Vasculitis

Systemic lupus erythematosus (SLE) is a multi-systemic disease of the connective tissue characterized by the presence of numerous antibodies, circulating immune complexes, and deposition of immune complexes in multiple organ systems. (1) In addition, a disturbance in the regulation of immunoglobulins occurs, with a defect in suppressor T lymphocytes associated with polyclonal activation of B lymphocytes and the uncontrolled production of autoantibodies and immune complexes. (2)

Gastrointestinal vasculitis in SLE is rare and almost always is associated with evidence of active disease in other organs. (3) Computed tomography (CT) of the abdomen in patients with SLE who have abdominal vasculitis shows ascites and thickening of the bowel walls, with a double-halo or target sign. (4,5) Ascertaining whether abdominal pain is due to SLE or is a surgical problem is difficult in patients with SLE. (6)

We report a case of a patient with a relapse of SLE who had abdominal signs and symptoms mimicking those of an acute abdomen and bizarre-looking findings on angiograms of the superior mesenteric vessels.

Clinical Findings

A 48-year-old African American woman who had had SLE for 11 years was admitted to the medical intensive care unit because she had had cough, fever, sore throat, headaches, nasal congestion, nausea, and vomiting for 3 weeks. Her last exacerbation of SLE had been 10 years ago, and she had been in remission since then. She had a history of hypertension, tuberculosis (for which she had received a triple-drug therapy for 1 year), and chronic renal insufficiency. She had undergone a right hip replacement because of avascular necrosis of the femoral head associated with use of corticosteroids.

Her initial blood pressure in the emergency room was 70 mm Hg/palpable. She was tachycardic with a heart rate of 122/min, but the heart rate improved with the administration of crystalloid solution and corticosteroids. She was febrile (temperature, 38.9[degree]C). Chest examination revealed stony dullness to percussion in the lower zones of both lungs and reduced air entry bilaterally on auscultation. Chest radiographs showed bilateral pleural effusion and bilateral pulmonary congestion or infiltrates. Heart sounds were normal with no murmur and no pericardial friction rub. The abdomen was flat, soft, and nontender and moved with respiration. Bowel sounds were active. Lower extremities had bilateral pitting pedal edema. Her medications included clonidine, enalapril, amlodipine, ceftriaxone, azithromycin, metronidazole, intravenous labetolol, furosemide, methylprednisolone, and calcium acetate.

Four days after admission, she had severe generalized coliclike abdominal pain, with a feeling of wanting to pass flatus. The abdomen was distended and tender but was soft, without guarding or rebound tenderness. She had hypoactive bowel sounds. Findings on rectal examination were normal, with guaiac-negative stools. No indication of pneumoperitoneum was evident on an abdominal radiograph. A CT scan of the abdomen showed mucosal thickening and edema of the bowel wall, with concentric halos and the appearance of a target sign (Figure 1). In addition, a large ascites and bilateral pleural effusions were evident. The liver, spleen, kidneys, and pancreas all looked normal, and no evidence of intestinal obstruction or perforation was detected. The diagnosis of bowel vasculitis was considered.

[FIGURE 1 OMITTED]

Superior mesenteric angiograms obtained the same day showed shunting of contrast material from the mesenteric arterioles directly to the venous system, to the mesenteric vein and further to the portal venous system, almost completely bypassing the capillary system (Figure 2). The patient's abdominal signs and symptoms subsided during the next 3 days after treatment with high-dose intravenous methylprednisolone. After the resolution of the abdominal pain and other acute signs and symptoms of SLE, she was transferred from the medical intensive care unit to the in-patient ward to fully recover from the relapse.

[FIGURE 2 OMITTED]

Discussion

SLE is a multiorgan autoimmune inflammatory disease marked by the presence of antinuclear antibodies and the deposition of antigen-antibody complexes and complement along vascular basement membranes. Although both sexes and all ethnic and racial groups can be affected, the disease occurs more often in women of child-bearing age and in African Americans. (7) Multiple systems may be affected, most commonly the joints, kidneys, central nervous system, and serosal surfaces. The inflammation of serosal surfaces may be associated with chronic pleuritis, pericarditis, or peritonitis. (8)

Vasculitis of postcapillary venules with accumulation of neutrophils or lymphocytes occurs in 20% of patients. (1) The blood vessels typically have a fibrinoid necrosis, thrombosis, and a variable cellular infiltrate. These patients have a low concentration of serum complement and high serum levels of immune complexes and may have antiphospholipid antibodies.

