Single Cord Blood Transplantation Combined With An HLA Mismatched Third Party Donor For High-Risk Hematological Patients With HIV Infection

The safety and usefulness of unrelated umbilical cord blood (CB) stem cell transplantation (SCT) in patients candidates for allogeneic SCT and HIV infection is unknown. Single CB with the co-infusion of CD34+ cells from a third party HLA-mismatched donor (TPD), or Haplo-cord SCT, has shown to reduce the period of post-transplant neutropenia and related early complications associated with single CB transplantation. This platform could potentially reduce the risk of early infections in this particular group of patients. On the other hand, the use of a cell source homozygous for the CCR5 delta32 allele mutation, which confers high resistance against HIV-1 acquisition, is of particular interest in HIV+ patients.

We report here on the first two patients with HIV infection and high-risk haematological malignancies who underwent haplo-cord SCT in two different centers: (Case 1) a 53 year-old male patient with high-risk MDS; (Case 2) a 34 year-old male with Burkitt lymphoma in CR2. Both CB transplants were performed using the haplo-cord platform with the co-infusion of mobilized and selected CD34+ cells from a TPD. Conditioning regimen were myeloablative in both cases. Case 1 had the additional potential benefit from the use of a CB unit with the homozygous CCR5delta32 mutation. Both cases achieved neutrophil and platelet engraftment similarly to previous haplo-cord SCT performed in HIV negative patients, as well as full CB chimerism. However, case 1 developed beside a severe lung infection, relapse of the underlying malignancy 2 months after SCT and died consequently. Case 2 presented one episode of bacterial sepsis with good response to antibiotics, and one episode of CMV reactivation controlled with valgancyclovir. Thirteen months after SCT, this patient is alive and in CR. Extensive analyses of viral and immunological compartments were performed showing the early viral dynamics in both patients.

CB SCT is feasible in patients eligible for allogeneic SCT and HIV infection. The haplo-cord strategy with the co-infusion of auxiliary cells from a TPD seems to offer a fast neutrophil engraftment similarly to HIV negative patients. Therefore, this strategy should be considered in patients with HIV infection and indication for allogeneic SCT, whenever CB is the source of choice and especially if a CCR5 mutated unit is available.

Kuball:Miltenyi: GMP product development Other.