EXTENDED REPORT

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

T M El Mansoury¹, B P C Hazenberg², S A El Badawy³, A H Ahmed¹, J Bijzet², P C Limburg², M H van Rijswijk²

¹ Department of Rheumatology and Rehabilitation, University Hospital of El Minia, Egypt
² Division of Rheumatology, Department of Medicine, University Hospital, Groningen, The Netherlands
³ Department of Rheumatology and Rehabilitation, University Hospital of Cairo, Egypt

Correspondence to:
Correspondence to:
Dr B P C Hazenberg, Division of Rheumatology, Department of Medicine, University Hospital, PO Box 30.001, 9700 RB Groningen, The Netherlands;
b.p.c.hazenberg{at}int.azg.nl

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.

Keywords: amyloid protein AA; adipose tissue; Congo red; rheumatoid arthritis

Abbreviations: ELISA, enzyme linked immunosorbent assay; ESR, erythrocyte sedimentation rate; HAQ, Health Assessment Questionnaire; JCA, juvenile chronic arthritis; RA, rheumatoid arthritis; RBC, red blood cells; RF, rheumatoid factor; SAA, serum amyloid A

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

• KURODA, T., WADA, Y., KOBAYASHI, D., MURAKAMI, S., SAKAI, T., HIROSE, S., TANABE, N., SAEKI, T., NAKANO, M., NARITA, I. (2009). Effective Anti-TNF-{alpha} Therapy Can Induce Rapid Resolution and Sustained Decrease of Gastroduodenal Mucosal Amyloid Deposits in Reactive Amyloidosis Associated with Rheumatoid Arthritis. The Journal of Rheumatology 36: 2409-2415 [Abstract] [Full Text]  
• Nakamura, T., Higashi, S., Tomoda, K., Tsukano, M., Baba, S., Shono, M. (2006). Significance of SAA1.3 allele genotype in Japanese patients with amyloidosis secondary to rheumatoid arthritis. Rheumatology (Oxford) 45: 43-49 [Abstract] [Full Text]  
• Maksymowych, W. P. (2003). Mandatory pharmacovigilance. CMAJ 168: 672-672 [Full Text]