Prevalence of hypogammaglobulinemia and its management with subcutaneous immunoglobulin supplementation in patients after allogeneic hematopoietic stem cell transplantation- a single-center analysis

Abstract PURPOSE Secondary immunodeficiencies are frequently observed after allo-HSCT. This study aimed to assess the prevalence and management of hypogammaglobulinemia requiring immunoglobulin.METHODS A retrospective single-institution study involved 126 adult patients transplanted in 2012–2019 for hematological malignancies. Patients were tested every 2–3 weeks for plasma IgG concentration during the 1st year after transplantation and supplemented with facilitated subcutaneous immunoglobulin when they met pre-defined criteria.RESULTS The IgG concentration < 500mg/dL was diagnosed in 41 patients, while 500700mg/dL in 25 and altogether 53 patients required IgG supplementation. The median number of IgG administrations was 2. The median time to the first IgG administration after allo-HSCT was 4.1 months, while to the next administration (if more than one was required)- 53 days (prophylactic group) and 32 days(group with infections). We did not observe any significant toxicity. The 1-y overall survival in the supplemented group with infections and IgG 500-700mg/dL was significantly lower than compared to no-need immunoglobulin group (p = 0.009). The diagnosis with Acute Lymphoblastic Leukemia (ALL) or Chronic Lymphocytic Leukemia (CLL) and the use of systemic corticosteroids were associated with the average probability of hypogammaglobulinemia requiring IgG supplementation in 83.8% (versus 39.3%, p = 0.000 for other diagnosis) and 64.2% (versus 31.5%, p = 0.005 for patients without systemic corticosteroids) respectively.CONCLUSION Over 40% of the adult recipients may require at least incidental immunoglobulin supplementation during the first year after allo-HSCT. Low IgG concentrations are associated with inferior outcomes. The subcutaneous route of IgG administration appeared to be safe and may allow for long persistence.