Extended clinical and immunological phenotype and transplant outcome in CD27 and CD70 deficiency

Abstract

Biallelic mutations in the genes encoding CD27 or its ligand CD70 underlie inborn errors of immunity (IEIs) characterized predominantly by Epstein-Barr virus (EBV)-associated immune dysregulation, such as chronic viremia, severe infectious mononucleosis, hemophagocytic lymphohistiocytosis (HLH), lymphoproliferation, and malignancy. A comprehensive understanding of the natural history, immune characteristics, and transplant outcomes has remained elusive. Here, in a multi-institutional global collaboration, we collected the clinical information of 49 patients from 29 families (CD27, n = 33; CD70, n = 16), including 24 previously unreported individuals and identified a total of 16 distinct mutations in CD27, and 8 in CD70, respectively. The majority of patients (90%) were EBV+ at diagnosis, but only ∼30% presented with infectious mononucleosis. Lymphoproliferation and lymphoma were the main clinical manifestations (70% and 43%, respectively), and 9 of the CD27-deficient patients developed HLH. Twenty-one patients (43%) developed autoinflammatory features including uveitis, arthritis, and periodic fever. Detailed immunological characterization revealed aberrant generation of memory B and T cells, including a paucity of EBV-specific T cells, and impaired effector function of CD8+ T cells, thereby providing mechanistic insight into cellular defects underpinning the clinical features of disrupted CD27/CD70 signaling. Nineteen patients underwent allogeneic hematopoietic stem cell transplantation (HSCT) prior to adulthood predominantly because of lymphoma, with 95% survival without disease recurrence. Our data highlight the marked predisposition to lymphoma of both CD27- and CD70-deficient patients. The excellent outcome after HSCT supports the timely implementation of this treatment modality particularly in patients presenting with malignant transformation to lymphoma.

Graphical abstract

Figure 1.

Clinical and genetic features of patients harboring mutations in CD27 and CD70. (A) Identified variants in CD27 (top) and CD70 (bottom). Corresponding publications for previously reported mutations are indicated in brackets. (B) Comparison of clinical findings and outcomes in CD27- and CD70-deficient patients. (C) Clinical manifestations of CD27 and CD70 deficiencies. IBD, inflammatory bowel disease; RTI, respiratory tract infection.

Figure 2.

Clinical course of patients having CD27 and CD70 mutations. The scheme depicts the main clinical characteristics, therapeutic interventions, and outcome of CD27- and CD70-deficient patients within the follow-up time of each individual patient (P).

Figure 3.

Impact of CD27 and CD70 mutations in lymphocyte differentiation in vivo: lymphocytes and subsets. PBMCs from healthy controls (n = 18-26), CD27-deficient patients (n = 10), or CD70-deficient patients (n = 7-11) were labeled with mAbs against CD3, CD4, CD8, CD56, CD20, CD10, CD27, CD161, TCR Vβ11, TCR Vα7-2, TCR Vα24, CCR7, and CD45RA. (A) Proportions of total (CD3⁺), CD4⁺ (CD3⁺CD4⁺CD8⁻), and CD8⁺ (CD3⁺CD4⁻CD8⁺) T cells, B cells (CD20⁺), and NK cells (CD3⁻CD56⁺) in peripheral lymphocytes of healthy donors and patients. (B) Ratio of CD4/CD8 T cells. (C) Proportions of CD3⁺ T cells expressing αβ or γδ TCR. (D-E) proportions of MAIT (D) or NKT (E) cells within the total CD3⁺ T-cell population. (F) Proportions of CD56^high and CD56^dim NK subsets within the total NK population. (G) Proportions of transitional, naive, and memory B cells within the total B-cell population. (H-I) Proportion of CD4⁺ (H) and CD8⁺ (I) cells with a naive, T_CM, T_EM, or T_EMRA phenotype. Statistics performed using ANOVA. *P < .05; ** P < .01; ****P < .0001.

Figure 4.

CD8 T-cell function. CD27 deficiency compromises effector function and survival of CD8⁺ T cells. (A-B) PBMCs were stained with mAbs to CD8, CCR7, CD45RA, granzyme B, and perforin. Expression levels of (A) granzyme B or (B) by CD8⁺ T_CM, T_EM, and T_EMRA cells were determined relative to naive CD8⁺ T cells (normalized to 1.0). (C) PBMCs from healthy individuals (n = 5) and CD27-deficient individuals (n = 5) were stimulated for 14 hours (PMA/ionomycin) in the presence of brefeldin A and monensin. Percentage of cells expressing IFNγ, TNF, IL-2, or CD107a was determined by intracellular staining and flow cytometric analysis. (D-E) CD8⁺ memory (T_CM/T_EM; D) and T_EMRA (E) cells were sort-purified from healthy individuals (n = 6) and CD27-deficient individuals (n = 4) and cultured with anti-CD2/CD3/CD28 mAbs for 5 days. Proportions of cells expressing IFNγ, CD107a, or perforin were determined by intracellular staining and flow cytometry; secretion of IFNγ, TNFα, IL-2, and granzyme A and B was determined by cytometric bead arrays. (F-G) PHA blasts were expanded from PBMCs from healthy donors (n = 5) and CD27-deficient patients (n = 3). After 5 to 7 days, the cells were restimulated with plate-bound α-CD3. (F) Percentage of apoptotic cells was determined after 24 hours. (G) Relative expression of FASLG expression was determined after 4 hours stimulation with α-CD3 mAb (normalized to PHA blasts from healthy donors). For all graphs, values represent mean plus or minus SEM. Statistics performed using Student t tests with Mann-Whitney tests. *P < .05; ** P < .01.

Figure 5.

Impaired generation and function of EBV-specific CD8⁺ T cells in CD27-deficient individuals. (A-B) PBMCs from healthy HLA-mismatched, HLA-matched (n = 4-8), and CD27-deficient patients (n = 4-7) were stained with specific EBV- or CMV-peptide-MHC class I tetramers, mAbs to CD4, CD8, CCR7, CD45RA, CD57, CD95, PD-1, 2B4, and NKG2D. EBV-specific and CMV-specific CD8⁺ T cells quantified in HLA-mismatched or -matched controls and CD27-deficient patients, presented for all individuals as well as based on the specific HLA alleles (HLA-A*0201, HLA-A*2402, or HLA B*0702). Statistics were performed using ANOVA; *P < .05. (C) Distribution of EBV-specific CD8⁺ T cells in the naive, T_CM, T_EM, and T_EMRA CD8⁺ T-cell populations in HLA-matched controls and CD27-deficient patients. (D) Expression of 2B4 and NKG2D on EBV-specific CD8⁺ T cells from healthy control and CD27-deficient patients. (E) Relative expression of 2B4 and NKG2D on EBV- and CMV-specific CD8⁺ T cells from CD27-deficient patients determined by calculating fold change relative to virus-specific CD8⁺ T cells from HLA-matched donors. (F) PBMCs were stained ex vivo with EBV-specific HLA tetramer, and mAbs to CD8, granzyme B, and perforin. Expression of granzyme B or perforin in EBV-specific CD8⁺ T cells from CD27-deficient patients was determined relative to that in EBV-specific CD8⁺ T cells from healthy donors.