High accuracy differentiating autoimmune pancreatitis from pancreatic ductal adenocarcinoma by immunoglobulin G glycosylation.

BACKGROUND: Misdiagnosis of autoimmune pancreatitis (AIP) as pancreatic cancer (PDAC) or vice versa can cause dismal patents' outcomes. Changes in IgG glycosylation are associated with cancers and autoimmune diseases. This study investigated the IgG glycosylation profiles as diagnostic and prognostic biomarkers in PDAC and AIP. METHODS: Serum IgG-glycosylation profiles from 86 AIP patients, 115 PDAC patients, and 57 controls were analyzed using liquid chromatography-electrospray ionization mass spectrometry. Classification and regression tree (CART) analysis was applied to build a decision tree for discriminating PDAC from AIP. The result was validated in an independent cohort. RESULTS: Compared with AIP patients and controls, PDAC patients had significantly higher agalactosylation, lower fucosylation, and sialylation of IgG1, a higher agalactosylation ratio of IgG1 and a higher agalactosylation ratio of IgG2. AIP patients had significantly higher fucosylation of IgG1 and a higher sialylation ratio of IgG subclasses 1, 2 and 4. Using the CART analysis of agalactosylation and sialylation ratios in the IgG to discriminate AIP from PDAC, the diagnostic accuracy of the glycan markers was 93.8% with 94.6% sensitivity and 92.9% specificity. There were no statistically significant difference of IgG-glycosylation profiles between diffuse type and focal type AIP. CONCLUSIONS: AIP and PDAC patients have distinct IgG-glycosylation profilings. IgG-glycosylation could different PDAC from AIP with high accuracy.

Human platelet concentrates: a source of solvent/detergent-treated highly enriched brain-derived neurotrophic factor.

BACKGROUND: Human blood platelets (PLTs) contain brain-derived neurotrophic factor (BDNF), a neurotrophin that binds to neurotrophic tropomyosin-related kinase B (TrkB) receptor on central nervous system cells. This binding promotes neural synaptic plasticity and memory and prevents neuronal degeneration. Alterations in BDNF homeostasis are associated with aging and are found in several neurodegenerative conditions such as Alzheimer's, Huntington's, and Parkinson's diseases and multiple sclerosis. We have developed PLT viral inactivation and chromatographic fractionation processes and decided here to identify fractions enriched in BDNF. STUDY DESIGN AND METHODS: PLT concentrates (PCs) were treated by solvent/detergent (S/D), extracted by oil, and subjected to fractionation (C18, sulfopropyl [SP]-Sepharose, diethylaminoethyl [DEAE]-Sepharose, or activated charcoal). BDNF and pro-BDNF were evaluated by enzyme-linked immunosorbent assay, and Western blot. TrkB was studied by Western blot. Tri-n-butyl phosphate (TnBP) was quantified by high-performance liquid chromatography, and Triton X-45 by gas chromatography. RESULTS: The mean BDNF content of 2.9 ± 0.7 ng/mL in PC was noted to increase to 56.2 ± 2.4 ng/mL after S/D treatment and remained stable during oil extraction. Approximately 70% of the BDNF content was recovered after C18 chromatography. BDNF did not bind to DEAE-Sepharose and was almost completely adsorbed by charcoal. Chromatography on SP-Sepharose yielded a highly enriched 13-kDa mature BDNF fraction that was more than 170-fold purified, with a mean of 137 ± 29.4 ng/mL and 82% chromatographic recovery, devoid of detectable TnBP and Triton X-45. Pro-BDNF and TrkB proteins were not detected in the PLT extracts. CONCLUSION: We obtained a S/D-treated, highly enriched mature PLT-derived BDNF fraction that could help unveil the pharmacokinetics, pharmacodynamic, and potential therapeutic applications of the BDNF neurotrophin.

Human blood-derived fibrin releasates: composition and use for the culture of cell lines and human primary cells.

We have evaluated the capacity of two human blood fractions to substitute for FBS as growth medium supplement for human and animal cell cultures. Non-anticoagulated blood from volunteer donors (N = 13) was centrifuged to isolate a supernatant serum (SS) and a platelet-rich fibrin (PRF) clot which was squeezed to extract the releasate (PRFR). Both materials were characterized for the content in PDGF-AB, TGF-ß1, VEGF, bFGF, EGF, IGF, total protein, albumin, IgG, IgM IgA, fibrinogen, cholesterol, triglycerides, various chemistry analytes and hemoglobin. Cell growth promoting activity of pooled SS and PRFR at 1, 5, and 10% in growth medium was evaluated over 7 days using human (HEK293, MG-63) and animal (SIRC, 3T3) cell lines and two human primary cultures (gingival fibroblasts and periodontal ligaments). Viable cell count was compared to that in cultures in FBS free-medium and 10% FBS supplement. SS and PRFR at 1-10% stimulated cell growth significantly more than FBS-free medium and in a way similar to 10% FBS in all cultures apart from 3T3. These two human blood-derived fibrin releasates are equally efficient to substitute for FBS as supplement for cell cultures and could be useful for specialized applications in regenerative medicine, dentistry and oral implantology, or cell therapy.