Involvement of the gastrointestinal tract in SLE is not often considered because many gastrointestinal signs and symptoms can be attributed to complications of drug therapy, such as treatment with salicylates, nonsteroidal anti-inflammatory drugs, steroids, and azathioprine. Gastrointestinal manifestations of SLE include anorexia, nausea, mild pain, diarrhea, ascites, nonnecrotizing pancreatitis, abnormal values on liver function tests, and lupus peritonitis. Lupus peritonitis may mimic an acute surgical abdomen requiring surgical intervention. (6)

Involvement of the gastrointestinal tract in SLE is quite rare and is almost always accompanied by evidence of active disease in other organs, although occasionally it may be the main clinical feature of the disease. In a study by Drenkard et al, (9) only 1 of 540 patients with SLE had mesenteric vasculitis. In patients with lupus mesenteric vasculitis, findings on CT scans obtained within 1 to 4 days of the onset of severe abdominal pain and tenderness include prominent mesenteric vessels with a palisade pattern or comb-like appearance that supply focal or diffuse dilated bowel loops; ascites with increased peritoneal enhancement; and thickening of the small bowel, with a double-halo or target sign. The CT findings are reversed after prompt administration of high-dose steroids. (4,5)

Of interest, the CT findings in our patient fit this description. More noteworthy is that the superior mesenteric angiograms showed shunting of blood from the arterioles to the venous channels, bypassing the capillaries. A possible explanation of this phenomenon could be the occlusion of the postcapillary venules by deposition of immune complexes. Evidence of the involvement of immune complexes in this case was the low levels of the C3 (0.63 g/L) and C4 (0.13 g/L) components of complement associated with the consumption of complement in the inflammatory process and the high normal concentrations of immunoglobulin G (11.2 g/L) and immunoglobulin M (0.62 g/L) (see Table). This distal obstruction could lead to the opening of the precapillary sphincters, which are closed under normal circumstances, to shunt blood from the arterial end to the venous end, thereby bypassing the capillaries.

The mesenteric capillary bed has a central channel in sequence with the metarteriole, which anastomoses with a venule. Capillaries continue from and also take off from the precapillary vessels as direct branches. The central thoroughfare channels maintain a constant-pressure relationship between their arteriolar and venular ends. The changes in the caliber of the arteriolar-venular anastomosis are related to the activity of the capillary circulation. When most capillary vessels are open and have active blood flow, the arteriolar-venular anastomoses remain closed; they open when capillary circulation decreases. These shunts may be preferentially in use when vasoconstriction of small arteries beyond the shunts increases resistance to flow. (10)

* In this case, shunting of blood from arteriole to venous channels, bypassing bowel capillaries, was noted on the superior mesenteris angiogram and was most likely due to occlusion of the postcapillary venule by immune complexes.

* The patient responded well to high-dose intravenous steroid therapy.

* The diagnosis of gastrointestinal vasculitis in systemic lupus erythematosus (SLE) is rare and often not considered because of the frequency of gastrointestinal symptoms related to SLE therapies.

REFERENCES

(1.) Nuki G. Disease of the connective tissue joints and bones. In: Edwards CRW, Bouchier IAD, Haslett C, Chilvers ER, eds. Davidson's Principles and Practice of Medicine. 17th ed. New York, NY: Churchill Livingstone; 1995:912-915.

(2.) Shur PH. Systemic lupus erythematosus. In: Goldman L, Bennett JC, eds. Cecil Textbook of Medicine. 21st ed. Philadelphia, Pa: WB Saunders Co; 2000:1509-1517.

(3.) Grimbacher B, Huber M, von Kempis J, et al. Successful treatment of gastrointestinal vasculitis due to systemic lupus erythematosus with intravenous pulse cyclophosphamide: a clinical case report and review of literature. Br J Rheumatol. 1998;37:1023-1028.

(4.) Tsushima Y, Uozumi Y, Yano S. Reversible thickening of the bowel and urinary bladder wall in systemic lupus erythematosus: a case report. Radiat Med. 1996;14:95-97.

(5.) Ko SF, Lee TY, Cheng TT, et al. CT findings at lupus mesenteric vasculitis. Acta Radiol. 1997;38:115-120.

(6.) Wakiyama S, Yoshimura K, Shimada M, Sugimachi K. Lupus peritonitis mimicking acute surgical abdomen in a patient with systemic lupus erythematosus: report of a case. Surg Today. 1996;26:715-718.

(7.) Hahn BH. Systemic lupus erythematosus. In: Fauci AS, Braunwald E, Isselbacher K J, et al, eds. Harrison's Principles of Internal Medicine. 14th ed. New York, NY: McGraw-Hill; 1998:1874-1880.

(8.) Klippel JH. Systemic lupus erythematosus. In: Stein JH, Klippel JH, Reynolds HY, et al, eds. Internal Medicine. 5th ed. St Louis, Mo: Mosby; 1998:1212-1218.

(9.) Drenkard C, Villa AR, Reyes E, Abello M, Alarcon-Segovia D. Vasculitis in systemic lupus erythematosus. Lupus. 1997;6:235-242.

(10.) Zweifach BW. General principles governing the behavior of the microcirculation. Am J Med. 1957;23:684-696.

Asuquo N. Inyang, MD, FRCS, FWACS, AFMCS, and Harry Ulrrich, MD. From Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY.

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