specimens the percentage area occupied by amyloid was less than 10%. For statistical analyses, the percentage area of amyloid deposition was transformed to a common logarithmic value (Log₁₀%amyloid). The results of sex-, age-, and Log₁₀%amyloid-adjusted analyses showed that systolic blood pressure (SBP) was higher in the AA group. In terms of renal function parameters, serum creatinine, creatinine clearance (Ccr) and estimated glomerular filtration rate (eGFR) indicated significant renal impairment in the AA group, whereas urinary protein indicated significant renal impairment in the AL group. Pathological examinations revealed amyloid was predominantly deposited at glomerular basement membrane (GBM) and easily transferred to the mesangial area in the AA group, and it was predominantly deposited at in the AL group. The degree of amyloid deposition in the glomerular capillary was significantly more severe in AL group. The frequency of amyloid deposits in extraglomerular mesangium was not significantly different between the two groups, but in AA group, the degree amyloid deposition was significantly more severe, and the deposition pattern in the glomerulus was nodular. Nodular deposition in extraglomerular mesangium leads to renal impairment in AA group. There are significant differences between AA and AL amyloidosis with regard to the renal function, especially in terms of Ccr, eGFR and urinary protein, even after Log10%amyloid was adjusted; showing that these inter-group differences in renal function would not be depend on the amount of renal amyloid deposits. These differences could be explained by the difference in distribution and morphological pattern of amyloid deposition in the renal tissue.

Inflammatory arthritis complicated by inflammatory bowel disease: two case reports

Coexistence of inflammatory arthritis disease and inflammatory bowel disease (IBD) is often considered to be relatively rare, and the underlying mechanisms of the association between them remain unclear. Herein, we report two cases of IBD which occurred during the course of inflammatory arthritis disease. The first case had psoriatic arthritis (PsA) for two and a half years complicated by Crohn's disease and accompanied by inactive carrier state of hepatitis B. The second case had rheumatoid arthritis (RA) complicated by ulcerative colitis four years after the onset of RA. In both cases, colonoscopy was performed, and their clinical presentations improved with a multidisciplinary approach. In the event of complaints related to the gastrointestinal tract in patients with PsA or RA, IBD should be kept in mind, and the clinical evaluation and multidisciplinary interventions should be planned to control the underlying autoimmune process.

Malabsorption Secondary to Gout-Induced Amyloidosis

Many chronic inflammatory conditions can lead to systemic amyloidosis. However, secondary amyloidosis has rarely been associated with gout, and the literature reports only a handful of cases, all presenting with renal disease. We report a patient with a history of poorly controlled gout who presented with malabsorption. Endoscopic biopsies confirmed a diagnosis of small intestinal amyloidosis. This was believed to be a consequence of gout. Interestingly, renal involvement was subclinical. Our case raises awareness of this rare association and highlights the importance of considering a diagnosis of amyloidosis in patients who present with the combination of gout and gastrointestinal symptoms.

Intestinal amyloidosis with intractable diarrhea and intestinal pseudo-obstruction

We report herein a case of intestinal amyloidosis with grave prognosis that caused intractable diarrhea and intestinal pseudo-obstruction, alternately in spite of intensive conservative treatment. A 44-year-old woman was admitted for fever, diarrhea, and crampy abdominal pain which had been continuned during 6 months. Abdomen CT scan showed edematous wall thickening of the small bowel and right colon, and colonoscopic biopsy revealed amyloid deposition in the mucosa. Monoclonal light chains in serum and/or urine were not detected and highly elevated serum amyloid A was shown. In spite of intensive treatment including oral prednisolone and colchicine, diarrhea and intestinal pseudo-obstruction developed alternately, general status rapidly got worsened and died after two months.

Successful treatment of protein-losing enteropathy due to AA amyloidosis with octreotide in a patient with rheumatoid arthritis

Protein-losing enteropathy (PLE) is a rare syndrome of gastrointestinal protein loss that may complicate a variety of diseases. This excessive protein loss across the gut epithelium can be explained by several mechanisms, such as augmentation of the intestinal mucosal capillary permeability, mucosal disruption, intestinal or mesenteric vasculitis, and lymphangiectasia. However, these pathophysiologic alterations of the gut are closely linked to the underlying cause, and primary treatment for PLE should be directed at the underlying condition. Here, we report a female patient with rheumatoid arthritis who developed severe PLE due to AA amyloidosis and was successfully treated with octreotide. She had been suffered from rheumatoid arthritis for 18 years, and her arthritic symptoms at the time of presentation were not definite but manifested as severe diarrhea and general edema with hypoalbuminemia. PLE due to gastrointestinal amyloidosis was confirmed by increased fecal α1-antitrypsin clearance and a colonoscopic biopsy that was positive for amyloid deposits. The diarrhea dissipated with conventional treatment, but the general edema resolved only after introducing a long-acting somatostatin analog (octreotide), along with a gradual recovery of the serum albumin level. This case teaches us that in the case of PLE due to AA amyloidosis that is refractory to conventional treatment, the administration of octreotide should be considered.

