Endocrine Abstracts

Introduction: Asplenia has been reported in 10% of patients with type 1 APS (APS-1), but has never been reported in APS-2. We describe a patient with presumed APS-2 and aplenia.

Case report: A 69-year-old woman was diagnosed with B12 deficiency with severe anemia at age 21 and insulin dependent diabetes mellitus at age 33, following routine testing. At 59, she was hospitalized with salt wasting and a diagnosis of Addison’s disease was made, which was subsequently confirmed by an inadequate response to tetracosactide stimulation. The diagnosis of subclinical Hashimoto’s thyroiditis was concurrently made. The patient had chronic onychomychosis of one fingernail and multiple toenails, but never of the mucous membranes and has never reported tetany. The diagnosis of APS-2 was made, based on the presence of the complete tri-glandular syndrome. The patient was under active surveillance for other autoimmune manifestations, but none has so far been detected. Her past history is negative for serious illnesses or infections and has never had abdominal surgery. Of note, she had never received a pneumococcal vaccine. Her family history is negative for autoimmune disorders. An abdominal CT scan was requested for complaints of non-specific abdominal discomfort and an incidental observation regarding the absence of an orthotopic spleen was made. An abdominal ultrasound found evidence of a hypoplastic splenic vessel. Functional imaging of the spleen using 99mTC-colloid failed to reveal a functional spleen. Relevant laboratory investigations including peripheral blood smear revealed Howell-Jolly bodies. Parathormone and electrolytes were normal. Quantitative measurements of major immunoglobulin classes and T lymphocyte subpopulations were normal. HLA II haplotypes DQB1*05 and DQA1*01 were indentified. AIRE sequencing is pending.

Conclusion: Asplenia in the context of well-defined APS-2 and in the absence of clinical immunodeficiency, is a novel finding that challenges our current understanding of APS and needs to be further investigated.