A Behçet Case with Renal Amyloidosis

Abstract

Behçet's disease is a chronic systemic vasculitis with unknown etiology characterized by recurrent oral and genital ulcerations, ocular inflammation, having manifestations related to the skin and joints. Neurologic, pulmonary and gastrointestinal findings can also be observed during the course of the disease. In this report a case of Behçet's disease that had amyloidosis due to renal parenchymal involvement of the disease showing itself by nephrotic syndrome is presented.

• Behçet's disease
• Amyloidosis
• Nephrotic syndrome

Introduction

Hulusi Behçet first defined Behçet's disease in 1937 as a triad including recurrent oral and genital ulcerations and iridocyclitis. Later it was observed to be formed by larger symptom complexes. Therefore it is finally decided to be a vasculitis showing multisystem involvement.[[1]]

Renal involvement in Behçet disease is rare. Glomerulonephritis and amyloidosis development have also been reported as case reports in the literature.

Case Report

A 71 year-old male patient was diagnosed to be Behçet's disease, 10 years ago due to his recurrent oral afteous lesions, genital ulcerations, erythema nodosum and uveitis. An aneurysm was found in his right common femoral artery when he applied one year ago with ecchymosis and pain complaint in his right lower extremity and then a stent was applied. He was admitted to our hospital with complaints of dyspnea, edema at lower extremities, which had begun 3 months go.

Physical examination revealed pretibial edema and ascites. His blood pressure was 110/70 mm/Hg. Laboratory data revealed: white blood count: 6400/mm³, hematocrit: %39 platelets counts: 265.000/mm³, BUN: 23 (6–20) mg/dL, serum creatinine: 1.8 (0.6–1.3) mg/dL, albumin: 1.5 (3.4–5.0) g/dL, total protein: 4.6 (6.4–8.3) g/dL, cholesterol: 240 (140–220) mg/dL, LDL: 150 (50–130) mg/dL, sedimentation rate: 118 mm/h. The rest of the blood analyses were within normal range. Urinalysis revealed a specific gravity of 1019, pH 5.5, protein 500 mg/dL. A 24-h urine for creatine clearance and ESBACH were 62 mL/min and 8.7 g/day respectively. Abdominal ultrasonography demonstrated minimal free ascites in abdomen and renal size was observed to be normal. Although flow patterns of interlobar arteries in both kidneys were normal; RI was measured to be 0.72 and 0.70 in right and left kidneys respectively in renal Doppler ultrasonography, in concordance with renal parenchymal disease.

Renal biopsy was performed to this patient who had proteinuria in nephrotic levels. Widespread glomerular deposition of moderately eosinophilic homogenous material was observed in a section of renal biopsy stained with routine HE. Two sections of the kidney tissue stained with crystal violet and Congo red revealed positive results for amyloid deposits in the glomeruli and vessels (Figs. 12). In the Congo red stained sections yellow green birefringence of the deposits by polarizing microscope was observed. Immunohistochemically, there was positive reactivity with AA amyloid antibody in glomerular amyloid deposits (Fig. 2—inset).

Figure 1. Positive results for amyloid deposits in the glomeruli and the wall of a blood vessel (×150).

Figure 2. Deposits of amyloid in the glomeruli and vessels (×150). Inset shows immunohistochemically positive AA amyloid reactivity in a glomerulus (×300).

Discussion

In an article published in 1975, Chajek and Fainaru stated that “B.D. does not affect the kidney.” Their statement was based on an evaluation of the clinical findings reported in 683 published cases.[[2]] Many comprehensive review articles about BD do not include renal involvement among the organs affected. At times, renal involvement has been cited in letters to the editor. Despite this lack of recognition and importance, several renal problems have been associated with BD and can be divided into 5 groups: (1) glomerulonephritis, (2) amyloidosis, (3) renal vascular involvement, (4) interstitial nephritis and (5) other problems, such as complications of drug therapy or genitourinary system abnormality.[[3]] Most articles describing the renal complications of BD are presented as case reports.

The frequency of amyloidosis among BD patients varies between 0.01 and 4.8% in different series. Filali-Ansary reported 162 cases of BD between 1983 and 1996 but they found amyloidosis in only one case.[[4]] Also in one study concerning 120 BD patients, 9 patients were found to have renal involvement and only one of them had proteinuria in nephrotic levels due to amyloidosis.[[5]] The interval between the onset of the first symptom of BD and the diagnosis of amyloidosis ranges from 1 to 27 years in the literature.[[6]] In our case this interval was 10 years. Patients with systemic amyloidosis secondary or reactive to chronic infections or inflammatory disorders and certain tumors have as the major protein constituent in their amyloid fibrils as AA. We also found amyloid AA fibrils in immunohistochemical studies of our patient. In one study-investigating prognosis in BD patients with amyloidosis; it was reported that end-stage renal disease develops in a short time with a high mortality ratio in these patients, so amyloidosis development in BD is a poor prognostic criteria. For this reason; renal functions and urine samples should be monitored in patients with BD.

As a result we presented this case because nephrotic syndrome due to amyloidosis in BD is rare.