An alternative procedure to leukapheresis for peripheral hematopoietic progenitor cell collection in very-low-weight children: A single pediatric center experience.

BACKGROUND: PBSC collection using a blood cell separator in very low weight patients can be frequently complicated by severe adverse effects and technical difficulties. MATERIAL AND METHODS: From March 2013 to January 2017, 14 PBSC collections were performed in 12 children weighing less than 10 kg, affected by different solid tumours. PBSC collection was performed with a "homemade" aseptically assembled circuit. The circuit is composed by a 150 mL collection bag connected with a 4 stopcock ramp, perfused with ACD. This circuit allows collection of a specific total blood amount from CVC, depending on CD34+ /kg target. RESULTS: Mean CD34+ cell performance per collection was 9.3 × 106 /kg. Tolerance to the procedure was very good as none of the patients experienced complications, with the exception of a patient who showed mild cyanosis and pallor after collection. Moreover, no bleeding or thrombotic complications have been observed. To date, 16 PBSC reinfusions have been performed in 7 children with a mean CD34+ cells viability of 98.1% ± 2.7 and mean WBC viability of 57% ± 10. Cell recovery after thawing was 87% ± 10.8. A rapid graft intake for both neutrophils and platelets, between day 7 and 20 after reinfusion was observed. DISCUSSION: The procedure of total blood collection without the use of a cell separator is feasible and allows a good PBSC collection without significant side effects in very low-weight children. Moreover, this method could represent a valid and safe alternative to leukapheresis in patients where classic procedure could be difficult to apply.

Genotype-phenotype study of familial haemophagocytic lymphohistiocytosis type 3.

BACKGROUND: Mutations of UNC13D are causative for familial haemophagocytic lymphohistiocytosis type 3 (FHL3; OMIM 608898). OBJECTIVE: To carry out a genotype-phenotype study of patients with FHL3. METHODS: A consortium of three countries pooled data on presenting features and mutations from individual patients with biallelic UNC13D mutations in a common database. RESULTS: 84 patients with FHL3 (median age 4.1 months) were reported from Florence, Italy (n=54), Hamburg, Germany (n=18), Stockholm, Sweden (n=12). Their ethnic origin was Caucasian (n=57), Turkish (n=10), Asian (n=7), Hispanic (n=4), African (n=3) (not reported (n=3)). Thrombocytopenia was present in 94%, splenomegaly in 96%, fever in 89%. The central nervous system (CNS) was involved in 49/81 (60%) patients versus 36% in patients with FHL2 (p=0.001). A combination of fever, splenomegaly, thrombocytopenia and hyperferritinaemia was present in 71%. CD107a expression, NK activity and Munc 13-4 protein expression were absent or reduced in all but one of the evaluated patients. 54 different mutations were observed, including 15 new ones: 19 missense, 14 deletions or insertions, 12 nonsense, nine splice errors. None was specific for ethnic groups. Patients with two disruptive mutations were younger than patients with two missense mutations (p<0.001), but older than comparable patients with FHL2 (p=0.001). CONCLUSION: UNC13D mutations are scattered over the gene. Ethnic-specific mutations were not identified. CNS involvement is more common than in FHL2; in patients with FHL3 and disruptive mutations, age at diagnosis is significantly higher than in FHL2. The combination of fever, splenomegaly, thrombocytopenia and hyperferritinaemia appears to be the most easily and frequently recognised clinical pattern and their association with defective granule release assay may herald FHL3.

Comparison of CryoMACS Freezing Bags with Maco Biotech Freezing-Ethinyl Vinyl Acetate Bags for Hematopoietic Progenitor Cells Cryopreservation Using a CD34+-Enriched Product.

Background: Hematopoietic progenitor cells (HPCs) cryopreservation have applications, especially in the autologous setting, allowing therapeutic use several years after collection. Cryopreservation aims to preserve the therapeutic properties of HPCs, and successful cryopreservation depends on several factors such as preservation procedures, biopreservation media, freezing rates, and thawing procedures. In this context, the choice of the freezing bag is critical as it provides mechanical protection during the freezing process. Since Maco Biotech Freezing-ethinyl vinyl acetate (EVA) Bags® are no longer available in our country, a comparative study was developed to verify bioequivalence with the Miltenyi CryoMACS® freezing bag. Methods: In this study, a CD34+-enriched product was used to better reproduce HPC apheresis. Freezing bags were filled with the same volume, cryopreserved with controlled rate freezing, and stored in the vapor phase of liquid nitrogen for at least 6 months. After thawing, all bags were tested for integrity and sterility using a microbial challenge. In addition, a comparison was developed by evaluating recovery of white blood cells, mononuclear cells, lymphocytes, and CD34+ cells. Results: No significant differences between the two manufacturers' bags have been observed in terms of the evaluated parameters. Data were confirmed, even comparing bags according to filling volume. Data presented in this study support the conclusion that CryoMACS freezing bags are bioequivalent to Maco Biotech Freezing-EVA Bags for HPC cryopreservation.

