[Recommendations about immunizations in patients with inborn errors of immunity]. / Recomendaciones para la inmunización de pacientes con errores innatos de la inmunidad.

Inborn errors of immunity (IEI) are a heterogeneous group of hereditary disorders that affect in number and/or function different components of the immune system, resulting in an increased risk and severity of infections, autoimmune diseases, allergic manifestations, autoinflammation and malignancy. Inactivated vaccines are generally safe in these patients, but may be ineffective in some cases, due to difference in immunogenicity. However, live viral and bacterial vaccines may lead to disease, with high morbidity and mortality, so it is essential a previous immunological work-out. In this document, the Pediatric Immunology Work Group of the Sociedad Argentina de Pediatría summarizes recommendations about immunizations in patients with IEI, their household contacts, as well as in patients under immunosuppressive treatment and hematopoietic stem cell transplant recipients.

Los errores innatos de la inmunidad (EII) constituyen un grupo heterogéneo de enfermedades hereditarias que afectan el número y/o la función de los distintos componentes del sistema inmune, lo que predispone a un incremento de la tasa y gravedad de infecciones, enfermedades autoinmunes, manifestaciones alérgicas, autoinflamación y malignidad. En estos pacientes, la inmunización con vacunas inactivadas es generalmente segura, pero puede no ser efectiva en determinados grupos de EII, sin generar el efecto protector deseado. La aplicación de vacunas vivas atenuadas (virales y bacterianas) puede llevar al desarrollo de enfermedad asociada a la inmunización, con elevada morbimortalidad, por lo que amerita previamente consultar al especialista. El presente informe resume las conclusiones del Grupo de Trabajo de Inmunología de la Sociedad Argentina de Pediatría respecto a la vacunación en pacientes con EII y sus convivientes, en pacientes bajo inmunosupresión farmacológica y en receptores de trasplante de células precursoras hematopoyéticas.

Pan-lysyl oxidase inhibition disrupts fibroinflammatory tumor stroma, rendering cholangiocarcinoma susceptible to chemotherapy.

BACKGROUND: Cholangiocarcinoma (CCA) features highly desmoplastic stroma that promotes structural and functional resistance to therapy. Lysyl oxidases (LOX, LOXL1-4) catalyze collagen cross-linking, thereby increasing stromal rigidity and facilitating therapeutic resistance. Here, we evaluate the role of lysyl oxidases in stromal desmoplasia and the effects of pan-lysyl oxidase (pan-LOX) inhibition in CCA. METHODS: Resected CCA and normal liver specimens were analyzed from archival tissues. Spontaneous and orthotopic murine models of intrahepatic CCA (iCCA) were used to assess the impact of the pan-LOX inhibitor PXS-5505 in treatment and correlative studies. The functional role of pan-LOX inhibition was interrogated through in vivo and ex vivo assays. RESULTS: All 5 lysyl oxidases are upregulated in CCA and reduced lysyl oxidase expression is correlated with an improved prognosis in resected patients with CCA. Spontaneous and orthotopic murine models of intrahepatic cholangiocarcinoma upregulate all 5 lysyl oxidase isoforms. Pan-LOX inhibition reversed mechanical compression of tumor vasculature, resulting in improved chemotherapeutic penetrance and cytotoxic efficacy. The combination of chemotherapy with pan-LOX inhibition increased damage-associated molecular pattern release, which was associated with improved antitumor T-cell responses. Pan-LOX inhibition downregulated macrophage invasive signatures in vitro, rendering tumor-associated macrophages more susceptible to chemotherapy. Mice bearing orthotopic and spontaneously occurring intrahepatic cholangiocarcinoma tumors exhibited delayed tumor growth and improved survival following a combination of pan-LOX inhibition with chemotherapy. CONCLUSIONS: CCA upregulates all 5 lysyl oxidase isoforms, and pan-LOX inhibition reverses tumor-induced mechanical forces associated with chemotherapy resistance to improve chemotherapeutic efficacy and reprogram antitumor immune responses. Thus, combination therapy with pan-LOX inhibition represents an innovative therapeutic strategy in CCA.

Transplantation in the Pandemic Era: Perspectives on the Utilization of COVID-19 Positive Organs.

