Mesenteric Lymphadenopathy From Recurrent Giardiasis: A Rare Cause of Small Bowel Obstruction in a Patient With X Linked Agammaglobulinemia

Introduction: Giardiasis, the most common parasitic infection of the human intestine, is caused by the binucleated protozoan parasite Giardia duodenalis (G intestinalis, giardia lamblia). This infection is commonly reported in developing countries; however, it remains one of the most common parasitic infections in the United States. This infection is also often found in populations with immunodeficiency disorders, such as X Linked agammaglobulinemia. Here, we discuss the case of a patient with X linked agammaglobulinemia who presented with a rare complication of small bowel obstruction (SBO) due to recurrent giardiasis. Case Description/Methods: A 59-year-old male with medical history of X linked agammaglobulinemia, bronchiectasis, COPD, iron deficiency anemia, intestinal malabsorption presented with the complaints of abdominal discomfort and intractable vomiting. The patient also reported similar complaints in the past. Review of systems unremarkable. Initial lab tests revealed leukocytosis (WBC 14.5 K/micro-L), Na 133 mmol/L, K 4.0 mmol/L, BUN 17 mg/dl, Cr 1.17 mg/dl, LFT with in normal limits. X Ray abdomen suggestive of ileus rather than small bowel obstruction. Stool studies positive for calprotectin and lactoferrin. EGD showed giardiasis, colonoscopy biopsies negative for IBD and cancer. CT Abd is unremarkable except for persistent prox. Jejunal luminal narrowing. MR Enterography positive for mesenteric lymphadenopathy causing persistent small bowel obstruction (Fig 1). Discussion: X linked agammaglobulinemia is an inherited immunodeficiency disorder characterized by a failure to produce mature B lymphocytes and antibodies. Because of the lack of antibodies, patients most often present with recurrent upper respiratory tract infections, followed by gastrointestinal infections. Patients with giardiasis present with chronic diarrhea, bloating, nausea and vomiting. Functional dyspepsia, irritable bowel syndrome and cancer are additional intestinal manifestations of giardiasis. The pathophysiology is thought to be due increased enterocyte apoptosis, intestinal barrier dysfunction, malabsorption and increased intestinal transit rates caused by the host’s pathogen immune response. SBO from giardiasis is very rarely reported and has been hypothesized to relate to altered intestinal motility. More research is needed to study the details of the mechanism causing this complication.Figure 1.: Massively distended small bowel loops (shown by orange arrow).