Subcutaneous immunoglobulins for the treatment of a patient with antisynthetase syndrome and secondary chronic immunodeficiency after anti-CD20 treatment: a case report

BACKGROUND Antisynthetase syndrome is a rare and debilitating multiorgan disease characterized by inflammatory myopathy, interstitial lung disease, cutaneous involvement, and frequent chronic inflammation of the joints. Standard treatments include corticosteroids and immunosuppressants. In some cases, treatment resistance may develop. Administration of immunoglobulins intravenously is recommended in patients with drug-resistant antisynthetase syndrome. CASE PRESENTATION Here, we describe the case of a 56-year-old woman of Algerian origin. She is the first case of a patient with multidrug-resistant antisynthetase syndrome featuring pulmonary involvement and arthropathy, and chronic secondary immune deficiency with recurrent infections, after anti-CD20 treatment, in which her primary antisynthetase syndrome-related symptoms and secondary immune deficiency were treated successfully with subcutaneous administration of immunoglobulin. The administration of immunoglobulin subcutaneously was introduced at a dose of 2 g/kg per month and was well tolerated. Clinical improvement was observed within 3 months of initiation of subcutaneous administration of immunoglobulin. After 22 months of treatment, she showed a significant improvement in terms of muscle strength, pulmonary involvement, arthralgia, and immunodeficiency. Her serum creatine phosphokinase and C-reactive protein levels remained normal. Finally, she was compliant and entirely satisfied with the treatment. CONCLUSIONS Taken together, these observations suggest that administration of immunoglobulin subcutaneously may be a useful therapeutic approach to tackle steroid-refractory antisynthetase syndrome while ensuring minimal side effects and improved treatment compliance. This treatment also allowed, in our case, for the regression of the chronic immunodeficiency secondary to rituximab treatment.