A treosulfan (Treo)-based conditioning regimen prior to hematopoietic stem cell transplantation (HSCT) has been successfully used in treating hematological malignant and nonmalignant diseases. We report Treo pharmacokinetics (PK) in patients with thalassemia major undergoing HSCT (n = 87), receiving Treo at a dose of 14 g/m /day. Median Treo AUC and clearance (CL) was 1,326 mg*h/L and 10.8 L/h/m , respectively. There was wide interindividual variability in Treo AUC and CL (64 and 68%) which was not explained by any of the variables tested. None of the Treo PK parameters were significantly associated with graft rejection or toxicity; however, Treo CL <7.97 L/h/m was significantly associated with poor overall (hazard ratio (HR) 2.7, confidence interval (CI) (1.09-6.76), P = 0.032) and event-free survival (HR 2.4, CI (0.98-5.73), P = 0.055). Further studies in a larger cohort are warranted to identify the factors explaining the variation in Treo PK as well as to establish a therapeutic range of Treo for targeted dose adjustment to improve HSCT outcome.

Introduction Nuwiq® (Human‐cl rhFVIII) is a fourth generation recombinant FVIII, produced in a human cell line, without chemical modification or protein fusion. No inhibitors developed in studies with Nuwiq® in 201 previously treated patients with haemophilia A (HA). The immunogenicity, efficacy and safety of Nuwiq® in previously untreated patients (PUPs) with severe HA are being assessed in the ongoing NuProtect study. Methods The study, conducted across 38 centres worldwide, is evaluating 110 true PUPs of all ages and ethnicities enrolled for study up to 100 exposure days (EDs) or 5 years maximum. The primary objective is to assess the immunogenicity of Nuwiq® (inhibitor activity ≥0.6 BU) using the Nijmegen‐modified Bethesda assay at a central laboratory. Results Data for 66 PUPs with ≥20 EDs from a preplanned interim analysis were analysed. High‐titre (HT) inhibitors developed in 8 of 66 patients after a median of 11.5 EDs (range 6‐24). Five patients developed low‐titre inhibitors (4 transient). The cumulative incidence (95% confidence interval) was 12.8% (4.5%, 21.2%) for HT inhibitors and 20.8% (10.7%, 31.0%) for all inhibitors. During inhibitor‐free periods, median annualized bleeding rates during prophylaxis were 0 for spontaneous bleeds and 2.40 for all bleeds. Efficacy was rated as “excellent” or “good” in treating 91.8% of bleeds. Efficacy of surgical prophylaxis was “excellent” or “good” for 8 (89%) procedures and “moderate” for 1 (11%). No tolerability concerns were evident. Conclusion These interim data show a cumulative incidence of 12.8% for HT inhibitors and convincing efficacy and tolerability in PUPs treated with Nuwiq®.

BackgroundChronic granulomatous disease (CGD) is an inherited defect in phagocytic respiratory burst that results in severe and life-threatening infections in affected children. Single center studies from India have shown that proportion of autosomal recessive (AR) CGD is more than that reported from the West. Further, affected patients have high mortality rates due to late referrals and difficulties in accessing appropriate treatment. However, there is lack of multicentric collaborative data on CGD from India.ObjectiveTo describe infection patterns, immunological, and molecular features of CGD from multiple centers in India.MethodsA detailed proforma that included clinical and laboratory details was prepared and sent to multiple centers in India that are involved in the care and management of patients with inborn errors of immunity. Twelve centers have provided data which were later pooled together and analyzed.ResultsOf the 236 patients analyzed in our study, X-linked and AR-CGD was seen in 77 and 97, respectively. Male female ratio was 172:64. Median age at onset of symptoms and diagnosis was 8 and 24 months, respectively. Common infections documented include pneumonia (71.6%), lymphadenitis (31.6%), skin and subcutaneous abscess (23.7%), blood-stream infection (13.6%), osteomyelitis (8.6%), liver abscess (7.2%), lung abscess (2.9%), meningoencephalitis (2.5%), splenic abscess (1.7%), and brain abscess (0.9%). Forty-four patients (18.6%) had evidence of mycobacterial infection. Results of molecular assay were available for 141 patients (59.7%)—CYBB (44.7%) gene defect was most common, followed by NCF1 (31.9%), NCF2 (14.9%), and CYBA (8.5%). While CYBA variants were documented only in Southern and Western parts of India, a common dinucleotide deletion in NCF2 (c.835_836delAC) was noted only in North Indian population. Of the 174 patients with available outcome data, 67 (38.5%) had expired. Hematopoietic stem cell transplantation was carried out in 23 patients, and 12 are doing well on follow-up.ConclusionsIn India, proportion of patients with AR-CGD is higher as compared to Western cohorts, though regional differences in types of AR-CGD exist. Clinical profile and mortality rates are similar in both X-linked and AR-CGD. However, this may be a reflection of the fact that milder forms of AR-CGD are probably being missed.

