Background

IgA vasculitis, formerly known as Henoch-Schönlein purpura, is characterised by the deposition of IgA-immune complexes within small-vessel walls.1 This disease can develop at any age, but it commonly affects children.2 3 IgA vasculitis is the most common systemic vasculitis in childhood, with an annual incidence of 3–26 per 100 000 children.4 5 In contrast, adult IgA vasculitis is extremely rare, with an annual incidence of 0.1–14 per 100 000 individuals.6 IgA vasculitis affects multiple organs, including the skin, joints, gastrointestinal (GI) tract and kidneys.7 Reflecting a wide variety of affected organs, patients with IgA vasculitis show various clinical symptoms such as fever, purpura, arthralgia, abdominal pain and haematuria. Purpura is observed in almost all paediatric patients8 and is reportedly the initial symptom of IgA vasculitis in approximately three-quarters of affected children.9 Thus, typically, patients with IgA vasculitis initially present with purpura, followed by the development of arthralgia, haematuria and GI-related symptoms within the following few days. Both typical clinical signs and histopathological detection of leucocytoclastic vasculitis associated with IgA deposition are used to establish the diagnosis of IgA vasculitis.1 Glucocorticoids ameliorate GI-related symptoms, arthralgia and purpura in most patients with IgA vasculitis.

Diagnosing IgA vasculitis is easy when paediatric patients exhibit characteristic purpura and joint-related, GI-related and renal symptoms. However, clinicians may need to consider a possibility of IgA vasculitis, even in the absence of purpura, if any of these symptoms are present. A lack of skin involvement may make it difficult to diagnose this disease. Considering that the delayed diagnosis of IgA vasculitis may sometimes lead to serious complications such as intestinal obstruction, intussusception, intestinal perforation and massive bleeding, a prompt diagnosis is necessary.6 Here, we report a case of an adult patient with IgA vasculitis of the small bowel, without concurrent skin involvement. Interestingly, this patient also developed cytomegalovirus (CMV) enteritis after receiving glucocorticoid therapy. To the best of our knowledge, this is the first reported case of purpura-free, small intestinal IgA vasculitis, complicated by CMV reactivation, in an adult.

Case presentation

A 68-year-old man, with no significant prior medical history, was admitted to our hospital after presenting with a 3-day history of abdominal pain, vomiting, diarrhoea and high fever (38.7°C). The bouts of vomiting and diarrhoea occurred several times a day. Physical abdominal examination revealed severe distention and tenderness.

Investigations

Laboratory findings revealed an elevated C-reactive protein level, along with leucocytosis (table 1). Biochemical tests revealed elevated levels of serum transaminases (aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase and creatine kinase). Abdominal CT showed thickening of the descending duodenal and jejunal walls, a finding that was consistent with the diagnosis of infectious gastroenteritis. Based on these data, we initially suspected infectious enteritis, and the patient was treated with antibiotics. However, he did not respond to bowel rest and antibiotic treatment. Thus, we considered the possibility of other diseases such as vasculitis, malignant lymphoma and malignant tumour since stool and blood cultures were negative for pathogenic microorganisms. To explore this possibility, we measured the serum concentrations of interleukin 2 receptor, carcinoembryonic antigen, carbohydrate antigen 19–9 and factor XIII activity levels. The soluble interleukin 2 receptor level was also elevated (1988 U/mL, normal range: 121–613 U/mL), whereas those of tumour markers were within the normal range. Serum factor XIII activity decreased to 37%. Contrast-enhanced abdominal CT imaging after antibiotic treatment revealed marked thickening of the small bowel wall originating from the duodenum to the proximal portion of the jejunum (figure 1A). Persistent high fever and abdominal pain, despite administration the antibiotic treatment, prompted us to examine the mucosa of the upper GI tract, including the jejunum, by balloon enteroscopy on the 11th day of hospitalisation. Mucosal oedema, redness, erosion and transverse ulcers were observed from the descending portion of the duodenum to the proximal jejunum (figure 1B). Jejunal biopsy specimens obtained during the first single-balloon enteroscopy (SBE) procedure revealed destruction of the crypt architecture, massive infiltration of immune cells and mucosal haemorrhage (figure 2A). Moreover, IgA deposition in the capillary vessel walls and IgA-expressing plasma cells were visualised in the immunohistochemical analysis (figure 2B). IgA expression not only in the lamina propria immune cells but also in the capillary vessel walls (figure 2C) led us to consider the possibility of enteric IgA vasculitis as IgA deposition in capillary walls is a specific finding of this immune disorder.10 A significant decrease in serum factor XIII activity was also consistent with IgA vasculitis. Thus, this patient was diagnosed with solitary enteric IgA vasculitis and then treated with prednisolone (PSL). PCR using jejunal biopsy samples did not detect tuberculosis. A second SBE was performed 2 weeks after initiation of PSL treatment to re-examine the small intestinal mucosa. Persistent mucosal oedema, erosions and transverse ulcers were still present within the GI tract, extending from the descending duodenum to the proximal jejunum. In addition, large shallow ulcers had appeared in the jejunum (figure 3A). Histopathological examination of the jejunal biopsy specimens, obtained during the second SBE, showed massive infiltration of immune cells, IgA deposition within the capillary walls and accumulation of IgA-expressing plasma cells (figure 3B). In addition to these pathological findings, giant cells with inclusion bodies as well as CMV-positive cells, characteristic of IgA vasculitis, were also found in the jejunal biopsy specimens (figure 3C). We also detected blood leucocytes expressing CMV pp65 antigen (5/50 000; normal, 0). The response to PSL during the first 7 days was quite effective, similar to the response in most cases of IgA vasculitis; subsequently, the effect was lost. Such alterations in responses to PSL can be explained by the occurrence of CMV reactivation after PSL treatment. Thus, it is likely that CMV enteritis developed owing to immunosuppression by PSL. Simultaneous occurrence of IgA vasculitis and CMV enteritis was less likely, as the CMV immunostaining test performed on the first jejunum biopsy specimen had a negative result. These findings strongly suggest that CMV reactivation had occurred after administration of high-dose PSL and that the abdominal symptoms had persisted owing to the development of CMV enteritis.

