DECREASING IGG LEVELS IN A PATIENT WITH BRUTON'S AGAMMAGLOBULINEMIA: A CAUSE FOR INVESTIGATION

Abstract

<h3>Introduction</h3> This is the case of a 10-year-old boy with past medical history of Bruton's agammaglobulinemia receiving monthly IVIG infusions on prophylactic antibiotics who presented with decreasing IgG levels in the setting of acute on chronic appendicitis. <h3>Case Description</h3> The patient initially presented to the infusion unit for IVIG infusion. Upon patient's arrival, he reported nonspecific pressure-like, nonradiating 7/10 abdominal pain for eight days, worsened with coughing and sneezing. He described a history of chronic, recurrent loose stools for three months. He was evaluated by gastroenterology for work-up of protein-losing enteropathy, due to decreasing IgG levels, which was negative. No reported fevers, vomiting, diarrhea, constipation, dysuria or hematuria. Routine labs showed downtrending IgG levels despite monthly IVIG. He was taking azithromycin 250mg weekly for prophylaxis due to recurrent styes with good response. He was immediately referred to the ED. Physical examination showed RLQ tenderness and guarding with no rebound tenderness. A CBCD was normal; stool and blood cultures were negative. He was started on Ceftriaxone. An abdominal X-ray was normal and soft tissue US of the inguinal area ruled out hernia. An abdominal CT was consistent with acute appendicitis. He successfully underwent laparoscopic appendectomy. He was seen three weeks later in the Allergy and Immunology clinic with normal IgG levels. <h3>Discussion</h3> In patients with PIDD and on treatment with prophylactic antibiotics, the diagnosis of infections may be delayed. In the setting of decreasing IgG levels in patients on antibody replacement, further evaluation is warranted, as there may be an underlying chronic infection.