Transplantation of Hematopoietic Stem Cells for Primary Immunodeficiencies in Brazil: Challenges in Treating Rare Diseases in Developing Countries.

The results of hematopoietic stem cell transplant (HSCT) for primary immunodeficiency diseases (PID) have been improving over time. Unfortunately, developing countries do not experience the same results. This first report of Brazilian experience of HSCT for PID describes the development and results in the field. We included data from transplants in 221 patients, performed at 11 centers which participated in the Brazilian collaborative group, from July 1990 to December 2015. The majority of transplants were concentrated in one center (n = 123). The median age at HSCT was 22 months, and the most common diseases were severe combined immunodeficiency (SCID) (n = 67) and Wiskott-Aldrich syndrome (WAS) (n = 67). Only 15 patients received unconditioned transplants. Cumulative incidence of GVHD grades II to IV was 23%, and GVHD grades III to IV was 10%. The 5-year overall survival was 71.6%. WAS patients had better survival compared to other diseases. Most deaths (n = 53) occurred in the first year after transplantation mainly due to infection (55%) and GVHD (13%). Although transplant for PID patients in Brazil has evolved since its beginning, we still face some challenges like delayed diagnosis and referral, severe infections before transplant, a limited number of transplant centers with expertise, and resources for more advanced techniques. Measures like newborn screening for SCID may hasten the diagnosis and ameliorate patients' conditions at the moment of transplant.

Adherence and immune response to revaccination following hematopoietic stem cell transplantation at a pediatric onco-hematology reference center.

BACKGROUND: Revaccination after hematopoietic stem cell transplantation (HSCT) is necessary to compensate for the loss of immunological memory. The aims of this study were to evaluate the adherence to revaccination schedule and the humoral immune response to different vaccine antigens in HSCT pediatric and young adult patients. METHODS: Patients submitted to HSCT for over 3 years were recruited. After written informed consent, a questionnaire was filled in, the vaccination card was analyzed, a blood sample was collected and tested by ELISA for diphtheria, Haemophilus influenzae type b (Hib), hepatitis A, hepatitis B, tetanus, measles, rubella, and varicella antibodies. RESULTS: Sixty-three patients (mean age at HSCT, 10.7 years) were evaluated. Forty-one (65%) were male; 34 (54%) had allogeneic and 29 (46%), autologous HSCT. Complete adherence to diphtheria revaccination was found in 79.4% patients and seropositivity was found in 92% of those who completed the revaccination schedule; for Hib, 68.3% adherence and 95.3% seropositivity were observed; for hepatitis A, 63.5% adherence and 92.5% seropositivity; for 3 doses of hepatitis B, 86.8% adherence and 79.2% seropositivity; for tetanus, 79.4% adherence and 100% seropositivity; for measles and rubella, 17.5% adherence and 100% seropositivity; for varicella, 7.9% adherence and 100% seropositivity. The existence of a Vaccination Center for Special Immunobiologicals in patients' municipality was positively associated with completed vaccine schedule; on the other hand, chronic GVHD was negatively associated with revaccination adherence. CONCLUSION: Hematopoietic stem cell transplantation patients showed good seropositivity rates after complete vaccination schedule. However, a low coverage rate was observed for live attenuated antigens.

Rapid, low-cost MR imaging protocol to document central nervous system and sinus abnormalities prior to pediatric hematopoietic stem cell transplantation.

Patients undergoing bone marrow transplant (BMT) are at risk for infectious complications, including those of the sinus. Central nervous system (CNS) abnormalities related to the chemotherapy or radiation that the patient received for the treatment of underlying malignancy or to transplant-related effects are also commonly seen. The only effective way to differentiate pre- and post-transplant causes is to have a baseline evaluation prior to the admission for transplant. The current method used to evaluate these patients is head CT. However, CT is not accurate to demonstrate CNS abnormalities and exposes the patient to radiation. MRI, despite better sensitivity for white matter abnormalities, has not been routinely used because of the higher cost and longer duration of the exam. Therefore, we designed a fast, low-cost and radiation-free MRI-based protocol to simultaneously evaluate sinus and brain abnormalities.