Mixed chimerism (MC) occurs frequently after allogeneic hematopoietic stem cell transplantation (HSCT) for thalassemia major (TM) and may be associated with rejection. We report the outcome of MC in 132 TM patients conditioned with Busulphan/Cyclophosphamide, who had successful engraftment and had ⩾1 year follow-up. Chimerism was first assessed at day +28, then every 3-9 months or more frequently if there was MC. If rejection was suspected, immunosuppression was stopped and donor-lymphocyte infusion (DLI) was given if there was no response. Among 132 patients, aged 7 years (range: 2-24), 46/132 (34.8%) had MC in the first year, 32/46 (69.6%) at day +28 and another 14 (30%) between day +28 and 1 year post HSCT. MC was quantified at level 1 (residual host chimerism (RHC) <10%) in 20 (43.5%), level II (RHC 10-25%) in 14 (30.4%) and level III (RHC >25%) in 12 (26.1%). On tapering immunosuppression, 15 (32.6%) developed acute GvHD and 8 (17.4%) had chronic GvHD with reversal to complete chimerism (CC). DLI was administered to 5/46 (10.9%), 1 evolved to CC but 4 rejected the graft. At median follow-up of 60 months (range: 16-172), 20/46 (43.5%) had CC, 18/46 (39.1%) had persistent MC with hemoglobin of 11.5 g/dL (range: 8.4-13.6), whereas 8 (17.4%) rejected the graft. Close monitoring and early intervention is needed with increasing recipient chimerism. Novel strategies are required for preventing graft rejection.

The standard of care for patients with acute promyelocytic leukaemia (APL) relapsing after front-line treatment with arsenic trioxide (ATO)based regimens remains to be defined. A total of 67 patients who relapsed after receiving ATO-based up-front therapy and were also salvaged using an ATO-based regimen were evaluated. The median (range) age of patients was 28 (4-54) years. While 63/67 (94%) achieved a second molecular remission (MR) after salvage therapy, three (4Á5%) died during salvage therapy. An autologous stem cell transplant (auto-SCT) was offered to all patients who achieved MR, 35/63 (55Á6%) opted for auto-SCT the rest were administered an ATO + all-trans retinoic acid maintenance regimen. The mean (SD) 5-year Kaplan-Meier estimate of overall survival and event-free survival of those who received auto-SCT versus those who did not was 90Á3 (5Á3)% versus 58Á6 (10Á4)% (P = 0Á004), and 87Á1 (6Á0)% versus 47Á7 (10Á3)% (P = 0Á001) respectively. On multivariate analysis, failure to consolidate MR with an auto-SCT was associated with a significantly increased risk of relapse [hazard ratio (HR) 4Á91, 95% confidence interval (CI) 1Á56-15Á41; P = 0Á006]. MR induction with ATO-based regimens followed by an auto-SCT in children and young adults with relapsed APL who were treated with front-line ATO-based regimens was associated with excellent longterm survival.

BackgroundSevere Combined Immune Deficiency (SCID) is an inherited defect in lymphocyte development and function that results in life-threatening opportunistic infections in early infancy. Data on SCID from developing countries are scarce.ObjectiveTo describe clinical and laboratory features of SCID diagnosed at immunology centers across India.MethodsA detailed case proforma in an Excel format was prepared by one of the authors (PV) and was sent to centers in India that care for patients with primary immunodeficiency diseases. We collated clinical, laboratory, and molecular details of patients with clinical profile suggestive of SCID and their outcomes. Twelve (12) centers provided necessary details which were then compiled and analyzed. Diagnosis of SCID/combined immune deficiency (CID) was based on 2018 European Society for Immunodeficiencies working definition for SCID.ResultsWe obtained data on 277 children; 254 were categorized as SCID and 23 as CID. Male-female ratio was 196:81. Median (inter-quartile range) age of onset of clinical symptoms and diagnosis was 2.5 months (1, 5) and 5 months (3.5, 8), respectively. Molecular diagnosis was obtained in 162 patients - IL2RG (36), RAG1 (26), ADA (19), RAG2 (17), JAK3 (15), DCLRE1C (13), IL7RA (9), PNP (3), RFXAP (3), CIITA (2), RFXANK (2), NHEJ1 (2), CD3E (2), CD3D (2), RFX5 (2), ZAP70 (2), STK4 (1), CORO1A (1), STIM1 (1), PRKDC (1), AK2 (1), DOCK2 (1), and SP100 (1). Only 23 children (8.3%) received hematopoietic stem cell transplantation (HSCT). Of these, 11 are doing well post-HSCT. Mortality was recorded in 210 children (75.8%).ConclusionWe document an exponential rise in number of cases diagnosed to have SCID over the last 10 years, probably as a result of increasing awareness and improvement in diagnostic facilities at various centers in India. We suspect that these numbers are just the tip of the iceberg. Majority of patients with SCID in India are probably not being recognized and diagnosed at present. Newborn screening for SCID is the need of the hour. Easy access to pediatric HSCT services would ensure that these patients are offered HSCT at an early age.

