Immune abnormalities in patients with Diamond-Blackfan anemia (DBA) appear to be independent of patient ribosomal protein genotype and steroid treatment, according to a report published in the British Journal of Haematology.
In this study, researchers sought to investigate the prevalence and nature of infections and immune defects in a large cohort of unselected patients with DBA who were genetically and phenotypically well characterized.
Immunodeficiency screening was conducted on 128 patients at the DBA Service of St Mary’s Hospital in the United Kingdom between July 2011 and November 2018. Data from 84% of these patients (107/128) — none of whom displayed evidence of severe bone marrow failure — were included in the study. Of the included patients, 63.9% (68/107) had experienced leukopenia or thrombocytopenia. In ribosomal protein genes, 70.3% of tested patients (71/101) had pathogenic mutations.
During the study period, 17.8% of patients (19/107) had significant infections, and an additional 31.8% of patients (34/107) self-reported high frequencies of infections. Lymphocyte counts were below the lower limit of the age-appropriate normal range at least once for 43% of patients (46/107). The most common deficits were seen in B cell and natural killer cell numbers, occurring in 29.2% and 25.5% of patients, respectively. Defective humoral immunity, measured as reduced serum immunoglobulin levels, occurred in 26.2% of patients (28/107); 24 patients had decreased immunoglobulin M levels, 7 patients had decreased immunoglobulin G levels, and 8 patients had decreased immunoglobulin A levels.
Overall, the researchers identified deficits in serum immunoglobulins or circulating T, natural killer, and B lymphocytes in 55.1% of patients (59/107). These abnormalities were independent of ribosomal protein genotype and occurred in patients who were treated with or without steroids.
“Our finding that impaired immunity arises independently of treatment regimen suggests that immune defects may be intrinsic to DBA; however, this could be clarified by larger prospective studies with longitudinal follow-up,” the authors concluded.
1. Iskander D, Roberts I, Rees C, et al. Impaired cellular and humoral immunity is a feature of Diamond-Blackfan anaemia; experience of 107 unselected cases in the United Kingdom [published online April 13, 2019]. Br J Haematol. doi:10.1111/bjh.15915