Immunoglobulin and T cell receptor gene high-throughput sequencing quantifies minimal residual disease in acute lymphoblastic leukemia and predicts post-transplantation relapse and survival.

Minimal residual disease (MRD) quantification is an important predictor of outcome after treatment for acute lymphoblastic leukemia (ALL). Bone marrow ALL burden ≥ 10(-4) after induction predicts subsequent relapse. Likewise, MRD ≥ 10(-4) in bone marrow before initiation of conditioning for allogeneic (allo) hematopoietic cell transplantation (HCT) predicts transplantation failure. Current methods for MRD quantification in ALL are not sufficiently sensitive for use with peripheral blood specimens and have not been broadly implemented in the management of adults with ALL. Consensus-primed immunoglobulin (Ig), T cell receptor (TCR) amplification and high-throughput sequencing (HTS) permit use of a standardized algorithm for all patients and can detect leukemia at 10(-6) or lower. We applied the LymphoSIGHT HTS platform (Sequenta Inc., South San Francisco, CA) to quantification of MRD in 237 samples from 29 adult B cell ALL patients before and after allo-HCT. Using primers for the IGH-VDJ, IGH-DJ, IGK, TCRB, TCRD, and TCRG loci, MRD could be quantified in 93% of patients. Leukemia-associated clonotypes at these loci were identified in 52%, 28%, 10%, 35%, 28%, and 41% of patients, respectively. MRD ≥ 10(-4) before HCT conditioning predicted post-HCT relapse (hazard ratio [HR], 7.7; 95% confidence interval [CI], 2.0 to 30; P = .003). In post-HCT blood samples, MRD ≥10(-6) had 100% positive predictive value for relapse with median lead time of 89 days (HR, 14; 95% CI, 4.7 to 44, P < .0001). The use of HTS-based MRD quantification in adults with ALL offers a standardized approach with sufficient sensitivity to quantify leukemia MRD in peripheral blood. Use of this approach may identify a window for clinical intervention before overt relapse.

Successful surgical and medical treatment of rhizopus osteomyelitis following hematopoietic cell transplantation.

Mucormycosis has been reported in otherwise healthy individuals; however, it is primarily seen in immunocompromised patients, such as those with diabetes mellitus, malignancy, or chronic graft-versus-host disease, and has a high mortality rate. Because most cases of mucormycosis are associated with contiguous rhinocerebral infection, only 5 cases of isolated musculoskeletal Rhizopus infection have been reported in the literature. One patient underwent hematopoietic cell transplant, which resulted in a fatal outcome.This article describes the successful treatment of isolated Rhizopus osteomyelitis in a patient who underwent hematopoietic cell transplant using a combined surgical and medical approach. A 33-year-old woman with pre-B cell acute lymphoblastic leukemia underwent hematopoietic cell transplant with few complications but developed chronic graft-versus-host disease 8 months posttransplant. She was treated with high-dose steroids for 6 weeks before she was admitted for severe right tibial pain in the absence of trauma. Early detection, aggressive therapies, and a multidisciplinary surgical and medical team allowed for the microbiologically confirmed resolution of the infection. Treatment included multiagent antimicrobial therapy with amphotericin B, daptomycin, and ertapenem. Several surgical irrigation and debridement procedures were also performed, with the eventual placement of amphotericin-impregnated polymethylmethacrylate cement beads and small fragment titanium screws. The patient continued taking postoperative antifungal treatment for 7 months after discharge. Six months following the discontinuation of antifungal therapy, the team's multidisciplinary approach achieved a continued resolution of the patient's infection and a return to a fully ambulatory and radiographically proven recovery without limb loss.