Mendelian Susceptibility to Mycobacterial diseases (MSMD) are a group of innate immune defects with more than 17 genes and 32 clinical phenotypes identified. Defects in the IFN-γ mediated immunity lead to an increased susceptibility to intracellular pathogens like mycobacteria including attenuated Mycobacterium bovis-Bacillus Calmette-Guérin (BCG) vaccine strains and non-tuberculous environmental mycobacteria (NTM), Salmonella, fungi, parasites like Leishmania and some viruses, in otherwise healthy individuals. Mutations in the IL12RB1 gene are the commonest genetic defects identified. This retrospective study reports the clinical, immunological, and molecular characteristics of a cohort of 55 MSMD patients from 10 centers across India. Mycobacterial infection was confirmed by GeneXpert, Histopathology, and acid fast bacilli staining. Immunological workup included lymphocyte subset analysis, Nitro blue tetrazolium (NBT) test, immunoglobulin levels, and flow-cytometric evaluation of the IFN-γ mediated immunity. Genetic analysis was done by next generation sequencing (NGS). Disseminated BCG-osis was the commonest presenting manifestation (82%) with a median age of presentation of 6 months due to the practice of BCG vaccination at birth. This was followed by infection with Salmonella and non-typhi Salmonella (13%), Cytomegalovirus (CMV) (11%), Candida (7%), NTM (4%), and Histoplasma (2%). Thirty-six percent of patients in cohort were infected by more than one organism. This study is the largest cohort of MSMD patients reported from India to the best of our knowledge and we highlight the importance of work up for IL-12/IL-23/ISG15/IFN-γ circuit in all patients with BCG-osis and suspected MSMD irrespective of age.

Cytomegalovirus (CMV) infection remains an important cause of morbidity and mortality following allogeneic stem cell transplantation (SCT). We wanted to study if the high sero-prevalence seen in our population translated into a high incidence of CMV infection following SCT. This is a retrospective analysis of patients who underwent allogeneic SCT between January 2008 and December 2012 at our centre. 475 patients underwent allogeneic SCT for malignant (46.5%) and non-malignant (53.5%) haematological disorders. 463 (97.4%) SCT recipients and 403 (84.8%) SCT donors were IgG seropositive for CMV. CMV reactivation within 100 days post SCT was seen in 174 (36.6%) at a median of 41 days (range 10-100) post SCT. Ganciclovir was used in 166 patients (95.4%) for a mean duration of 16 days (range 5-32). 157 patients (90%) responded to therapy. Sixty-six patients (42.3%) had secondary reactivation of the virus. Use of a male donor (p = 0.000), donor and recipient age [ 15 (p = 0.005 and 0.000), unrelated donor (p = 0.000), degree of HLA mismatch (p = 0.000), occurrence of acute GVHD (p = 0.000) and steroid refractory acute GVHD (p = 0.026) were identified as risk factors for CMV reactivation while early neutrophil recovery (\ 15 days) was found to be protective (p = 0.004). On multivariate analysis, male donor (p = 0.042), degree of HLA mismatch (p = 0.006), the occurrence of acute GVHD (p = 0.000) and steroid refractory acute GVHD (p = 0.031) continued to remain significant. 5-year overall survival was significantly better in patients without CMV reactivation compared to those who developed reactivation of CMV (68.9 ± 3.7 vs 58.2 ± 4.9% p = 0.004). The incidence of CMV infection does not seem to be higher despite a high sero-prevalence of CMV. However, patients who developed CMV infection post SCT had inferior outcomes.