Early Intervention and Resolution of Pediatric Intestinal Pseudo-Obstruction in Systemic Lupus Erythematosus: A Pediatric Case Report

**Background:** Pediatric intestinal pseudo-obstruction (PIPO) is a rare, severe dysmotility disorder that mimics mechanical bowel obstruction without an anatomic blockage. It can result from damage to the enteric nervous system, smooth muscle, or interstitial cells of Cajal. Chronic intestinal pseudo-obstruction (CIPO) is an under-recognized manifestation of systemic lupus erythematosus (SLE) in adults, but pediatric incidence is unknown. Early identification and intervention may improve prognosis, but the window to treat early dysmotility and prevent PIPO has not been reported. This case presents a 7-year-old girl with PIPO as the initial presentation of SLE, who showed dramatic recovery with plasmapheresis, rituximab, and cyclophosphamide, representing the youngest reported case of dysmotility secondary to SLE.

**Methods:** This is a single case report of a 7-year-old Pacific Islander female who presented with abdominal pain, fatigue, constipation, ageusia, anorexia, and nonbloody, nonbilious emesis over weeks, preceded by intermittent low-grade fevers and sore throat. Physical exam showed hypoactive bowel sounds and hepatomegaly without distension, ascites, or splenomegaly. She lost 8 kg (weight z-score dropped from 1.07 to -2.27). Laboratory findings included elevated transaminases (AST 29–108 U/L, ALT 39–220 U/L), hypoalbuminemia (3.4 g/dL), normocytic anemia (Hb 10.6 g/dL), leukopenia (2.8 K/μL), lymphopenia (1300/mm³), elevated ESR (14–27 mm/hr), and IgG (1430 mg/dL). SLE was diagnosed based on positive ANA (>1:2560), anti-Smith (92 U/mL), anti-RNP (>100 U/mL), hypocomplementemia (C3 71 mg/dL, C4 10 mg/dL), hematologic abnormalities, pericardial effusion, positive anticardiolipin antibodies (33 IgG PL U), antineuronal cell antibody (>400 U), and elevated rheumatoid factor (>100 IU/mL). Anti-dsDNA and paraneoplastic markers were negative. Imaging (abdominal ultrasound, elastography, chest CT, abdominal radiographs, MRI with angiography) showed no mechanical obstruction but large stool burden and gas paucity. Upper endoscopy showed scant antral erythema, H. pylori negative. She developed intractable bilious emesis and ileus, becoming dependent on parenteral nutrition (PN). PIPO secondary to SLE was suspected. Initial treatment included pulse methylprednisolone 30 mg/kg/d for 3 days, then maintenance 1 mg/kg/d twice daily, plus erythromycin and amoxicillin/clavulanic acid as promotility agents, but intestinal failure progressed. Due to refractory symptoms, she received rituximab 500 mg/m² on day 25 and therapeutic plasma exchange (TPE) on day 26. She developed bowel sounds 1 day after TPE and had a bowel movement 2 days later (first in 16 days). She received a total of 7 TPE sessions, 2 doses of rituximab for induction, followed by 6 months of monthly intravenous cyclophosphamide 500 mg/m². Enteral feeds were initiated, PN weaned, and she was discharged on oral feeding. As an outpatient, she weaned off corticosteroids and is on mycophenolate mofetil maintenance, maintaining adequate growth on oral feeding.

**Key Results:** The patient showed rapid clinical improvement after TPE and rituximab, with return of bowel function (bowel sounds 1 day after TPE, bowel movement 2 days later after 16 days of no bowel movements). She was successfully weaned from PN and discharged on oral feeding. At follow-up, she maintained adequate growth on oral feeding and weaned off corticosteroids. The combination of TPE, rituximab, and cyclophosphamide has not been previously described in SLE-associated dysmotility. The authors hypothesize that SLE led to antibody-mediated PIPO, explaining the poor response to corticosteroids alone and dramatic improvement with TPE.

**Clinical Implications:** This is the first report demonstrating prevention of chronic intestinal failure in a child with PIPO caused by SLE using TPE and immunosuppression. The case emphasizes that evaluation of acute PIPO should include workup for SLE, and therapy directed against clearance of pathogenic antibodies and antibody-mediated tissue injury (e.g., TPE, rituximab, cyclophosphamide) should be considered if steroids fail. Early recognition and aggressive treatment can rapidly reverse acute intestinal failure and prevent lifelong PN dependence. Limitations include the single-case design and inability to complete motility studies, but the dramatic response suggests a potential therapeutic approach for this rare condition.