Primary Intestinal Lymphangiectasia as a cause of secondary combined immunodeficiency: case study and literature review.

Primary intestinal lymphangiectasia (PIL) is a rare disorder characterized by the dilation of intestinal lymphatic vessels, resulting in lymph loss. We present the case of an eleven-year-old male, referred to immunology after recurrent Cryptosporidium infections. PIL was confirmed after stool studies, endoscopy and imaging. Clinical immunophenotyping revealed combined immunodeficiency, with severe hypogammaglobulinemia (IgG: 212 mg/dL) and T cell lymphopenia (CD4+ count: 172 cells/μL; CD8+ count: 208 cells/μL). After treatment with subcutaneous immunoglobulin and trimethoprim/sulfamethoxazole prophylaxis, immune parameters remained suboptimal, and dietary strategies were implemented. This intervention resulted in improvement in his IgG level, rising to 1114 mg/dL, although T cell lymphopenia remained. We discuss the clinical course of this patient and provide an overview of the published literature regarding immunodeficiency associated with PIL. We conclude that PIL should be considered as a cause of secondary combined immunodeficiency in the absence of an alternative explanation in both adult and pediatric patients.