PB2351 ALLOGENEIC TRANSPLANT EXPERIENCE IN ADULT PATIENTS WITH PRIMARY IMMUNODEFICIENCY
Authors: M. Kurt Yuksel, Z. Narli Ozdemir, F. O. Ardeniz, D. Cagdas Ayvaz, N. D. Altıntas, O. Kumbasar, A. Azap, G. Cengiz Seval, S. Civriz Bozdag, S. K. Toprak, P. Topcuoglu, G. Gurman, A. Ikinciogulları
Journal: HemaSphere (2019)

Background: Primary immunodeficiencies (PIDs) are associated with recurrent infections with multipl microbial agents. The prevelance of PID diseases are high in Turkey, where consanguineous marriages are common. In primary immunodeficiencies, allogeneic hematopoietic stem cell transplantation (allo‐HCST) is mostly performed during childhood. Due to lack of experience and previous poor results, there is debate about the optimal timing and use of allo‐HCST in adults. Aims: The aim of this presentation is to report the results of allogeneic HSCT from matched unrelated donor (MUD) in four adult patients with diagnosis of PID. Methods: The results of allo‐HCST of 4 adult patients (3 male and 1 female) with diagnosis of PID were evaluated retrospectively. Median age was 22 years. Patients had intensive history of infection such as bronchiectasis, penile HPV, tuberculosis and suppurative soft tissue infection of the head and neck. Demographic characteristics of patients, conditioning regimens, donor characteristics, stem cell source and amount, graft versus disease (GvHH) prophylaxis are given in table 1.The busulfan dose was kept in the effective range by calculating the area under the curve.They were ordered prophylactic intravenous immunoglobulin (IVIg) 0.4 g/kg weekly. Viral loads for EBV and CMV were weekly screened by PCR. Results: Median follow‐up time is 10 months (range: 5‐13 months). Neutrophil and platelet engraftment took place on median days 15 (range:11‐17 days) and 12.5 (range.8‐20), respectively. Patient no 1 lived grade 4 gastrointestinal truct GvHD, grade 2 lung GvHD and grade 2 skin GvHD. Grade 4 gastrointestinal truct and grade 3 liver GvHD were occured in patient no 2. Both of them were treated with ruxolitinib, mesenchymal stem cell and extracorporeal photopheresis according to clinical picture of the patients. The donor chimerism on day 90 was found to be median 99% (range:98% &gt; 100%) for three patients. Patient no 3 had lost donor‐type chimerism at the enf of second months. Patient no 1 and no 2 needed for admission to intensive care unit due to pneumonia and gram negative sepsis, respectively. Patient no 2 died due to gram negative septic shock in the 11th month of allo‐HCST. Unlike others, EBV DNA titer increased to 1978 copy / ml in patient no 2. Without treatment, the EBV DNA titer gradually decreased and reached a limit of &lt;153 copies / ml. Summary/Conclusion: The timing of HSCT for PID diseases in adulthood is considered to be rather late. However, HSCT yet offers a curative potential without causing a serious toxicity due to conditioning regimens and an increased rate of infections during neutropenic period. Patients with intensive history of infection require strong cooperation with intensive care units, infections and chest diseases in the transplantation and post‐transplant follow‐up periods. These patients should be strictly followed‐up for the risk of acute/chronic GvHD. The long term effects of immunosupressive treatment among these patients is also a serious concern. image