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Figure 1

Endoscopic findings of the jejunal mucosa during single-balloon enteroscopy (SBE): (A) contrast-enhanced abdominal CT shows marked thickening of the descending duodenal (left) and proximal jejunal (right) walls. (B) SBE shows oedema, redness, erosions and transverse ulcers involving the duodenal (left) and jejunal (right) mucosae.

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Figure 2

IgA deposition within the jejunal mucosal capillary walls: (A) histopathological examination of the jejunal mucosa shows destruction of crypt architecture, massive infiltration by immune cells and mucosal haemorrhage (H&E, 40× magnification); (B) immunohistochemical examination of a jejunal biopsy sample shows deposition of IgA within the capillary walls along with aggregated IgA-expressing plasma cells (IgA immunostaining, 40× magnification); (C) high-magnification image of immunohistochemical staining shows IgA deposition in the capillary vessel walls (yellow arrow) (IgA immunostaining, 80× magnification).

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Figure 3

Jejunal mucosal findings indicating cytomegalovirus (CMV) reactivation: (A) single-balloon enteroscopy (SBE) shows mucosal oedema, redness, erosions and transverse ulcers involving the jejunal mucosa (left). Image taken after staining the jejunal mucosa with indigo carmine (right). (B) Jejunal biopsy samples obtained during the follow-up SBE show massive infiltration of immune cells within the jejunal mucosa (left) (H&E, 40× magnification) along with deposition of IgA in the capillary walls and high-magnification image of immunohistochemical staining shows accumulation of IgA-expressing plasma cells and IgA deposition in the capillary vessel walls (yellow arrow) (IgA immunostaining, 80× magnification) (right). (C) Histopathological examination of jejunal biopsy samples obtained during the follow-up SBE shows a giant cell with inclusion bodies (yellow arrow) (left) (H&E, 40× magnification) and positive immunoreactivity for CMV (right) (anti-CMV monoclonal immunostaining, 40× magnification).

Differential diagnosis

Considering the initial clinical presentation and investigation, the patient had been briefly considered to have infectious gastroenteritis, IgA vasculitis, eosinophilic gastroenteritis or CMV enteritis.

Treatment

The patient was initially treated with fluid replacement and antibiotics for suspected infectious gastroenteritis. After the histopathological diagnosis of IgA vasculitis following the first SBE, PSL (60 mg/kg) therapy was initiated. Ganciclovir (5 mg/kg two times per day) was added to the PSL treatment according to the findings of the subsequent (second) jejunal biopsy, which confirmed the occurrence of CMV enteritis. This led to symptom relief, and PSL was gradually tapered to a dose of 30 mg/day by discharge.

Outcome and follow-up

A marked improvement in abdominal symptoms was observed after initiation of ganciclovir. Blood leucocytes expressing CMV pp65 were no longer detected 2 weeks after initiation of antiviral therapy. The patient was discharged on the 53rd day of hospitalisation.