Treatment with Biologic Agents Improves the Prognosis of Patients with Rheumatoid Arthritis and Amyloidosis

Objective.

Reactive amyloid A (AA) amyloidosis is a serious and life-threatening systemic complication of rheumatoid arthritis (RA). We evaluated the safety of therapy with anti-tumor necrosis factor and anti-interleukin 6 biologic agents in RA patients with reactive AA amyloidosis, together with prognosis and hemodialysis (HD)-free survival, in comparison with patients with AA amyloidosis without such therapy.

Methods.

One hundred thirty-three patients with an established diagnosis of reactive AA amyloidosis participated in the study. Clinical data were assessed from patient records at the time of amyloid detection and administration of biologics. Survival was calculated from the date when amyloid was first demonstrated histologically or the date when biologic therapy was started until the time of death or to the end of 2010 for surviving patients. Patients who had started HD were selected for inclusion only after the presence of amyloid was demonstrated.

Results.

Fifty-three patients were treated with biologic agents (biologic group) and 80 were not (nonbiologic group). Survival rate was significantly higher in the biologic group than in the nonbiologic group. Nine patients in the biologics group and 33 in the nonbiologic group started HD. Biologic therapy had a tendency for reduced risk of initiation of HD without any statistical significance.

Conclusion.

Patients with amyloidosis have a higher mortality rate, but the use of biologic agents can reduce risk of death. The use of biologics may not significantly influence the HD-free survival rate.

Significant association between renal function and area of amyloid deposition in kidney biopsy specimens in reactive amyloidosis associated with rheumatoid arthritis

The kidney is a major target organ for systemic amyloidosis, resulting in proteinuria and an elevated serum creatinine level. In patients with reactive amyloidosis associated with rheumatoid arthritis, a correlation between the amount of amyloid deposits and clinical parameters is not known. The purpose of this study was to clarify the association between various factors including renal function and the area of amyloid deposition in these patients. Fifty-eight patients with an established diagnosis of reactive AA amyloidosis were studied. We retrospectively investigated the correlation between clinical data and the area occupied by amyloid in renal biopsy specimens. All the patients showed amyloid deposits in renal tissues, and the percentage of the area occupied by amyloid was <10% in 54 of them. Mesangial proliferative glomerulonephritis and membranous nephropathy were frequently combined with renal amyloidosis. For statistical analyses, the percentage of the area occupied by amyloid was transformed to a common logarithmic value (Log(10) % amyloid), as the histograms showed a log-normal distribution. Log(10) % amyloid was found to be correlated with age, creatinine (Cr) level, creatinine clearance (Ccr), blood urea nitrogen (BUN) level, and the estimated glomerular filtration rate (eGFR). Multiple linear regression analyses were then performed to examine the sex- and age-adjusted association between Log(10) % amyloid and each of the clinical variables. Cr, Ccr, BUN, UA, CRP, and eGFR were significantly correlated with Log(10) % amyloid, but urinary protein was not. There was a significant correlation between the area of amyloid deposition in renal tissue and parameters of renal function, especially Cr and Ccr. If amyloid deposition in renal tissue can be arrested or prevented, then it may be possible to maintain renal function at an acceptable level.

Association between clinical parameters and amyloid-positive area in gastroduodenal biopsy in reactive amyloidosis associated with rheumatoid arthritis