BACKGROUND: At early stages of the pandemic, most organ procurements organizations considered COVID-19 infected donors to be ineligible for organ donation. The aim of this survey is to describe the current practices of the utilization of COVID-19 positive organs donors among American Society of Transplant Surgeons (ASTS) members. METHODS: An anonymous 40-question redcap survey was emailed to ASTS members from June to August 2022. RESULTS: One hundred forty-nine surveys from 10 countries were included for analysis. The majority of the responders were men (66.7%) from North America (95%) and identified as transplant surgeons (68.5%). Most work at academic institutions (76.5%). Almost all responders (94%) were willing to accept an organ from a donor with a history of COVID-19 who tested negative at the time of donation, however, there was no consensus on the length of time after the disease was resolved. Approximately 70% indicated they accept organs from asymptomatic donors with active disease. Only 32 responders indicated they would accept an organ from an individual with a history of "severe" COVID-19 infection and less than one third of the responders would accept an organ from a donor who died from COVID-19 infection. Interestingly, 80% indicated they have protocols at their institution to guide the acceptance of such organs. DISCUSSION: Despite new evidence that the transmission of COVID-19 in non-lung organs is extremely rare, the results of this survey suggest significant heterogeneity in practice and perceptions of the use of COVID-19 positive organs across international centers. We suggest that the implementation of a standardized protocol is of paramount importance to continue safe transplant activity.

Progression-Free Survival for Liver Transplant vs Alternative Therapy in Unresectable Colorectal Liver Metastasis.

This cohort study compares survival outcomes between patients with unresectable colorectal liver metastasis who received chemotherapy-based multimodal therapy and patients who underwent liver transplant.

Harmonizing Definitions and Perspectives in Extreme Liver Surgery: A Delphi Experts Consensus.

OBJECTIVE: To propose to our community a common language about extreme liver surgery. BACKGROUND: The lack of a clear definition of extreme liver surgery prevents convincing comparisons of results among centers. METHODS: We used a two-round Delphi methodology to quantify consensus among liver surgery experts. For inclusion in the final recommendations, we established a consensus when the positive responses (agree and totally agree) exceeded 70%. The study steering group summarized and reported the recommendations. In general, a five-point Likert scale with a neutral central value was used, and in a few cases multiple choices. Results are displayed as numbers and percentages. RESULTS: A two-round Delphi study was completed by 38 expert surgeons in complex hepatobiliary surgery. The surgeon´s median age was 58 years old (52-63) and the median years of experience was 25 years (20-31). For the proposed definitions of total vascular occlusion, hepatic flow occlusion and inferior vein occlusion, the degree of agreement was 97%, 81% and 84%, respectively. In situ approach (64%) was the preferred, followed by ante situ (22%) and ex situ (14%). Autologous or cadaveric graft for hepatic artery or hepatic vein repair were the most recommended (89%). The use of veno-venous bypass or portocaval shunt revealed the divergence depending on the case. Overall, 75% of the experts agreed with the proposed definition for extreme liver surgery. CONCLUSION: Obtaining a consensus on the definition of extreme liver surgery is essential to guarantee the correct management of patients with highly complex hepatobiliary oncological disease. The management of candidates for extreme liver surgery involves comprehensive care ranging from adequate patient selection to the appropriate surgical strategy.

Overview of Current Hepatocellular Carcinoma Staging Systems: Is There an Optimal System?

Multiple hepatocellular carcinoma (HCC) staging systems have been proposed and used clinically over time. These may consider clinical, pathological, radiological, or treatment response factors, depending on the model. Given the heterogeneity of HCC treatment in its different stages and the validation of the systems in different populations, they are not universal. Likewise, the improvement in diagnostic tools, as well as novel therapeutic alternatives, have made these models more complex. Despite this, some have been modified over time in line with advances in the field, and although there is no universally accepted one, each has its usefulness, strengths, and weaknesses.

Liver transplantation in Latin America: reality and challenges.

Healthcare systems in Latin America are broadly heterogeneous, but all of them are burdened by a dramatic rise in liver disease. Some challenges that these countries face include an increase in patients requiring a transplant, insufficient rates of organ donation, delayed referral, and inequitable or suboptimal access to liver transplant programs and post-transplant care. This could be improved by expanding the donor pool through the implementation of education programs for citizens and referring physicians, as well as the inclusion of extended criteria donors, living donors and split liver transplantation. Addressing these shortcomings will require national shifts aimed at improving infrastructure, increasing awareness of organ donation, training medical personnel, and providing equitable access to care for all patients.

Liver transplantation for unresectable colorectal liver metastasis.