Expansion of adipose tissue mesenchymal stromal progenitors in serum-free medium supplemented with virally inactivated allogeneic human platelet lysate.

BACKGROUND: Single-donor or pooled platelet lysates (PL) can substitute for fetal bovine serum (FBS) for mesenchymal stromal cell (MSC) expansion. However, for clinical applications of MSCs, the use of virally inactivated PL would be desirable. Recently, we have developed a solvent/detergent (S/D)-treated human PL preparation (S/D-PL) rich in growth factors. The capacity to use this virally inactivated preparation for MSC expansion needs to be evaluated. STUDY DESIGN AND METHODS: Platelet concentrates were treated by S/D (1% tri-n-butyl phosphate and 1% Triton X-45), extracted by oil, purified by C18 hydrophobic interaction chromatography, and sterile filtered. S/D-PL was compared to FBS as a medium supplement (10% vol/vol) for isolating, maintaining, and expanding adipose tissue-derived MSCs (AT-MSCs). Cell morphology; proliferation kinetics; immunophenotype; differentiation capacity toward the chondrogenic, osteogenic, and osteogenic lineages; and cytokine antibody array were assessed. RESULTS: AT-MSCs had a typical spindle morphology and proliferated in S/D-PL at least as well as in FBS. Immunophenotype at Passage 7 was characteristic of MSCs and similar for both culture conditions. Differentiation capacity into the three lineages was maintained and chondrogenesis was enhanced by S/D-PL. In a 120 human cytokine antibody array analysis, 73 cytokines were detected in S/D-PL, including 22 with a concentration higher than in FBS. CONCLUSION: S/D-PL is an alternative to FBS for AT-MSC maintenance and expansion, does not compromise the differentiation capacity nor the immunophenotype, and may accelerate chondrogenesis. S/D-PL protocols for MSC clinical scale-up may represent a major step toward challenging new use in stem cell therapies.

A virally inactivated platelet-derived growth factor/vascular endothelial growth factor concentrate fractionated from human platelets.

BACKGROUND: Human platelet concentrates (PCs) may be a source material to produce purified growth factors (GFs) for clinical use or cell therapy. However, no fractionation process of therapeutic-grade GF from PCs has ever been developed. STUDY DESIGN AND METHODS: PCs were virally inactivated by solvent/detergent (S/D) treatment, subjected to oil extraction to remove part of the S/D agents, and fractionated on a SP-Sepharose (SP) chromatographic column equilibrated in a phosphate-buffered saline (PBS) buffer, pH 7.5. The breakthrough was recovered, and the column was washed with the PBS buffer and then eluted by a 0.7 mol/L NaCl-PBS buffer pH 7.5 (SP-eluate). The SP-breakthrough and SP-eluate were characterized for their content in GF, proteins, lipids, and S/D agents. The MTS value of three cell lines cultivated in a medium containing 10% fetal bovine serum supplemented with 1% to 3% of SP-eluate or recombinant human (rHu) platelet-derived growth factor (PDGF)-BB was compared. RESULTS: The SP-eluate contained a mean of 47, 17, and 6 ng/mL PDGF-AB, -BB, and -AA, respectively, and 0.26 ng/mL vascular endothelial growth factor (VEGF). It was largely depleted of transforming growth factor-ß1 (2.33 ng/mL), epidermal growth factor (0.09 ng/mL), insulin-like growth factor (3.40 ng/mL), albumin, immunoglobulin (Ig)G, IgM, IgA, and fibrinogen, which were mostly in the breakthrough. tri-n-butyl phosphate and Triton X-45 were less than 2 ppm. Cell growth-promoting activity of the SP-eluate was at least as good as that of rHu-PDGF-BB. CONCLUSION: Human PC can be fractionated into a purified, virally inactivated PDGF and VEGF concentrate, opening perspectives for the development of a new range of blood products for clinical use and cell therapy procedures.

A novel virally inactivated human platelet lysate preparation rich in TGF-beta, EGF and IGF, and depleted of PDGF and VEGF.

