Benedetta Mazzi

Intra-arterial transplantation of HLA-matched donor mesoangioblasts in Duchenne muscular dystrophy

Intra‐arterial transplantation of mesoangioblasts proved safe and partially efficacious in preclinical models of muscular dystrophy. We now report the first‐in‐human, exploratory, non‐randomized open‐label phase I–IIa clinical trial of intra‐arterial HLA‐matched donor cell transplantation in 5 Duchenne patients. We administered escalating doses of donor‐derived mesoangioblasts in limb arteries under immunosuppressive therapy (tacrolimus). Four consecutive infusions were performed at 2‐month intervals, preceded and followed by clinical, laboratory, and muscular MRI analyses. Two months after the last infusion, a muscle biopsy was performed. Safety was the primary endpoint. The study was relatively safe: One patient developed a thalamic stroke with no clinical consequences and whose correlation with mesoangioblast infusion remained unclear. MRI documented the progression of the disease in 4/5 patients. Functional measures were transiently stabilized in 2/3 ambulant patients, but no functional improvements were observed. Low level of donor DNA was detected in muscle biopsies of 4/5 patients and donor‐derived dystrophin in 1. Intra‐arterial transplantation of donor mesoangioblasts in human proved to be feasible and relatively safe. Future implementation of the protocol, together with a younger age of patients, will be needed to approach efficacy.

Genomic loss of patient-specific HLA in acute myeloid leukemia relapse after well-matched unrelated donor HSCT

To the editor:nnAllogeneic hematopoietic stem cell transplantation (HSCT) can grant long-term control and cure of acute myeloid leukemia (AML) thanks to the antitumor effect of the transplanted immune system. Still, relapse remains an open issue: in the haploidentical setting, we and others

Sequencing of a new HLA-A*32 subtype (A*3202)

A healthy Caucasian donor (donor MP) enrolled in the Italian National Bone Marrow Registry (IBMDR) was typed as HLA A3/A32, B15/B38, Cw4/by standard serology. Molecular typing of theHLA-A locus was routinely performed using a previously described polymerase chain reaction (PCR) sequence-specific oligonucleotide probe (SSOP) approach (Oh et al. 1992; Benazzi et al. 1995). This analysis revealed an unexpected hybridization pattern forA*32 involving probes derived from the region around codons 151 and 156 of the L2 domain. cDNA was prepared by reverse transcription of mRNA extracted from peripheral blood lymphocytes of donor MP. The full-lengthA*32 coding region was PCR-amplified by use of a primer pair suitable for amplification of A*32 but not of A*03 genes. Primers were a generous gift of S. Y. Yang. The 1.1 kilobase PCR products from two independent PCR were subcloned into pBluescript and sequenced on both strands by the Sanger dideoxy chain termination method (Sanger et al. 1977). The new A*32 allele, now referred to asA*3202, was shown to differ fromA*3201by three nucleotide substitutions in exon 3. Base pair (bp) 182 in exon 3 was changed from G in A*3201 to A in A*3202 and bps 196/197 were changed from TT in A*3201to CA in A*3202 (Fig. 1A). This changed the predicted amino acid sequence from Arg ( A*3201) to His (A*3202) at codon 151 and from Leu ( A*3201) to Gln (A*3202) at codon 156 of the L2 domain (Fig. 1B). The combination 151His/156Gln is also found in someA*24 subtypes, inA*3202, and in A*0212 (Arnett et al. 1995).A*3202 may have arisen by gene conversion of A*3201 with one of these alleles. In order to assess the frequency of A*3202 in Caucasians from Northern Italy, sixty-eight additional samples from unrelated, healthy individuals enrolled in the IBMDR and typed as HLA-A32 by standard serology were screened for the presence of A*3202by PCR-SSOP typing. A*3202was found in two additional samples. Therefore, the frequency of A*3202 in A*32+ Caucasians from Northern Italy amounts to 3/69 = 4.34%. TheA*32 allele has been reported to have a frequency of 5.6% in Italian Caucasians (Imanishi et al. 1991). Therefore, the estimated overall frequency ofA*3202 in Italians is 0.24%. Interestingly, two of the three individuals carrying the A*3202gene came from the region of Valtellina, while only twelve of the sixty-nineA*32+ donors tested came from this region. This raises the possibility that A*3202 might occur with increased frequency in the population of Valtellina which, as judged by the highly restricted number of family names, is relatively inbred, although the exact extent of any inbreeding is unknown. The nucleotide sequence data reported in this paper have been submitted to the EMBL nucleotide sequence database and have been assigned the accession number X97120. The name A*3202 was officially assigned by the WHO Nomenclature Committee in June 1996. This follows the agreed policy that, subject to the conditions stated in the most recent Nomenclature Report (Bodmer et al. 1995), names will be assigned to new sequences as they are identified. Lists of such new names will be published in the following WHO Nomenclature Report

A new tool for rapid and reliable diagnosis of HLA loss relapses after HSCT

Institute for Experimental Cellular Therapy, University Hospital Essen, Essen, Germany; Unit of Immunogenetics, Leukemia Genomics and Immunobiology, IRCCS San Raffaele Scientific Institute, Milano, Italy; GenDx, Utrecht, Netherlands; KimerDx, Utrecht, Netherlands; Department of Bone Marrow Transplantation, West German Cancer Center, University Hospital Essen, Germany; Hematology and Bone Marrow Transplantation Unit, IRCCS San Raffaele Scientific Institute, Milano, Italy; Vita-Salute San Raffaele University, Milano, Italy; German Cancer Consortium (DKTK), Heidelberg, Germany. * and § indicate equal contribution