PURPOSE OF REVIEW: To summarize the current state of liver transplantation (LT) for unresectable colorectal liver metastases (uCRLM), and to address future directions. RECENT FINDINGS: The Norwegian secondary cancer (SECA) I and SECA II studies demonstrated that after LT the 5-year survival of a highly selected group of patients with uCRLM could be as high as 60% and 83%, respectively. After long-term follow-up, the 5- and 10-year survival was shown to be 43% and 26%, respectively. Furthermore, data has accumulated in other countries and a North American study reported a 1.5-year survival of 100%. In addition, steady growth has been demonstrated in the US, with 46 patients transplanted to date and 19 centers enrolling patients for this indication. Lastly, although recurrence is almost universal in patients with a high tumor burden, it has not been an accurate surrogate for survival, reflecting the relatively indolent nature of recurrence after LT. SUMMARY: Growing evidence has shown that excellent survival and even cure can be achieved in highly selected patients with uCRLM, with survival rates far superior than in patients treated with chemotherapy. The next step is to create national registries to standardize selection criteria and establish the optimal approach and best practices for incorporating LT for uCRLM into the treatment armamentarium.

Recomendaciones para el cuidado, prevención de infecciones y quimioprofilaxis en los errores innatos de la inmunidad / Recommendations for care, prevention of infections and chemoprophylaxis in inborn errors of immunity

Los errores innatos de la inmunidad (EII), antes llamados inmunodeficiencias primarias (IDP), son un grupo heterogéneo de trastornos genéticos con defectos en uno o más componentes del sistema inmune. Los pacientes afectados por EII presentan aumentada susceptibilidad a microorganismos únicos o múltiples que se manifestará con infecciones recurrentes de diferente tipo y gravedad dependiendo del tipo de la localización del defecto. La prevención de infecciones es uno de los pilares fundamentales en el abordaje integral de los pacientes con EII. En este trabajo se resumen las conclusiones consensuadas en el Grupo de Trabajo de Inmunología Pediátrica de la Sociedad Argentina de Pediatría, sobre la base de la revisión de la evidencia disponible, respecto a los principios esenciales para el cuidado, la prevención de infecciones y la quimioprofilaxis en los errores innatos de la inmunidad para la orientación del pediatra y especialista dedicados al seguimiento de estas enfermedades.

Inborn errors of immunity, previously named primary immunodeficiency are a heterogeneous group of genetic defects of different components of the immune system. Patients present high susceptibility to an only or several microorganisms, developing recurrent infections; the severity is related to the specific genetic type of immunity defect. The main strategy on the management of these illness is the prevention of infections. These consensus guidelines made by the Pediatric Immunology Work Group of Sociedad Argentina de Pediatría, givese main approaches of infection prevention in order to provide a useful tool for all practitioners who are involved in the management of these patients, based on scientific evidence and broad consensus of a specialized panel expert.

The High Incidence of Occult Carcinoma in Total Hepatectomy Specimens of Patients Treated for Unresectable Colorectal Liver Metastases With Liver Transplant.

OBJECTIVE: To describe the rate of occult carcinoma deposits in total hepatectomy specimens from patients treated with liver transplant (LT) for colorectal liver metastases (CRLM). BACKGROUND: Previous studies have shown that patients with CRLM treated with systemic therapy demonstrate a high rate of complete radiographic response or may have disappearing liver metastases. However, this does not necessarily translate into a complete pathologic response, and residual invasive cancer may be found in up to 80% of the disappearing tumors after resection. METHODS: Retrospective review of 14 patients who underwent LT for CRLM, at 2 centers. Radiographic and pathologic correlation of the number of tumors and their viability before and after LT was performed. RESULTS: The median (interquartile range) number of tumors at diagnosis was 11 (4-23). The median number of chemotherapy cycles was 24 (16-37). Hepatic artery infusion was used in 5 patients (35.7%); 6 (42.9%) underwent surgical resection, and 5 (35.7%) received locoregional therapy. The indication for LT was unresectability in 8 patients (57.1%) and liver failure secondary to oncologic treatment in the remaining 6 (42.9%). Before LT, 7 patients (50%) demonstrated fluorodeoxyglucose-avid tumors and 7 (50%) had a complete radiographic response. Histopathologically, 11 patients (78.6%) had a viable tumor. Nine (64.2%) of the 14 patients were found to have undiagnosed metastases on explant pathology, with at least 22 unaccounted viable tumors before LT. Furthermore, 4 (57.1%) of the 7 patients who demonstrated complete radiographic response harbored viable carcinoma on explant pathology. CONCLUSIONS: A complete radiographic response does not reliably predict a complete pathologic response. In patients with unresectable CRLM, total hepatectomy and LT represent a promising treatment options to prevent indolent disease progression from disappearing CRLM.

