Stimulator of interferon genes (STING)-associated vasculopathy with onset in infancy (SAVI) is a very rare autoinflammatory disease related to
STING1
mutation. SAVI is mainly characterized by fever ...attacks and skin and respiratory manifestations such as interstitial lung disease or alveolar hemorrhage. Respiratory involvement occurs in 80% of cases and might progress to severe lung fibrosis and require lung transplantation (LT). Three patients with SAVI who underwent LT have been reported to date. Two of the three patients died months or years after LT due to multiple organ failure or sepsis. However, the diagnosis of SAVI was made after LT, thus preventing the use of targeted therapy, such as the Janus kinase 1 and 2 inhibitor (JAK1/2i) ruxolitinib, which might be beneficial for the respiratory status of these patients. We aimed to report our experience in managing three patients who were followed in three large lung transplantation centers in France and who benefited from ruxolitinib before undergoing LT. We describe posttransplant complications that occurred as well as outcomes.
The burden of CMV infection and disease is important in pediatric hematopoietic stem cell transplantation (HSCT), notably in the subgroup of patients with inborn errors of immunity (IEIs). Letermovir ...(LMV) is now a standard of care for CMV prophylaxis in adult sero-positive (R+) recipients, but is not yet labeled for children. Published pediatric studies are still scarce. We report a monocentric real-life use of LMV in 36 HSCT pediatric recipients with IEIs considered at high-risk of CMV infection including 14 patients between 2 and 12 months of age. A homogenous dosage proportional to the body surface area was used. Pharmacokinetic (PK) was performed in 8 patients with a median of 6 years of age (range 0,6;15). The cumulative incidence of clinically significant CMV infections (CS-CMVi) and the overall survival of patients under LMV were compared to a very similar historical cohort under (val)aciclovir prophylaxis. LMV tolerance was good. As compared to the historical cohort, the incidence of CS-CMVi was significantly lower in LMV group (5 out of 36 transplants (13.9%) versus 28 of the 62 HSCT (45.2%)) (p = 0.002). Plasma LMV exposures did not significantly differ with those reported in adult patients. In this high-risk pediatric HSCT cohort transplanted for IEIs, CMV prophylaxis with LMV at a homogenous dosage was well tolerated and effective in preventing CS-CMVi compared with a historical cohort.
Autoimmune lymphoproliferative syndrome (ALPS) caused by impaired FAS-mediated apoptosis of lymphocytes is characterized by lymphoproliferation, autoimmunity, but also an increased risk of invasive ...bacterial infection, notably following splenectomy. We surveyed a cohort of 100 ALPS patients (including 33 splenectomized) and found that 12 (10 splenectomized) had experienced 23 invasive bacterial infections mainly caused by Streptococcus pneumoniae. This vulnerability was associated with evidence of defective B-cell function characterized by low serum immunoglobulin (Ig) M, low IgM antibody production in response to S pneumoniae following nonconjugated immunization, and low blood memory B-cells counts (including marginal zone MZ B-cell counts). This immunodeficiency strongly correlated with intensity of lymphoproliferation. Spleen sections from 9 ALPS patients revealed double-negative T-cell (DN-T) infiltration of the MZ, which was depleted of B cells. MZ in ALPS patients contained an abnormally thick layer of MAdCAM-1(+) stromal cells and an excess of DN-Ts. DN-Ts were shown to express MAdCAM-1 ligand, the α4β7 integrin. These observations suggest that accumulating DN-Ts are trapped within stromal cell meshwork and interfere with correct localization of MZ B cells. Similar observations were made in spleens of fas-deficient mice. Our data revealed an unexpected mechanism by which ALPS results in anti-polysaccharide IgM antibody production–specific defect. Splenectomy should be avoided.
•ALPS predisposes to invasive bacterial infections, notably following splenectomy, and is associated with defective B-cell function.•Poor anti-polysaccharide IgM antibody production and spleen MZ disorganization correlate with lymphoproliferation.