There is emerging interest in the use of standardized virally inactivated human platelet lysate preparations rich in GFs (growth factors) for cell cultures, cell therapy and clinical applications. In the present paper, we report a simple process to prepare a virally inactivated platelet lysate preparation rich in TGF-beta1 (transforming growth factor-beta1), EGF (epidermal growth factor) and IGF (insulin-like growth factor) and depleted of PDGF (platelet-derived growth factor) and VEGF (vascular endothelial growth factor). Apheresis platelet concentrates were treated by the S/D (solvent/detergent) viral inactivation procedure, then subjected to an oil extraction followed by adsorption with activated charcoal and finally sterile-filtered. The resulting preparation contained a mean of 368.4, 2.4 and 54.7 ng/ml of TGF-beta1, EGF and IGF respectively. PDGF-AB and VEGF were essentially completely removed by the charcoal treatment. The mean albumin, IgG, IgM and IgA and fibrinogen contents were approx. 40.0, 8.5, 0.87, 1.66 and 2.65 mg/ml respectively, cholesterol and triglycerides were at 15 and 20.7 mg/ml respectively and TnBP (tri-n-butyl phosphate) and Triton X-45 were at 8.7 and 8.8 p.p.m. respectively. Supplementing MEM (minimum essential medium) with 1-10% of this S/D-treated platelet lysate promoted the proliferation of MG63 and SIRC cell lines as well as, or better than, 10% (v/v) FBS (fetal bovine serum), as based on the MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay. The process used to prepare such S/D-treated platelet lysates is easily scalable for industrial production. Our results open up the possibility to evaluate the potential of this new preparation for stem cell expansion and/or bone tissue engineering and regeneration.

Influence of ethanol on the release of growth factors in human blood-derived platelet gels.

Platelet gels (PG) are new topical single-donor blood products which are attracting great interest in regenerative medicine. They are obtained by mixing a platelet-rich plasma fraction with thrombin to generate a fibrin gel enriched in platelet growth factors (GF). The type of thrombin preparation may affect PG reproducibility. We have determined the impact of 14.6% (v/v) ethanol-stabilized thrombin (EHT) on the release of GF by platelets. Various ratios of EHT and platelet concentrates were mixed to obtain from 2.43 to 7.96% ethanol concentration. Platelet-derived growth factor-AB (PDGF-AB), transforming growth factor-beta1 (TGF-beta1), vascular endothelium growth factor (VEGF), epidermal growth factor (EGF), and insulin-like growth factor-1 (IGF-1) were assessed at 5, 120, and 300 min after PG formation. Protein profiles of thrombin and PG releasates were analyzed by SDS-PAGE. The amount of PDGF-AB, TGF-beta1, and VEGF released per platelet decreased significantly (p<0.05) with increasing ethanol concentrations but, however, not that of EGF. IGF-1 content was stable, consistent with its presence mostly in plasma. SDS-PAGE indicated that ethanol did not affect fibrin formation. In conclusion, ethanol has a significant impact on the amount of GF released by platelets and should be strictly controlled to standardize PG and optimize clinical benefits.

Method development of immunoglobulin G purification from micro-volumes of human serum for untargeted and targeted proteomics-based antibody repertoire studies.

Immunoglobulins (Igs) are major serum proteins which play important roles in immunity. Both untargeted and targeted proteomic workflows can be applied to investigate antigen-binding sites and the glycosylation profiles of Igs. For a more-comprehensive picture of IgG from human serum, we developed an IgG purification process and coupled the standardized method to untargeted and targeted proteomic workflows for IgG investigations. Parameters such as the type of purification beads, volume of the bead slurry, incubation conditions, and binding capacities were evaluated in this study. Only 2 µL of human serum was required for each sample. The performance of coupling the purification process to untargeted proteomics in the IgG analysis was evaluated by comparing normalized abundances of IgG subclass-specific peptides with quantification results from an ELISA. Pearson's correlation values were all >0.82. Targeted proteomic workflow was applied to serum samples from patients with autoimmune pancreatitis and from healthy controls, and the results corresponded to clinical findings that IgG4-related peptides/glycopeptides showed higher abundances in the diseased group. The developed IgG purification process is simple and requires small sample volume, and it can be coupled to targeted and untargeted proteomic workflows for clinical investigations in the future.

In vitro release of growth factors from platelet-rich fibrin (PRF): a proposal to optimize the clinical applications of PRF.

OBJECTIVE: Determine the release of growth factors (GF) from platelet-rich fibrin (PRF) and supernatant serum to optimize clinical use. STUDY DESIGN: Platelet-derived growth factors-AB (PDGF-AB), transforming growth factor-beta1 (TGF-beta1), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), and insulin-like growth factor-1 (IGF-1) were quantified in PRF releasate and in the supernatant serum (N = 8) over 300 minutes after clot formation. Protein profiles were determined by SDS-PAGE. RESULTS: Mean quantity of PDGF-AB, TGF-ss1, VEGF, and EGF in PRF releasate increased significantly to about 52, 72, 1, and 3 ng, respectively, whereas mean IGF-1 content remained at 250 ng. GF was also found in serum supernatant. Protein profiles of the releasates and the supernatant serum were similar. CONCLUSION: The PRF membrane should be used immediately after formation to maximize release of GF to the surgical site. The remaining fluid can be recovered as an additional source of GF for grafting.