El negocio de la medicina regenerativa y las células madre: confusión con implicaciones legales / The regenerative medicine and stem cell business: confusion with legal implications

El auge de la medicina regenerativa y el crecimiento de la oferta de terapias autólogas obtenidas a partir de sangre, células o tejidos de los propios pacientes se ha visto favorecido por la actual disponibilidad de diversos dispositivos comerciales de fácil manejo que permiten la elaboración de los productos y su aplicación dentro de un mismo procedimiento. Independientemente de las dudosas eficacia y seguridad de muchos de los tratamientos que se ofrecen bajo el reclamo de las células madre o la medicina regenerativa, la mayor parte de los centros y de los profesionales que ofrecen estos tratamientos desconocen los requisitos y las implicaciones legales de su uso. Una confusión frecuente consiste en no distinguir entre la autorización que requiere el propio dispositivo, considerado producto sanitario, y la autorización para el uso del producto obtenido, que en general se trata de un medicamento, ya sea de terapia avanzada o no, o de un trasplante. Por otra parte, es frecuente que estos tratamientos tengan un carácter experimental, por lo que su administración en ese caso, además de requerir la evaluación ética correspondiente y la autorización de diversos organismos reguladores, debe ofrecerse de forma gratuita y tras recabar el consentimiento informado del paciente y contratar una póliza de seguros específica. En este artículo se presentan, de forma resumida, los principales requisitos para la aplicación de estos productos biológicos autólogos, con el objetivo de que puedan servir de guía tanto para los profesionales que los prescriben como para aquellos que inspeccionan los centros donde se administran. Por último, se ofrecen algunas recomendaciones para los pacientes. (AU)

The rise of regenerative medicine and the growth of the offer of autologous therapies, obtained from blood, cells or tissues of the patients, have been favoured by the current availability of an increasing number of commercial devices. Most of these devices are easy to use, allowing the elaboration of products and its application within the same procedure. Regardless of the questionable efficacy and safety of many of the treatments offered under the claim of stem cells or regenerative medicine, most of the centres and professionals offering these treatments are unaware of the legal requirements and implications of their use. A common confusion consists in not distinguishing between the authorization required by the equipment itself, considered a medical device, and the authorization for the use of the product obtained, usually considered a medicinal product (whether advanced therapy or not) or a transplant. Moreover, these treatments frequently have an experimental nature. In that case, in addition to requiring the corresponding ethical evaluation and the authorization of various regulatory bodies, their administration must be offered free of charge, obtaining the patient's informed consent and after contracting a specific insurance policy. In this article we present a brief summary of the main requirements for the application of these autologous biological products with the aim of serving as a guide both for the professionals who prescribe them and for those who inspect the centres where the products are administered. Finally, we include some recommendations for patients. (AU)

[The regenerative medicine and stem cell business: confusion with legal implications]. / El negocio de la medicina regenerativa y las células madre: confusión con implicaciones legales.

The rise of regenerative medicine and the growth of the offer of autologous therapies, obtained from blood, cells or tissues of the patients, have been favoured by the current availability of an increasing number of commercial devices. Most of these devices are easy to use, allowing the elaboration of products and its application within the same procedure. Regardless of the questionable efficacy and safety of many of the treatments offered under the claim of stem cells or regenerative medicine, most of the centres and professionals offering these treatments are unaware of the legal requirements and implications of their use. A common confusion consists in not distinguishing between the authorization required by the equipment itself, considered a medical device, and the authorization for the use of the product obtained, usually considered a medicinal product (whether advanced therapy or not) or a transplant. Moreover, these treatments frequently have an experimental nature. In that case, in addition to requiring the corresponding ethical evaluation and the authorization of various regulatory bodies, their administration must be offered free of charge, obtaining the patient's informed consent and after contracting a specific insurance policy. In this article we present a brief summary of the main requirements for the application of these autologous biological products with the aim of serving as a guide both for the professionals who prescribe them and for those who inspect the centres where the products are administered. Finally, we include some recommendations for patients.

Promoting the ethical use of safe and effective cell-based products: the Andalusian plan on regenerative medicine.

With regard to regenerative medicine, the expectations generated over the last two decades and the time involved in developing this type of therapies, together with the availability of devices that allow point-of-care treatments through the rapid isolation of cellular or plasma products from patients in the operating theater, represent the perfect breeding ground for the offering of unproven or unregulated therapies on a global scale. A multidisciplinary approach-one based on the collaboration of institutions that, from the perspective of their area of competence, can contribute to reversing this worrying situation-to this problem is essential. It is a priority for local health authorities to take measures that are adapted to the particular situation and regulatory framework of their respective territory. In this article, the authors present the regenerative medicine action plan promoted by the Andalusian Transplant Coordination (i.e., the action plan for the largest region in Spain), highlighting the aspects the authors believe are fundamental to its success. The authors describe, in summary form, the methodology, phases of the plan, actions designed, key collaborators, important milestones achieved and main lessons they have drawn from their experience so that this can serve as an example for other institutions interested in promoting the ethical use of this type of therapy.

