410. Unusual Interstitial Lung Changes in Type I Cryoglobulinemic

Presentation of Case: Type 1 cryoglobulinemic vasculitis is a subtype of cryoglobulinemic vasculitis characterized by precipitated immunoglobulin complexes that circulate in plasma and may occlude medium- and small-sized vessels. Commonly affected organ systems include the skin, kidneys, and peripheral nervous system. Pulmonary system involvement is rare. A 42-year-old man was admitted to hospital in the Spring of 2020 when he presented with purpuric lesions, fingertip ulcerations, arthritis and dry cough. He was found to have type I cryoglobulinemia secondary to paraproteinemia via monoclonal gammopathy of undetermined significance (MGUS), kappa light chain IgG subtype.

Diagnostic Testing: A CT chest at that time was normal. He initially responded to steroids and he was prescribed cyclophosphamide. This was stopped due to profound neutropenia requiring dose reduction and Filagistrim. Steroids were tapered. At review by Hematology, it was felt that intervention was not indicated for his MGUS. During this period of time his cough progressed and he developed dyspnea on exertion. He was then referred for management to a combined Rheumatology & Respirology clinic. 

Differential & final Diagnosis: Upon review at the combined clinic he was found to be hypoxic and CXR demonstrated mixed interstitial and airspace disease. His presenting symptoms of fatigue, night sweats, digital ischemia and purpuric lesions had returned. He was reinitiated on prednisone. A follow-up CT revealed continued bibasilar opacities, ground-glass changes, and septal thickening. COVID-19 screen was negative. Bronchoscopy and bronchoalveolar lavage were negative for alveolar hemorrhage and infection. Surgical lung biopsy revealed organizing pneumonia with fibrosis. At this point an application for Rituximab was made and prednisone was increased to 50 mg with clinical response.

Discussion of Management: A follow-up pulmonary function test revealed improved but persisting moderately-severe restrictive impairment, with significant diffusion impairment (44%). Recent CT has also shown reticulation and traction changes indicative of progression of interstitial lung disease. Currently, he is much improved clinically and has been able to return to work. Over four months, his cutaneous manifestations improved and are now managed with calcium channel blockers. 

Conclusion: This case illustrates a unique scenario of interstitial lung changes in the context of type I cryoglobulinemic vasculitis; although pulmonary vasculitis may be associated with diffuse alveolar hemorrhage, interstitial lung changes are not commonly encountered. This case shows an example of interstitial lung changes in context of cryoglobulinemic vasculitis that responded to treatment with high-dose steroids and Rituximab.

Disclosures: SG honorarium Pfizer Sanofi: Clinical Trial AbbVie: Clinical Trial  Roche: Educational Grant; Novartis: Advisory Board.