Haploidentical transplantation is feasible and associated with reasonable outcomes despite major infective complications – a single center experience from India.

Abstract Purpose Haplo-identical stem cell transplant [HaploSCT] using post-transplant cyclophosphamide for GVHD prophylaxis is a reasonable therapeutic option for patients who do not have a matched sibling donor. Methods Between 2010 and June 2020, 257 patients underwent 269 Haplo transplants including 122 children. Indications included both malignant [56.8%] and non-malignant [43.2%] diseases. Conditioning regimens included both myeloablative [57.6%] and non-myeloablative regimens [42.4%]. Peripheral blood stem cells [PBSC] was the predominant graft source [96.2%]. Based on the disease risk index, patients were classified into early, intermediate and late stage disease. Results Engraftment was seen in 205 patients [76.2%] while 39 [14.4%] died prior to engraftment and 23 [8.6%] had primary graft failure. The cumulative incidence of grade II-IV acute graft versus host disease [GVHD] was 47.8% with a 23.9% incidence of grade III-IV aGVHD. Chronic GVHD was seen in 41.9% with a 15.4% incidence of extensive chronic GVHD. More than 90% had atleast 1 documented infection with a 44% incidence of bacterial, 71% viral and 38% fungal infection. The 2-year overall survival is 40.5 ± 3.2% with a higher survival among children [48.2 ± 3.4%] compared to adults [34.2 ± 4.1%]. Survival was poor with late-stage disease [23.6 ± 4.3%] compared to early [62.5 ± 7.5%] and intermediate stage [50.3 ± 4.3%]. Factors adversely affecting survival included older age of patient [p =0.007], late disease status [p = 0.000], non-myeloablative conditioning regimen [p = 0.003], bone marrow as graft source [p = 0.006], presence of acute GVHD [p = 0.069], primary graft failure [p = 0.000] and presence of a documented bacterial [p = 0.000] and fungal infection [p = 0.000]. On multivariate analysis, older age [p = 0.027], presence of acute GVHD [p=0.033], documented bacterial infection [p = 0.000], documented fungal infection [p = 0.000] and primary graft failure [p = 0.012] continued to remain significant. Conclusions Haplo-identical SCT offers a reasonable chance of cure for patients with both malignant and non-malignant hematological diseases. Strategies to reduce aGVHD and infection related mortality needs to be explored further.