438. Severe and high-dose glucocorticoid resistant thrombocytopaenia in IgG4-related (IgG4-RD)
Creators: name: Flores-Suárez1, Luis
Publisher: name: Zenodo
Year: 2022
Subjects: Vasculitis
ANCA
Abstracts
Giant Cell Arthritis
MPA
GPA
EGPA
Takayasu
IgA vasculitis

description: <strong>Presentation of Case: </strong>A previously healthy 65 years-old male presented in October 2019 with painless bilateral parotid gland growth, followed by mouth dryness and arthralgias of elbows, ankles, and MCP joints. On physical examination, submandibular and parotid gland enlargement, synovitis on both wrists and left elbow were noticed. Primary Sjögren syndrome (PSS) was suspected, and due to arthritis, prednisone (PDN) started at 10 mg qd. A biopsy of major salivary glands was proposed but refused. He continued with PDN in descent until 2.5 mg qd with improvement. Low C3 and C4 levels, and raised total serum globulins returned to normal. In October 2020 new parotid gland enlargement occurred. January 2021: he had COVID-19 while on PDN 7.5 mg qd with no need for hospitalisation although he had low oxygen saturation. He was treated by another physician with apparently no sequelae and vaccinated later. April 2021: on a follow-up visit, while being asymptomatic, mild leucopaenia (3850/uL) and platelets of 106,000/uL were noticed. Thought to be post-COVID-19 related, he was left untreated; PDN was tapered to 5 mg qd. August 2021: three months previously, he developed large spontaneous ecchymoses, and carpal and PIP arthralgias. Non-palpable purpura and ecchymoses on legs were seen. He had severe thrombocytopaenia (10,210/uL) as single blood cell count abnormality. After haematological consultation, he was prescribed 40 mg qd dexamethasone, but after 5 days platelets went down to 4,000/uL, and was given IV-methylprednisolone 1 g for 3 days. However, he developed pneumonia and required hospitalisation in a social security facility for IV treatment. As inpatient, he was studied by haematologists and rheumatologists. Search for SLE, PAPS, PSS was negative. A bone marrow aspirate showed increased megacariocytes. No vacuoles were seen on bone marrow precursors. IVIG 2 g/kg/day was given for 3 days. He did not develop complications and was discharged 2 weeks later with 37,000 platelets/uL and PDN 40 mg qd. On the latest visit one month after discharge, there were no signs of bleeding, no enlarged salivary glands or lymph nodes. His platelets however remain under 50,000/uL. <strong>Diagnostic Testing: </strong>On first evaluation: negative Shirmer´s test, normal ESR, RF, mild fatty liver on abdominal US, normal pancreas. Neck and thoracic CT: posterior cervical lymph nodes, parotid, and submandibular salivary glands enlargement. Low C3 and C4 levels, negative anti-Ro and anti-La, homogeneous 1:640 ANA, serum globulins 3.39 g/dL (upper limit-UL 3), total IgG 2780.3 mg/dL (UL 1822), normal IgG1 to 3 levels, IgG4 1240 mg/dL (UL 201; 6.16x). Normal serum amylase, lipase, and liver function tests. Baseline platelets: 170,000/uL. During the thrombocytopaenic episode, other causes were reasonably discarded. <strong>Differential &amp; Final Diagnosis: </strong>PSS and malignancies have been considered, without supporting evidence. IgG4-RD was suspected based on the exclusion of other maladies. According to the 2019 ACR/EULAR criteria, the patient fits the diagnosis (steps 1 and 2 fulfilled, 30 points). <strong>Discussion of Management: </strong>Thrombocytopaenia is an unusual feature of IgG4-RD. Few cases have been described, and some have also had a protracted course in spite of high-dose glucocorticoid and IVIG therapy, with slow recovery of normal platelet counts and the need for additional treatments. To this date, my therapeutic aim points to RTX prescription but he depends on approval by the public health system due to its cost. <strong>Conclusions: </strong>An unusual case of thrombocytopaenia in the context of group 3 IgG4-RD is presented without other alternative proven cause. As seen in other reports, return to normal platelet counts can be slow with usual glucocorticoid therapy and may require other pharmacological interventions. <strong>Disclosures</strong> Informed consent was obtained from the patient. Nothing else to disclose.