1391 Too Much of a Good Thing: HIV and Immune Reconstitution in a Patient With IGG4-Related Pancreatitis

Abstract

INTRODUCTION: Autoimmune pancreatitis accounts for 2% of cases of chronic pancreatitis. Autoimmune pancreatitis is differentiated into Type I (IgG4-related disease) and Type 2 (with normal IgG4 levels). Nearly 40% of patients with IgG4-related pancreatitis have involvement of salivary or lacrimal glands. CASE DESCRIPTION/METHODS: A 65 year-old-female with a history of HIV on anti-retroviral therapy (ART) (CD4 count of 588 cells/uL and undetectable viral load) and submandibular gland swelling presented with two weeks of epigastric discomfort and watery yellow diarrhea. The patient was noted to have elevated alkaline phosphatase to 802 U/L, aspartate aminotransferase to 284 U/L, alanine aminotransferase to 518, as well as total bilirubin of 2.8 mg/dL and direct bilirubin of 1.8 mg/dL. Amylase was 79 u/L and Lipase was 75 u/L. Four months prior to admission ART was changed from emtricitabine/tenofovir/raltegravir to bictegravir/emtricitabine/tenofovir; at that time CD4 count was 318 cells/uL. Liver tests were normal at that time. ART was held at the time of admission. Abdominal ultrasound demonstrated a diffusely enlarged, hypoechoic pancreas, consistent with pancreatitis. Magnetic resonance cholangiopancreatography showed abnormal morphology of the pancreas with loss of lobulation in the distal pancreatic body and tail, as well as irregularity of the pancreatic duct. Endoscopic ultrasound-guided biopsy with biliary stenting was performed. Prednisone was started empirically at 1 mg/kg/day for suspected IgG4 pancreatitis with rapid improvement in symptoms and liver tests. ART regimen was resumed simultaneously. Biopsy showed fibrosis with chronic inflammation, as well as the presence of IgG4 positive plasma cells. One month later, the patient's liver tests have returned to baseline. DISCUSSION: In this patient with a recent change in ART medications and newly elevated liver enzymes, drug-induced liver injury (DILI) can be considered initially. Imaging in this case showed diffuse edema and pancreatitis. Recent research suggests that patients with IgG4-related disease have over-activity of a specific class of cytotoxic CD4+ T cells driving the cytokine release that leads to its characteristic fibrosis. We suspect that this patient's flare of IgG4 pancreatitis may have been triggered by a recent change in her ART regimen. This allowed proliferation of all CD4+ T cell lines, leading to an response resembling the Immune Reconstitution Inflammatory Syndrome, resulting in the patient's clinical presentation.