Our study was aimed to clarify an association between gastrointestinal (GI) amyloid-positive area and various kinds of factors including renal function in reactive amyloidosis associated with rheumatoid arthritis (RA). Twenty-five patients with an established diagnosis of reactive AA amyloidosis participated in the study between January 1989 and December 2009. Each patient satisfied the 1987 American Rheumatism Association criteria for RA. All patients showed amyloid deposits in both of GI and renal tissues. The average amyloid-deposited area was 2.2% in renal tissues and 3.7% in GI tissues although the difference was not statistically significant. Twenty-two patients out of 25 patients showed less than 5% of amyloidosis in renal tissues and nineteen patients showed 5% of amyloidosis in GI tissues. In 5 out of a total of 25 cases, the amyloid-deposited area in GI tissues was lesser than that in renal tissues. Mesangial proliferative glomerulonephritis, thin basement membrane disease (TBMD) and membranous nephropathy were frequently combined with renal amyloidosis. For statistical analyses, renal and GI tissues of % amyloid-positive areas were transformed to common logarithmic values (Log(10)%amyloid), since the histograms showed log-normal distribution. Clinical data were assessed by patient record at the time of GI biopsy. The correlation between Log(10)%GI-amyloid and age, creatinine (Cr), creatinine clearance (Ccr), blood urea nitrogen (BUN), and estimated glomerular filtration rate (eGFR) were not significantly associated with Log(10)%GI-amyloid in crude correlation analyses and also in sex- and age-adjusted linear regression analyses. Although GI biopsy was not correlated with clinical factors, GI amyloid-positive areas were larger than renal amyloid-positive areas. Endoscopic screening of the upper GI tract is common in Japan, and amyloid-deposited area in GI tissues was sufficient to use for the diagnosis of amyloidosis compared with renal tissues in terms of convenience and sensitivity.

Amyloid and the GI tract

Amyloidosis is characterized by the extracellular deposition of an abnormal fibrillar protein, which disrupts tissue structure and function. Amyloid may be localized to a single organ, such as the GI tract, or be systemic where the amyloid type is defined by the respective fibril precursor protein. Among patients with systemic amyloidosis, histological involvement of the gastrointestinal (GI) tract is very common but often subclinical. The presence and pattern of GI symptoms varies substantially, not only between the different amyloid types but also within them. GI presentations are frequently nonspecific and include macroglossia, dyspepsia, hemorrhage, a change in bowel habit and malabsorption. Endoscopic and radiological features of amyloidosis are also nonspecific, with the small intestine most commonly affected. In the absence of specific treatments for GI amyloidosis, therapy is aimed at reducing or eliminating the supply of the respective fibril precursor protein. Supportive measures such as nutritional support and antidiarrheal agents should be instigated while awaiting the clinical improvement associated with a successful reduction in the abundance of the fibril precursor protein. GI tract surgery should be performed only if the benefits clearly outweigh the risks, as there is a risk of decompensation of organs affected by amyloid.

A case with rheumatoid arthritis and systemic reactive AA amyloidosis showing rapid regression of amyloid deposition on gastroduodenal mucosa after a combined therapy of corticosteroid and etanercept

Systemic reactive amyloid A (AA) amyloidosis is one of the critical complications associated with rheumatoid arthritis (RA). Recently, there are several useful reports of anti-tumor necrosis factor therapy for RA-related systemic reactive AA amyloidosis patients. However, the time-kinetic transition between effective anti-inflammatory therapies and regression of AA amyloid deposits remains uncertain. Here, we report a RA patient with systemic reactive AA amyloidosis who was successfully treated with prednisolone and etanercept, showing marked regression of gastroduodenal mucosal amyloid deposits within only 4 months. This is the first case report of RA-related systemic reactive AA amyloidosis histopathologically demonstrating rapid regression of amyloid deposits on gastroduodenal mucosa after adequate suppression of the underlying inflammatory condition.

Effective Anti-TNF-α Therapy Can Induce Rapid Resolution and Sustained Decrease of Gastroduodenal Mucosal Amyloid Deposits in Reactive Amyloidosis Associated with Rheumatoid Arthritis

Objective.

To examine the effect of anti-tumor necrosis factor-α (anti-TNF) therapy in patients with reactive AA amyloidosis associated with rheumatoid arthritis (RA).

Methods.

Fourteen patients with reactive AA amyloidosis associated with RA were prospectively evaluated. Four patients were treated with infliximab and 10 with etanercept. The mean period of anti-TNF therapy was 20.1 ± 13.8 months. Laboratory findings and renal function were examined before and after initiation of anti-TNF therapy. In 9 patients the area of amyloid deposits in serial gastroduodenal mucosal biopsy specimens was examined and image analysis was performed.

Results.

C-reactive protein and serum amyloid A protein levels were significantly reduced after initiation of anti-TNF therapy. Twenty-four hour creatinine clearance improved in 4 patients, did not change in 5, and deteriorated in 3. Twenty-four hour urinary protein excretion was significantly decreased in 3 patients, not exacerbated in 6, and increased in 3 after initiation of anti-TNF therapy. The biopsy specimens from the 9 patients who underwent serial gastroduodenal biopsies showed significant decreases in the area of amyloid deposits, from 8.8% ± 6.4% to 1.6% ± 0.6% (p = 0.003) after initiation of anti-TNF therapy. Four patients showed a sustained decrease in the areas of amyloid deposits in their third biopsy specimens, and amyloid deposits were not detectable in 2.