Human platelet lysate in mesenchymal stromal cell expansion according to a GMP grade protocol: a cell factory experience.

BACKGROUND: The use of platelet lysate (PL) for the ex-vivo expansion of mesenchymal stromal/stem cells (MSCs) was initially proposed by Doucet et al. in 2005, as an alternative to animal serum. Moreover, regulatory authorities discourage the use of fetal bovine serum (FBS) or other animal derivatives, to avoid risk of zoonoses and xenogeneic immune reactions. Even if many studies investigated PL composition, there still are some open issues related to its use in ex-vivo MSC expansion, especially according to good manufacturing practice (GMP) grade protocols. METHODS: As an authorized cell factory, we report our experience using standardized PL produced by Azienda Ospedaliero Universitaria Meyer Transfusion Service for MSC expansion according to a GMP grade clinical protocol. As suggested by other authors, we performed an in-vitro test on MSCs versus MSCs cultured with FBS that still represents the best way to test PL batches. We compared 12 MSC batches cultured with DMEM 5% PL with similar batches cultured with DMEM 10% FBS, focusing on the MSC proliferation rate, MSC surface marker expression, MSC immunomodulatory and differentiation potential, and finally MSC relative telomere length. RESULTS: Results confirmed the literature data as PL increases cell proliferation without affecting the MSC immunophenotype, immunomodulatory potential, differentiation potential and relative telomere length. CONCLUSIONS: PL can be considered a safe alternative to FBS for ex-vivo expansion of MSC according to a GMP grade protocol. Our experience confirms the literature data: a large number of MSCs for clinical applications can be obtained by expansion with PL, without affecting the MSC main features. Our experience underlines the benefits of a close collaboration between the PL producers (transfusion service) and the end users (cell factory) in a synergy of skills and experiences that can lead to standardized PL production.

Neuromyelitis optica, atypical hemophagocytic lymphohistiocytosis and heterozygous perforin A91V mutation.

Neuromyelitis optica is an autoimmune demyelinating inflammatory disease characterized by optic neuritis and myelitis with anti-aquaporin 4 antibodies. Hemophagocytic lymphohistiocytosis is a severe systemic inflammatory syndrome that can present in a genetic primary form or secondarily to infective, neoplastic or autoimmune diseases. Our case discusses the first reported case of atypical late-onset hemophagocytic lymphohistiocytosis in a patient with neuromyelitis optica, with multiple triggering factors and carrying the common A91V hypomorphic perforin mutation, that blurs the distinction between primary and secondary forms.

The novel synthetic immune response modifier R-848 (Resiquimod) shifts human allergen-specific CD4+ TH2 lymphocytes into IFN-gamma-producing cells.

BACKGROUND: In experimental models, imidazoquinolines exhibit several immunomodulatory activities via Toll-like receptor signaling on cells of the innate immunity. OBJECTIVE: The aim of our study was to investigate whether R-848 (Resiquimod), a small-molecular-weight synthetic compound belonging to the imidazoquinoline family and known for its ability to substantially delay the onset of recurrent genital herpes lesions in both animals and human beings, could influence, at least in vitro, the cytokine production profile of human hapten- or allergen-specific T cells. METHODS: Ampicillin- and Der p 1-specific T-cell lines were derived from peripheral blood of allergic donors in the absence or presence of R-848 and assessed by flow cytometry at the single-cell level for their ability to produce IL-4 and/or IFN-gamma. RESULTS: R-848 induced both hapten- and allergen-specific circulating T cells, including T(H)2 effectors, to produce IFN-gamma and even to lose the ability to produce IL-4, thus shifting their phenotype of cytokine production to a type 0 (T(H)0) or even T(H)1 profile. This effect was associated with an increase in the production of IL-12, IFN-alpha, IL-18, TNF-alpha, IL-10, and IL-15 by CD14(+) cells, as well as an increase in the proportions of IFN-gamma-producing CD3(-)CD16(+) (natural killer) cells. CONCLUSIONS: These results suggest that R-848, and probably other imidazoquinolines, might be used as adjuvants in view of novel allergen-specific immunotherapeutic regimens for the treatment of allergic disorders.