Safety and efficacy of autologous hematopoietic stem-cell transplantation following natalizumab discontinuation in aggressive multiple sclerosis.

BACKGROUND AND PURPOSE: Natalizumab (NTZ) is a highly effective treatment for relapsing-remitting multiple sclerosis (MS), but its withdrawal is often followed by disease reactivation or rebound, even if other disease-modifying treatments (DMTs) are administered. In this study, for the first time, the safety and efficacy of autologous hematopoietic stem-cell transplantation (aHSCT) performed following NTZ discontinuation were retrospectively compared with conventional DMTs. METHODS: Patients with relapsing-remitting MS treated with NTZ who discontinued the drug after at least six administrations and with at least 6 months of follow-up were included. Patients underwent aHSCT after a minimum of 6 months following NTZ withdrawal, receiving meanwhile cyclophosphamide or corticosteroids, or other DMTs approved for MS (control group) after an adequate wash-out period. Both hematological and neurological follow-up were assessed according to standard policies. RESULTS: A total of 52 patients were included, 11 who received aHSCT and 41 who received DMTs. Baseline clinical and demographic characteristics were similar between the two groups. No fatality or life-threatening complications, including progressive multifocal leukoencephalopathy, were observed. At 3 years following NTZ discontinuation, no evidence of disease activity was reported in 54.5% of the patients in the aHSCT group compared with 11.5% of those in the DMT group (P = 0.0212). Disease reactivation in the patients with aHSCT was observed only during wash-out/bridging therapy and 100% of the cases were free from disease activity after aHSCT. CONCLUSIONS: These data suggest that an aggressive therapy should be established after NTZ with the shortest possible wash-out period. aHSCT after 6 months from NTZ withdrawal appears to be safe.

Microsatellite instability as biomarker for risk of multiple primary malignancies of the upper aerodigestive tract.

Head and neck cancer (HNC) patients are at high risk of developing second primary tumors of the upper aerodigestive tract and this is a chief cause of death. Genomic instability reflecting the propensity and the susceptibility of the genome to acquire multiple alterations is considered a driving force behind multiple carcinogenesis and the alterations of the length of single repetitive genomic sequences or microsatellite instability (MI), implicating impaired DNA repair mechanisms, and could be a sensitive marker for assessing genomic instability in multiple HNC. To investigate whether a genetic defect(s) involving the mismatch repair system constitutes a risk factor in patients with multiple head and neck cancer, we examined replication errors (RER) at 10 microsatellite loci in 21 primary and 5 second primary cancers in 21 patients with multiple malignancies of the upper aerodigestive tract, in comparison with match-paired primary HNC from patients without multiple malignancies. A RER+ phenotype (alterations at > or =2 loci) was observed at 10 microsatellite alterations on chromosomes 2, 3, 11, 17 in at least one tumor from 15 out of 21 (71.5%) patients with multiple primary cancers but only in 11 tumors from 40 (27.5%) HNC patients with single cancer (P=0.001). A RER+ phenotype was also associated with a positive familial cancer history (P=0.046). Our results suggest that a genetic instability may play an important role in the pathogenesis of multiple primary cancers and that testing for MI in a primary HNC may be useful in detecting patients with high risk for developing multiple malignancies of the upper aerodigestive tract.