Conclusion.

Our results indicate a striking effect of anti-TNF therapy for rapid removal and sustained disappearance of amyloid deposits in gastric mucosal tissue with amelioration of renal functions in patients with reactive amyloidosis due to RA.

Review article: gastrointestinal amyloidosis - clinical features, diagnosis and therapy

BACKGROUND

Amyloidosis is one of the unusual diseases about which a physician may not think when it is affecting the patient. During the last three decades, there has been an enormous progress in the understanding of the chemical nature, classification, pathogenesis, clinical features, diagnostic measures and therapy of this disorder.

AIM

To provide an updated review of amyloidosis affecting the gastrointestinal tract.

METHODS

Review of current medical literature.

RESULTS

Amyloid proteins (irrespective of the type) can deposit in various parts of the gastrointestinal tract and liver resulting in symptoms of abdominal pain, dysmotility, diarrhoea, gastrointestinal bleeding, hepatomegaly and even portal hypertension with its associated complications. Definitive diagnosis can only be made by histological examination of the affected organ. Disease modifying treatment with high-dose chemotherapy followed by autologous stem-cell transplantation has shown promise. Liver transplantation is an option for a select group of patients.

CONCLUSIONS

Suspicion of gastrointestinal amyloidosis in patients without known history of amyloidosis is difficult, but should be considered in those older than 30 years with unexplained diarrhoea, weight loss, autonomic dysfunction, malabsorption or proteinuria. While most gastrointestinal complications are managed symptomatically, causal therapy is reserved for a select few from various subtypes of this disorder.

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.

Development of ulcerative colitis during the course of rheumatoid arthritis: Association with selective IgA deficiency

A 56-year-old woman with a 29-year history of rheumatoid arthritis (RA) was admitted to the hospital, complaining of high fever, abdominal pain and severe bloody diarrhea. Colonoscopy revealed friable and edematous mucosa with spontaneous bleeding, diffuse erosions and ulcers extending from the rectum to the distal transverse colon. Histopathological findings of rectal biopsies were compatible with ulcerative colitis (UC). Being diagnosed as having severe active left-side UC, she was successfully treated with intravenous methylprednisolone followed by prednisolone and leukocytapheresis. Laboratory tests revealed low serum and saliva IgA levels, which might play a role in the development of UC. To our knowledge, this is the first case of UC occurring during the course of RA, accompanied by selective IgA deficiency.

Severe protein losing enteropathy with intractable diarrhea due to systemic AA amyloidosis, successfully treated with corticosteroid and octreotide

This report concerns two patients with severe protein losing enteropathy and refractory diarrhea due to AA amyloidosis who were successfully treated with corticosteroid and octreotide. In these patients, biopsied tissues from the gastrointestinal (GI) tract showed extensive deposition of AA amyloid, which was caused by rheumatoid arthritis in one case and was of unidentified etiology in the other. Both patients manifested severe diarrhea unresponsive to conventional treatment with hypoproteinemia, and protein leakage from the small intestine to the ascending colon was confirmed by 99mTc-diethylene triamine pentaacetic acid human serum albumin (HSA-D) scintigraphy. Soon after starting a long-acting somatostatin analogue, octreotide, with co-administration of oral prednisolone, their general status improved in parallel with a rapid decrease in the volume of watery diarrhea and an increase in serum levels of albumin and IgG. Also on 99mTc-HSA-D scintigraphy protein leakage from the GI tract was apparently decreased in both patients. Combination therapy with a somatostatin analogue and corticosteroid may be effective for protein losing enteropathy with intractable diarrhea ascribable to GI amyloidosis. Because of the lack of specific therapies in this serious clinical situation, the described therapy should actively be considered as a therapeutic option not only in AA amyloidosis, but also in other types of systemic amyloidosis.

