Ngwube, Alexander

Sickle cell disease (SCD) is a chronic hematologic disorder which causes progressive cerebral arteriopathy beginning in childhood. As a result, arterial ischemic stroke is a major cause of morbidity and mortality in SCD, and SCD is a leading cause of childhood stroke worldwide. Allogenic hematopoietic stem cell transplant (HSCT) may be curative for individuals with SCD. Long-term outcomes and effects are currently being studied. In this report, we describe a child with SCD who presented with arterial ischemic stroke at 6 years of age and was found to have a severe form of cerebral large vessel arteriopathy by catheter-directed angiography. The patient initially underwent revascularization surgery by indirect superficial temporal artery to middle cerebral artery bypass, and 1 year later, he underwent curative HSCT. Approximately 3 years after HSCT, repeat catheter-directed angiography revealed a striking reversal of cerebral large vessel arteriopathy. This article reveals a previously unrecognized and potentially beneficial effect of HSCT that may ameliorate cerebral large vessel arteriopathy and improve cerebrovascular health for children with SCD.

AbstractBackgroundSirolimus is an immunosuppressive agent used in organ rejection prophylaxis in solid‐organ transplantation, graft‐vs‐host disease prophylaxis in hematopoietic stem cell transplantation, and as an immune modulator for patients with lymphangioleiomyomatosis and vascular malformations. Sirolimus has a narrow therapeutic index with potential severe side effects, including hypertension, hepatotoxicity, nephrotoxicity, and neurotoxicity.Case ReportWe report a case of a 19‐year‐old woman with severe sickle cell disease who underwent a matched unrelated hematopoietic stem cell transplantation, whose course was complicated by sirolimus toxicity. This case was challenging because sirolimus has no specific antidote, is largely bound to red blood cells (RBCs), has a high distribution volume, and cannot be removed by dialysis or plasmapheresis.ResultDue to the concern for toxicity, we looked into possibilities for rapid sirolimus clearance using automated RBC exchange. The treatment was effective in decreasing blood sirolimus levels within the therapeutic ranges.ConclusionThe use of RBC exchange is potentially safe and effective in the management of a case of sirolimus toxicity.

AbstractIntroductionThe effects of RIC for HSCT on male fertility remain unknown. We investigated spermatogenesis and gonadal hormonal status among adolescent male patients who received RIC HSCT for non‐malignant diseases.Patients and MethodsPatients with non‐malignant disease who had undergone a RIC HSCT were recruited and evaluated for spermatogenesis via semen analysis and gonadal hormonal function via serum hormone levels. Those who had received prior chemotherapy or radiation were excluded from the study. We reviewed the charts to record demographic factors, conditioning regimen and complications during and after transplant.ResultsFive patients were enrolled. The median age at the time of transplant was 15 years (range, 11‐19 years), and the median time between bone marrow transplant and semen analysis was 5 years (range, 3‐11 years). Median age of patients was 20 years (range, 18‐25 years) at the time of the study. Serum FSH and LH levels were elevated in four patients, and inhibin B levels were low for age in three patients. Semen analysis showed two patients had azoospermia, and the remaining three patients showed severe oligozoospermia. Normal morphology and motility were seen in only one patient.ConclusionThis case series suggests that RIC transplants may be associated with impaired spermatogenesis and sequential follow‐up is necessary given the potential for either permanent impairment or delayed recovery. Further larger studies are needed to confirm these findings.

BACKGROUND After hematopoietic stem cell transplantation (HSCT) autoimmune hemolytic anemia (AIHA) is a known and fairly common complication. It is often refractory to conventional therapies including corticosteroids, intravenous immunoglobulin, splenectomy, and the more recently described use of monoclonal antibodies. The high morbidity associated with these severe persistent cases elucidates the gaps in alternative therapies available for treatment. STUDY DESIGN AND METHODS We described the successful use of abatacept for severe refractory AIHA after HSCT in three patients. RESULTS Three pediatric patients with refractory AIHA after allogeneic stem cell transplantation were observed to be unresponsive to multitude immunosuppressive therapies, resulting in persistent transfusion dependency. Treatment with abatacept, a fusion protein that inhibits T‐cell activation by binding to CD80/CD86 on antigen‐presenting cells (APCs), thus blocking the required CD28 interaction between APCs and T cells, resulted in the resolution of hemolysis. CONCLUSION Abatacept may provide significant clinical benefit in the management of AIHA after HSCT.