False-Positive Tumor During Organ Retrieval: All Cats Are Gray in the Dark.

OBJECTIVE: Efforts to expand the organ donor pool to meet growing transplant demands remains a top priority, as does maintaining the quality and safety standards of potential recipients. There is a short window of time from organ retrieval to decision making on organ acceptance, based on the available data. Furthermore, the limitations of intraoperative biopsy can often lead to donor or organ refusal due to a suspected tumor, which, if not confirmed in the final biopsy, results in the loss of a transplant opportunity. METHODS: Donor characteristics and organs discarded on suspicion of neoplastic disease at the time of extraction were analyzed in Andalusia between January 2014 and July 2018. The variable analysis included sociodemographic data, type of donor, location of the potential malignancy, histopathologic examination, and discarded organs. RESULTS: A total of 43 cases were identified. The organs of 33 donors (76.7%) were discarded. Kidneys were the most frequent location for a suspected tumor (44%), followed by the liver (21%). In 18 of the 43 cases (42%), the suspected malignancy was not confirmed, and of these, only 3 livers and 1 kidney were implanted. Sixty potentially transplantable organs were discarded, including those that would have been extracted and/or implanted in the absence of a suspected tumor. CONCLUSIONS: These results highlight the need not only to improve the accuracy of intraoperative biopsies but to seek new decision-making strategies for the short interval after organ retrieval. This involves avoiding both extremes of donation contraindications, while maintaining quality and safety standards.

Antibodies against heterogeneous nuclear ribonucleoprotein K in patients with cardiac allograft vasculopathy.

BACKGROUND: Cardiac allograft vasculopathy (CAV) is the most serious long-term complication after cardiac transplantation. T-cell-mediated immune response has been implicated as the central mechanism for this form of graft rejection, but the role of humoral immunity is still controversial. METHODS: This study investigated whether human leukocyte antigen (HLA) and non-HLA antibodies are associated with CAV and if their presence can be used to identify patients at high risk of developing CAV. Diagnosis of CAV was made by angiography and intravascular ultrasound (IVUS) technology. Sera from 48 heart transplant recipients were assessed for the presence of antibodies. RESULTS: Although anti-HLA or anti-major histocompatibility complex class I chain-related gene A (MICA) antibodies in patients with or without CAV were not statistically different, heterogeneous nuclear ribonucleoprotein K (hnRNP-K) was identified as a new antigenic target after the screening of a human coronary artery smooth muscle cells complementary DNA (cDNA) expression library with a serum sample from a CAV patient. Four years after transplantation, presence of anti-hnRNP-K antibodies was significantly higher in the IVUS-defined CAV group (85.3%) and angiography-defined CAV patients (90.5%) compared with the non-CAV group (p < 0.0001 and p = 0.0023 respectively). CONCLUSIONS: The presence of anti-hnRNP-K antibodies 4 years after the transplant is statistically associated with CAV disease, regardless of the diagnostic technique. Therefore, prospective detection of these antibodies could be proposed as a helpful biomarker in CAV diagnosis.

Complement component 4d immunostaining in liver allografts of patients with de novo immune hepatitis.

De novo immune hepatitis (DNIH) is a form of late graft dysfunction after liver transplantation. The fine mechanisms leading to the development of DNIH are not known, and whether this hepatitis is a form of rejection or a result of an auto/alloimmune injury has not been established. In our patients, DNIH was always preceded by the production of donor-specific antibodies against the glutathione S-transferase T1 (GSTT1) enzyme because of a genetic mismatch in which the donors carried the wild-type gene and the recipients displayed the null genotype. Complement component 4d (C4d) immunopositivity in 12 paraffin-embedded liver biopsy samples from 8 patients diagnosed with DNIH associated with anti-GSTT1 antibodies was retrospectively evaluated. Six patients with a diagnosis of chronic rejection (CR) and 7 patients with hepatitis C virus recurrence were included as control groups. Among the patients with DNIH, 7 showed C4d-positive immunostaining localized in the portal tracts, whereas in the tested biopsy samples of the 2 control groups, this staining pattern was absent. Four biopsy samples of the CR group showed C4d-positive sinusoidal staining. This study confirms the activation of the complement pathway in the presence of donor-specific antibodies, which was shown by the deposition of C4d elements in liver biopsy samples of patients with DNIH. The use of C4d as a marker of antibody-mediated rejection in liver allografts in the presence of antidonor antibodies is discussed, and it may contribute to improved differential diagnoses based on biopsy findings.

Donor-specific antibodies against HLA, MICA, and GSTT1 in patients with allograft rejection and C4d deposition in renal biopsies.

