Case Report: A Lupus Patient with Abdominal Pain

Key: NSAIDs: non-steroidal anti-inflammatory drugs; MMF: mycophenolate mofetil; HCQ: hydroxychloroquine.

Table 2: Anatomic Distribution of GI Involvement among Patients with SLE²

Lupus Enteritis

According to the BILAG 2004 definition, lupus enteritis is either vasculitis or inflammation of the small bowel with supportive imaging and/or biopsy findings.⁴ It may also be called mesenteric arteritis, intestinal vasculitis, enteric vasculitis, mesenteric vasculitis, lupus peritonitis or abdominal serositis. 

Figure 4: Proposed Treatment Algorithm for SLE Patients with Lupus Enteritis³

Although the pathogenesis of lupus enteritis remains unknown, it has been reported that immune complex-mediated visceral vasculitis may result in bowel wall and mucosal edema.⁵ The most common clinical manifestations include abdominal pain, ascites, nausea, vomiting, diarrhea and fever (see Figure 3,).³

Lab findings in lupus enteritis include anemia (52%), leukocytopenia and/or lymphocytopenia (40%), thrombocytopenia (21%) and hypocomplementemia (88%).³ 

A retrospective study by Koo et al. found C4 was significantly lower in patients with lupus enteritis.¹ 

A retrospective study and systematic literature review by Janssens et al. found the following lab abnormalities in patients with lupus enteritis: ANA (92%), anti-dsDNA (74%), anti-RNP (28%), anti-SSA (26%) and anti-Sm (24%) antibodies, proteinuria >0.5 g/24h (47%), positive antiphospholipid antibodies (30%). Seven patients in this study met criteria for antiphospholipid antibody syndrome.³ 

In the same review, the authors found the most common radiographic findings were bowel wall edema (91%); double halo or target sign (71%); dilation of bowel lumen (24%); ascites (78%); mesenteric abnormal­ities (71%), including engorgement of mesenteric vessels; and increased number of viable vessels (comb sign).³ 

Table 3  shows the frequency of CT findings in SLE patients with undiffer­entiated acute abdominal pain.⁶ The jejunum and ileum are more frequently involved, followed by the colon, duodenum and rectum. Of the cases identified in this review, 15% had endoscopy with normal macroscopic findings in 60%.³ Endoscopic biopsy is of low yield. Therefore, lupus enteritis is generally a diagnosis of exclusion. 

Table 3: CT Findings of SLE Patients with Undifferentiated Acute Abdominal Pain⁶

Treatment

Corticosteroids are the initial treatment for all patients, with an average duration of four days (range 1–34 days).³ Cyclo­phosphamide can be considered, especially if there is other severe organ involvement (see Figure 4). Maintenance therapy typically includes hydroxychloroquine, mycophenolate mofetil or azathioprine.  Most patients have relief of symptoms in less than one week, and recurrence occurs in 23% of patients.³