Stem Cell Transplantation: Impact of High Efficiency Particulate Air (HEPA) vs. Non-HEPA BMT Unit on Transplant Outcome: A Single Centre Experience from India.
Authors: Nair Velu , Sharma Ajay , Mishra Deepak K. , Chopra Gurvinder S. , Kotwal J. , Agarwal Mohan B. , Bhandari N. K. , Rai Ramji 
Published: April 2020

Abstract
The stem cell transplantation( SCT) has become a standard of care in certain hematological disorders including malignant and non malignant diseases but its availability remains limited to a small portion of population especially in developing countries. We started stem cell transplantation program in our centre since 1998. Initially it was in a room with basic facilities of an aseptic area but without HEPA filters. It was in 2002 only that a proper unit with HEPA filters came up. We present retrospective data of 70 (24 females) patients who have undergone stem cell transplantation till June 2005. The mean age was 28 years (range: 3–47). The indications for SCT were CML: 24, AML: 10, Multiple myeloma: 12, Thal major: 8, NHL: 8, MDS:2, ALL:3, CLL:1 and Aplastic anemia :2. Thirty of these underwent autologous SCT. Twenty eight patients who underwent transplantation prior to 2002, before HEPA filter unit came up, had parameters comparable to the patients who underwent transplantation in HEPA filter units. Allogeneic recipients received stem cells from HLA matched siblings with standard Busulfan-Cyclophosphamide conditioning protocols and GVHD prophylaxis using methorexate and ciclosporin. The conditioning for thalassemia and Aplastic anemia included anti-thymocyte globulin. The median cell dose in pre HEPA filter group was 7.63x 108/Kg and for post HEPA group it was 4.94 x108/Kg. The results showed marked differences in the outcome of transplant parameters. Neutrophil and platelet engraftment occurred at similar times in two groups as was the incidence of veno-occlusive disease. The overall incidence of grade III and IV acute Graft versus host disease (Ac GVHD) was 40% in first group and 13% in second group.(54% vs.8% skin and46% Vs.15% GIT ). Acute severe GVHD (grade III and IV) resulted in death of 7 patients in first group and 2 patients in second group. Eight patients (52%) died of infections in first group while only 2 patients had infection with fatal outcome in second group. Four patients developed interstitial pneumonitis (IP) in first group while only one patient developed this complication in second group which proved fatal. Chronic GVHD was encountered in one patient in each group. One important factor which was consistently seen in post HEPA filter patient group was the reduced duration of hospitalization in BMT unit as well as step down unit (3 weeks Vs 6 weeks). Although the number of transplants is small but it can be well inferred that HEPA filters have definite impact on improved transplant outcome in our patients. While results of stem cell transplantation are likely to improve with time due to better protocols and patient selection. But an investment in certain facilities like HEPA filters, laminar air flow and other hygienic measures is essential for a successful transplantation especially in a third world countries where environmental pollution can be a big hazard. The cost factor is an important consideration in a developing country like India, but certain baseline parameters will have to be maintained even in SCT centers with limited funds. Low cost transplantation centers will have to cater for basic necessary equipment in order to improve the transplant outcome. It will surely be cost effective in view of less morbidity and mortality.