Long-term outcome of renal transplantation in patients with familial Mediterranean fever amyloidosis: A single-center experience

Although recurrence of amyloid A deposition in the allograft can be seen in patients with secondary amyloidosis due to familial Mediterranean fever (FMF), renal transplantation remains to be a choice of treatment for end-stage renal disease. The aim of this study was to determine short- and long-term results of renal transplantation in patients with FMF amyloidosis. We compared the outcomes of 17 patients with FMF amyloidosis among 431 (3.9%) transplants with 209 control patients. We observed 93% and 94% graft and patient survivals at 1 year, and 89% and 90% at 5 years. Also, the mean serum creatinine levels at 1 and 5 years posttransplant were similar. Recurrence of amyloidosis was documented in two allograft recipients presenting with nephrotic range proteinuria (12%), one of whom lost the allograft due to recurrence. Eleven patients had FMF gene analysis. The results of MEFV mutation analyses were: M694V/M694V homozygote in six patients, M694V/EQ148 in one patient, M694V/V726A in one patient, 680M-I/E148Q in one patient. FMF gene analysis was negative in two patients. Recurrence was noticed in one patient with M694V/M694V, while the other did not have an FMF gene analysis. Colchicine was reduced in nine patients due to side effects. In conclusion, the long-term outcomes of transplantation in patients with amyloidosis secondary to FMF is similar to that in the general transplant population and maintenance colchicine, even at low dose, appears to effectively prevent recurrence of amyloidosis in the allograft.

Rapidly progressed secondary amyloidosis in a patient with mixed connective tissue disease

A 39-year-old woman with mixed connective tissue disease suddenly developed repeated watery diarrhea two years after the onset of the disease. A colonic biopsy specimen revealed amyloid A protein deposition and the diagnosis of secondary amyloidosis was established. The amyloid deposition disappeared after the 8-month course of the treatment with prednisolone and azathioprine. Molecular genetic analysis showed the presence of the gamma-allele in her serum amyloid A protein 1 gene. This might be associated with the early onset and progression of secondary amyloidosis in our case, just like cases reported in rheumatoid arthritis.

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.

Pathology of the temporomandibular joint of patients with rheumatoid arthritis--case reports of secondary amyloidosis and macrophage populations

INTRODUCTION

The pathogenetic features of rheumatoid arthritis of the temporomandibular joint (TMJ) are not well defined. In this paper the histological features of TMJs affected by rheumatoid arthritis, and the detection of secondary amyloidosis and macrophage populations in the TMJs of two patients with progressive rheumatoid arthritis are described.

METHODS

In two patients (64-year-old man and 61-year-old woman) with rheumatoid arthritis total TMJ replacement were performed. The surgical specimens were studied histologically.

RESULTS

It was found that the articular cartilage had been completely replaced by proliferating fibrous tissue. Congo red staining and polarizing microscopy revealed amyloid deposition in the connective tissue of the joint space. Immunohistochemical staining showed CD 68 positive macrophages around the amyloid deposition in the proliferating soft tissue.

CONCLUSION

TMJ involvement in rheumatoid arthritis followed the same destructive pathway as in other joints. Amyloid deposition and macrophage populations were detected in two TMJs affected by rheumatoid arthritis.

Relative serum amyloid A (SAA) values: the influence of SAA1 genotypes and corticosteroid treatment in Japanese patients with rheumatoid arthritis

OBJECTIVES

(1) To determine whether serum concentration of serum amyloid A (SAA) protein is influenced by the SAA1 allele in Japanese patients with rheumatoid arthritis (RA) as previously shown in a healthy control group; and (2) to analyse what factors, based on such an allelic bias, influence the relative SAA values of those patients.

METHODS

SAA and C reactive protein (CRP) concentrations together with SAA1 genotypes were determined in 316 Japanese patients with RA. The relative SAA values were evaluated as an SAA/CRP ratio.

RESULTS

Comparison of the three SAA1 homozygote groups showed that the SAA/CRP ratio was highest in the 1.5/1.5 group (mean 9.0, p<0.01 v the other two homozygote groups) followed by the 1.3/1.3 group (mean 7.2, NS v the 1.1/1.1 group) and the 1.1/1.1 group (mean 4.0). The SAA/CRP ratio was significantly higher in patients receiving corticosteroids regardless of the presence of allele 1.5. No clear differences in the ratio between patients with or without amyloidosis were found.

CONCLUSION

The SAA1.5 allele and corticosteroid treatment had a positive influence on SAA concentrations in serum. These findings are important when evaluating SAA concentration in inflammatory diseases and when considering the cause or treatment of amyloidosis.

Serum amyloid A (SAA): a concise review of biology, assay methods and clinical usefulness

Serum amyloid A (SAA) is a family of proteins encoded in a multigene complex. Acute phase isotypes SAA1 and SAA2 are synthesized in response to inflammatory cytokines. SAA and C-reactive protein (CRP) are now the most sensitive indicators for assessing inflammatory activity. In viral infection and kidney allograft rejection, SAA proved more useful than CRP. Development of convenient assay methods for SAA will facilitate its use in clinical laboratories.