BACKGROUND: Production of antibodies against donor-specific antigens is one of the central mechanisms of allograft rejection. This antibody-mediated rejection (AMR) is evidenced by the presence of circulating donor-specific antibodies and deposition of complement component C4d on renal endothelium. Although anti-human leukocyte antigen (HLA) antibodies account for a high proportion of AMR, in many cases anti-HLA antibodies cannot be demonstrated. In liver transplant, antibodies against glutathione-S-transferase T1 (GSTT1) expressed on the graft may induce an antibody response leading to a severe graft dysfunction. In addition, presence of antibodies against major-histocompatibility-complex class I chain-related gene A (MICA) has been associated with a poor graft survival in kidney transplantation. METHODS: Pre- and posttransplantation sera from 19 patients fulfilling the criteria for AMR including C4d deposition in renal biopsies were included. Donor-specific antibodies against HLA-I and -II and MICA were studied using Luminex. Anti-GSTT1 antibodies were analyzed by indirect immunofluorescence and by an ELISA method. A control group of 39 patients with graft dysfunction negative for C4d was also included. RESULTS: At the time of the biopsy, 4 (21%) patients had only anti-HLA class I antibodies; 3 (15.8%) had anti-GSTT1, 2 (10.5%) had anti-HLA-class II, and 2 (10.5%) had anti-MICA; four patients had combination of antibodies: HLA-I + MICA (n=1), HLA-I + GSTT1 (n=2), and GSTT1+MICA (n=1). No antibodies were found in 4 (21%) patients. In total, 6 (31.6%) C4d+ patients had anti-GSTT1 antibodies, whereas, among the 39 C4d-negative patients, only 3 (7.7%) had anti-GSTT1 antibodies (P=0.027). CONCLUSION: Besides anti-HLA antibodies, donor-specific antibodies against MICA and GSTT1 antigens could be responsible for the occurrence of antibody-mediated kidney graft rejection.

Positive association of anticytoskeletal endothelial cell antibodies and cardiac allograft rejection.

Using an indirect immunofluorescence method on human umbilical vein endothelial cells (HUVEC), we investigated the presence of antiendothelial cell antibodies (AECA) in 136 pre- and posttransplant serum samples sequentially collected from 31 patients during the first year after cardiac transplantation. A healthy control group was also included (n = 87). Colocalization studies demonstrated a positive staining pattern of different cytoskeletal components (cytoskeletal-antiendothelial cell antibodies, CSK-AECA) including antivimentin, antiactin, antitubulin, and anticytokeratin among heart transplanted patients. Frequency of CSK-AECA in the control group and at day 0 in the transplant group was 18.3 and 22.5%, respectively (p = NS). A progressive increase in the frequency of CSK-AECA was observed after cardiac transplantation: 13.3% at day 15; 22.2% at day 30; 53.8% at day 90, and 58% at day 360. Interestingly, rejection episodes within the first year after transplantation occurred in 83.3% of CSK-AECA-positive and in 30.7% of CSK-AECA-negative patients (p = 0.0045). The presence of antibodies was detected prior to the rejection event and was associated with a poor clinical outcome: rejection episodes occurred at a mean of 36.14 +/- 17 days after transplantation in patients with preexisting AECA and 174.25 +/- 51.9 days after de novo antibody appearance in patients with no antibodies at day 0 (p = 0.029). In conclusion, a progressive increase in the frequency of CSK-AECA was observed following cardiac transplantation; the presence of these antibodies is strongly associated and precedes the rejection episodes. Thus, CSK-AECA could be a good marker for acute graft rejection.

Anti-glutathione S-transferase T1 antibody-mediated rejection in C4d-positive renal allograft recipients.

BACKGROUND: Chronic humoral rejection is a progressive form of graft injury, with defined diagnostic criteria, the crucial one being the evidence of circulating anti-donor antibodies. These antibodies are mainly directed against human leucocyte antigens (HLA), but other targets have also been described. We previously reported that antibodies against the Glutathione S-transferase T1 (GSTT1) enzyme appear in recipients without the GSTT1 gene who receive a graft from a GSTT1-positive donor. The primary aim of this study was to analyse the role of GSTT1 in cases of antibody-mediated rejection (AMR) in the absence of anti-HLA antibodies. A second objective was to describe the distribution of the GSTT1 enzyme in the human kidney. METHODS: Four renal biopsies from four renal transplanted patients with declined renal function and circulating anti-donor GSTT1 antibodies were studied for C4d deposits in sections of paraffin-embedded tissue samples. Anti-donor-specific HLA and MICA antibody detection was done with the Luminex platform and anti-GSTT1 antibodies were tested by indirect immunofluorescence on rat tissues and ELISA assay. DNA of the patients was extracted for GSTT1 genotyping. RESULTS: Four patients with the GSTT1 donor/recipient mismatch developed anti-GSTT1 antibodies 32, 42, 48 and 60 months after the transplant. One patient also had donor-specific anti-HLA antibodies. Their biopsies showed pathologic lesions compatible with chronic antibody-mediated rejection (CAMR), along with positive C4d deposition in peritubular capillaries in three of them, being no valuable in the other case. CONCLUSION: This is the first study reporting an association between the appearance of chronic antibody-mediated renal allograft rejection and the occurrence of de novo production of anti-GSTT1 antibodies, in the absence of anti-HLA donor-specific antibodies. This fact suggests a potential role of the GSTT1 system in anti-graft immune response.