Background The inclusion of severe combined immunodeficiency (SCID) in a Europe-wide screening program is currently debated. Objective In making a case for inclusion in the French newborn screening ...program, we explored the costs incurred and potentially saved by early management of SCID. Methods For test costs, a microcosting study documented the resources used in a laboratory piloting a newborn screening test on Guthrie cards using the T-cell receptor excision circle quantification method. For treatment costs, patients with SCID admitted to the national reference center for primary immunodeficiency in France between 2006 and 2010 were included. Costs of admission were estimated from actual national production costs. We estimated the costs for patients who underwent early versus delayed hematopoietic stem cell transplantation (HSCT; age, ≤3 vs >3 months, respectively). Results The unit cost of the test varied between €4.69 and €6.79 for 33,800 samples per year, depending on equipment use and saturation. Of the 30 patients included, 27 underwent HSCT after age 3 months. At 1 year after HSCT, 10 of these had died, and all 3 patients undergoing early transplantation survived. The medical costs for HSCT after 3 months were €195,776 (interquartile range, €165,884-€257,160) versus €86,179 (range, €59,014-€272,577) when performed before 3 months of age. In patients undergoing late transplantation, active infection contributed to high cost and poor outcome. Conclusion Early detection of SCID could reduce the cost of treatment by €50,000-100,000 per case. Assuming a €5 unit cost per test, the incidence required to break even is 1:20,000; however, if the survival advantage of HSCT before 3 months is confirmed, universal screening is likely to be cost-effective.
Background
We conducted a national multicenter retrospective study in France to evaluate the efficacy and tolerance of ruxolitinib in children with steroid‐refractory acute graft‐versus‐host disease ...(aGVHD) after allogeneic hematopoietic stem cell transplant.
Procedure
Patients were recruited from the 15 pediatric transplantation centers. Transplanted patients were eligible if they met the following criteria: aged ≤ 18 years at transplantation, receiving a myeloablative allogeneic hematopoietic stem cell transplant, having an aGVHD of grade ≥2, and treated with ruxolitinib for steroid‐refractory aGVHD.
Results
Twenty‐nine patients received ruxolitinib for steroid‐refractory aGVHD. Six patients achieved a complete response at day 28 after the start of treatment but finally 19 patients (65.5%) achieved a complete response (CR) with a median delay of 41 days (5‐93 days). Two patients had a partial response. All patients who achieved CR or partial response discontinued corticosteroid treatment. Eight patients showed treatment failure. The overall response rate was 72.4%. Twenty‐three of 29 patients were alive at a median follow‐up of 685 days (177‐1042 days) after the hematopoietic stem cell transplantation. Viral replication was observed in 41.4% of cases. We did not observe severe hematological adverse events and cytopenia requiring a modification of ruxolitinib doses always resolved. The median initial dose of ruxolitinib was 12.6 mg/m2/day with an important range. We could not demonstrate any relationship between initial dose and effectiveness.
Conclusion
Ruxolitinib may constitute a promising second‐line treatment for children with steroid‐refractory aGVHD that should be validated in a prospective large‐scale pharmacokinetic and efficacy trial.
During the last decade, gene therapy via ex vivo gene transfer into autologous hematopoietic stem cells has emerged as a convincing therapy for severe combined immunodeficiency caused by ILR2G ...mutation (SCID-X1) despite the occurrence of genotoxicity caused by the integration of first-generation retroviral vectors. However, the place of gene therapy among the therapeutic armamentarium remains to be defined. We retrospectively analyze and compare clinical outcomes and immune reconstitution in 13 consecutive SCID-X1 patients having undergone haploidentical hematopoietic stem cell transplantation (HSCT) and 14 SCID-X1 patients treated with gene therapy over the same period at a single center level: the Necker Children's Hospital (Paris, France). Our results show a clear advantage in terms of T-cell development of gene therapy over HSCT with a mismatched donor. Patients treated with gene therapy display a faster T-cell reconstitution and a better long-term thymic output. Interestingly, this advantage of gene therapy vs haploidentical HSCT seems to be independent of the existence of clinical graft-versus-host disease in the latter condition. If data of safety are confirmed over the long term, gene therapy for SCID-X1 appears to be an equal, if not superior, alternative to haploidentical HSCT.
•SCID-X1 patients treated with gene therapy show faster T-cell development compared with patients treated with haploidentical HSCT.
We studied T-cell reconstitution in 31 primary T-cell–immunodeficient patients who had undergone hematopoietic stem-cell transplantation (HSCT) over 10 years previously. In 19 patients, there was no ...evidence of myeloid chimerism because little or no myeloablation had been performed. Given this context, we sought factors associated with good long-term T-cell reconstitution. We found that all patients having undergone full myeloablation had donor myeloid cells and persistent thymopoiesis, as evidenced by the presence of naive T cells carrying T-cell receptor excision circles (TRECs). In 9 patients with host myeloid chimerism, sustained thymic output was also observed and appeared to be associated with γc deficiency. It is therefore possible that the complete absence of thymic progenitors characterizing this condition created a more favorable environment for thymic seeding by a population of early progenitor cells with the potential for self-renewal, thus enabling long-term (> 10 years) T-cell production.
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