Patient description: A 34 year old man comes to the clinic complaining of dizziness and severe diarrhea since yesterday. He has returned from an international trip few days ago and was living in a camp in Sudan for a month. He developed abdominal pain followed by bloating and nausea as well as loose bowel movements. Soon he was having profuse watery diarrhea without odor. The stool is watery and white but the patient has no fever. Blood pressure is 95/62 lying down and drops to 75/40 standing. The skin turgor has reduced. HR is 110 and he looks ill with dry mucosa. V. cholerae was seen in dark-field microscopy of a fresh stool specimen. The lab study is as bellow: Sodium 137 meq/L Potassium 2 meq/L Chloride 94meq/L CO2 15 meq/L Fecal leukocytes None seen Fecal occult blood Negative

Clinical trial eligibility criteria: eligible ages (years): 18.0-75.0,  Gastrointestinal Inflammation Associated With CVID CVID Enteropathy AND FOR A subject is eligible for the study if all of the following are met Has given written informed consent Is male or female aged 18 through 75 years Has CVID or selective IgG subclass deficiency of either one or concomitant IgG subclasses comprising IgG1, IgG2, IgG3 or IgG4 (functional hypogammaglobulinemia) diagnosed prior to screening as based on the International Union of Immunological Societies (IUIS) criteria Has a documented, unintended loss of >5% of their body weight over the last year or requires nutritional supplements to maintain his/her body weight and/or has chronic diarrhea defined as a complaint of at >/= 50% of stools are non-formed for at least 4 consecutive weeks per patient history. Alternately, must be dependent on a therapeutic dose of antidiarrheals (e.g., loperamide or diphenoxylate with atropine) for control of chronic diarrhea If taking oral antibiotics chronically, must have used a stable dose of the antibiotic continuously for at least 2 weeks prior to start of screening period Is willing to have samples stored Be willing to consistently take appropriate measures to avoid pregnancy through the Week 48 study point. All subjects will be informed of the potential risks of ustekinumab during pregnancy and counseled on pregnancy avoidance appropriate to the subject s circumstances (e.g. fertility status, medical contraindications to hormonal birth control, and/or personal or religious beliefs regarding pregnancy avoidance). Subject to the judgment and discretion of the PI, some subjects may not need to take pregnancy avoidance measures. Patient handout on pregnancy avoidance will be provided to patients at the time of consent and discussion regarding pregnancy avoidance during the study. -Subjects who have previously been treated with a single 270 mg dose of ustekinumab on this study must be greater than 6 months from their treatment dose and have had recurrence of enteropathy symptoms. FOR A subject is excluded from the study if any of the following are met Has any clinically significant disease or condition (e.g., renal, hepatic, neurological, cardiovascular, pulmonary, endocrinologic, psychiatric, hematologic, urologic, or other acute or chronic illness) that in the opinion of the investigator would make the subject an unsuitable candidate for this trial, or put the subject at undue risk by participating in this study Is a woman who has a positive pregnancy test or who is breast-feeding