Persistant Eosinophilia in the Presence of Autoimmune Thyroiditis (ATD). Clues to the Diagnosis of Autoimmine Polyglandular Syndrome Type 2 (APS-2)?

Presentation Number: SUN 363
Date of Presentation: April 2nd, 2017

Bang Yu Xu*1, Mattar Shaikh Abdul Matin1, Manju Chandran2 and Donovan Tay1
1Seng Kang Health, 2Singapore General Hospital

Abstract

Background:

Autoimmune adrenalitis (AA) is the defining component in APS-2. It is usually found in conjunction with either ATD or T1DM. A high index of suspicion for identifying component disease in APS-2 is necessary as presentation can be subtle. We report a patient with eosinophilia leading to the diagnosis of Adrenal Insufficiency (AI) and subsequently APS-2 to reinforce this commonly understated association.

Clinical case:

A 39 year old male Bangladeshi construction worker, previously well, presented repeatedly to our institution with bilateral lower limb swelling and malaise over 2 months. Physical examination revealed presence of mild pitting edema to bilateral ankles without signs of inflammation or varicosities. He weighed 71 kg (BMI 27.3 kg/m2), was afebrile, normotensive and not tachycardic. Initial investigations showed leucopenia of 3890/mm3(4000- 10000), serum Na 141 mmol/L (135 – 145), Cr 57 umol/L (54 – 101) and albumin of 39 g/L (40 – 51). Proteinuria was absent and echocardiography showed a normal ejection fraction. Venous ultrasound excluded deep vein thrombosis. Primary hyperthyroidism was noted with elevated free T4 26.7 pmol/L (12.7 – 20.3) and low TSH 0.0014 mU/L (0.701 – 4.28).

Hyperthyroid symptoms, neck pain and family history of thyroid disorders or autoimmune diseases were absent. No goiter, bruit, tenderness over the thyroid gland or stigmata of Grave’s disease were found on focused examination. Buccal hyperpigmentation was noted. TRAb and TSI were negative at 0.7 IU/L (0.0 – 1.5) and 84% (50 – 179) respectively. TPO Ab, elevated at 411 U/ml (0.0 – 60.0), was consistent with ATD. In view of the likelihood of hashitoxicosis, he was managed expectantly for subsequent development of hypothyroidism.

Further review of his blood count showed mild anemia and persistent eosinophilia. His absolute eosinophil count was elevated at 4400/mm3(40 – 440). In view of malaise and eosinophilia in the setting of ATD, a 250 mcg synacthen test was performed which confirmed AI (basal cortisol 110 nmol/L (133 – 537); peak cortisol 294 nmol/L). ACTH elevated at 117.6 ng/L (1.0 - 60.0) indicative of primary AI. CT of the adrenals revealed atrophic adrenal glands consistent with AA. Additional laboratory workup suggested the presence of pernicious anemia with anti-parietal cell Ab positivity and a low normal vitamin B12 level. Hydrocortisone and vitamin B12 replacements were commenced.

Discussion

Reactive eosinophilia can occur in association with AI. Glucocorticoids induce eosinophil apoptosis and conversely glucocorticoids deficiency stimulates eosinophil proliferation and survival. Patients with undiagnosed AI presenting with eosinophilia is rare. This case serves to remind clinicians that fortuitous and otherwise potentially overlooked diagnosis of APS-2 can be made if evaluation for AI is done especially when eosinophilia occurs in the presence of ATD.

 

Nothing to Disclose: BYX, MSAM, MC, DT