Protein-losing enteropathy associated with or without systemic autoimmune disease: what are the differences?

Objective: The aim of our study was to compare protein-losing enteropathy (PLE) associated with or without systemic autoimmune (SA) diseases.

Methods: Patients diagnosed with PLE were selected, and their clinical characteristics, laboratory, endoscopic and imaging characteristics, treatment, and outcome were analyzed.

Results: From 2001 to 2010, 74 patients (60 patients with SA disease) with a female predominance were diagnosed with PLE. The SA group tended to be younger, presented early (4.3 vs. 7 weeks, P=0.08), and had significantly more mucocutaneous-articular involvement (16.7 vs. 0%, P<0.05; 50 vs. 0%, P<0.02; 43.3 vs. 0%, P<0.01), compared with the other group, which showed more weight loss (64.3 vs. 25%, P<0.01), malaise and fatigue (57.1 vs. 28.3%, P<0.02), and tended to have more gastrointestinal (GI) symptoms. The SA group was associated with lymphopenia (0.8 vs. 2.7 × 10⁹/l, P<0.01), hyperglobulinemia (43 vs. 31.2 IU/l, P<0.04), lactate dehydrogenase (511.1 vs. 393.5 IU/l, P<0.05), hematuria (48.3 vs. 7.1%, P<0.01), and pyuria (23.3 vs. 0%, P<0.03), whereas the non-SA group had a higher platelet count (402 vs. 262.5 × 10⁹/l, P<0.01) and alkaline phosphatase (111 vs. 78.2 IU/l, P<0.03) on admission. A subgroup analysis of patients with SA disease showed that more lupus patients had pericardial effusion (14.6 vs. 0%, P=0.08), polyarthritis (50 vs. 16.7%, P=0.02), lower C3 level (0.5 vs. 0.85 mg/l, P<0.01), antinuclear factors (89.6 vs. 58.3%, P<0.01), and antiextractable nuclear antigen antibody (73.3 vs. 37.5%, P<0.03), whereas nonlupus patients had higher C-reactive protein (87.9 vs. 40 mg/l, P<0.01) and more antineutrophil cytoplasmic antibody (ANCA) (60 vs. 3%, P=0.00). Thirty-seven (71%) patients with SA disease had diffuse nonerosive erythematous GI mucosa with chronic inflammatory cells in the lamina propria layer, and 12 (85.7%) patients without SA disease had focal lesions. The treatment response was comparable between the two groups. However, the time required to normalize the serum albumin level (6.3 vs. 12.3 months, P=0.02) of patients with SA disease was much shorter than that of the non-SA group and those of inflammatory markers, specifically, C-reactive protein and complement C3, of its own group (6.3 vs. 11.6 vs. 12.1 months, P<0.04). More patients without SA disease had infective episodes during the management period (14.3 vs. 1.7%, P<0.01).

Conclusion: Patients with PLE associated with SA disease tend to have a distinct clinical syndrome with regard to the extent of clinical manifestations and laboratory, endoscopic, and histological features compared with those without. Patients without SA disease are more prone to develop complications and mortality. However, both can be effectively treated with comparable treatment response.