[Recommendations for care, prevention of infections and chemoprophylaxis in inborn errors of immunity]. / Recomendaciones para el cuidado, prevención de infecciones y quimioprofilaxis en los errores innatos de la inmunidad.

Inborn errors of immunity, previously named primary immunodeficiency are a heterogeneous group of genetic defects of different components of the immune system. Patients present high susceptibility to an only or several microorganisms, developing recurrent infections; the severity is related to the specific genetic type of immunity defect. The main strategy on the management of these illness is the prevention of infections. These consensus guidelines made by the Pediatric Immunology Work Group of Sociedad Argentina de Pediatría, givese main approaches of infection prevention in order to provide a useful tool for all practitioners who are involved in the management of these patients, based on scientific evidence and broad consensus of a specialized panel expert..

Los errores innatos de la inmunidad (EII), antes llamados inmunodeficiencias primarias (IDP), son un grupo heterogéneo de trastornos genéticos con defectos en uno o más componentes del sistema inmune. Los pacientes afectados por EII presentan aumentada susceptibilidad a microorganismos únicos o múltiples que se manifestará con infecciones recurrentes de diferente tipo y gravedad dependiendo del tipo de la localización del defecto. La prevención de infecciones es uno de los pilares fundamentales en el abordaje integral de los pacientes con EII. En este trabajo se resumen las conclusiones consensuadas en el Grupo de Trabajo de Inmunología Pediátrica de la Sociedad Argentina de Pediatría, sobre la base de la revisión de la evidencia disponible, respecto a los principios esenciales para el cuidado, la prevención de infecciones y la quimioprofilaxis en los errores innatos de la inmunidad para la orientación del pediatra y especialista dedicados al seguimiento de estas enfermedades.

Expanding spectrum, intrafamilial diversity, and therapeutic challenges from 15 patients with heterozygous CARD11-associated diseases: A single center experience.

CARD11-associated diseases are monogenic inborn errors of immunity involving immunodeficiency, predisposition to malignancy and immune dysregulation such as lymphoproliferation, inflammation, atopic and autoimmune manifestations. Defects in CARD11 can present as mutations that confer a complete or a partial loss of function (LOF) or contrarily, a gain of function (GOF) of the affected gene product. We report clinical characteristics, immunophenotypes and genotypes of 15 patients from our center presenting with CARD11-associated diseases. Index cases are pediatric patients followed in our immunology division who had access to next generation sequencing studies. Variant significance was defined by functional analysis in cultured cells transfected with a wild type and/or with mutated hCARD11 constructs. Cytoplasmic aggregation of CARD11 products was evaluated by immunofluorescence. Nine index patients with 9 unique heterozygous CARD11 variants were identified. At the time of the identification, 7 variants previously unreported required functional validation. Altogether, four variants showed a GOF effect as well a spontaneous aggregation in the cytoplasm, leading to B cell expansion with NF-κB and T cell anergy (BENTA) diagnosis. Additional four variants showing a LOF activity were considered as causative of CARD11-associated atopy with dominant interference of NF-kB signaling (CADINS). The remaining variant exhibited a neutral functional assay excluding its carrier from further analysis. Family segregation studies expanded to 15 individuals the number of patients presenting CARD11-associated disease. A thorough clinical, immunophenotypical, and therapeutic management evaluation was performed on these patients (5 BENTA and 10 CADINS). A remarkable variability of disease expression was clearly noted among BENTA as well as in CADINS patients, even within multiplex families. Identification of novel CARD11 variants required functional studies to validate their pathogenic activity. In our cohort BENTA phenotype exhibited a more severe and expanded clinical spectrum than previously reported, e.g., severe hematological and extra hematological autoimmunity and 3 fatal outcomes. The growing number of patients with dysmorphic facial features strengthen the inclusion of extra-immune characteristics as part of the CADINS spectrum. CARD11-associated diseases represent a challenging group of disorders from the diagnostic and therapeutic standpoint, especially BENTA cases that can undergo a more severe progression than previously described.

Humoral response to different SARS-CoV-2 vaccines in orthotopic liver transplant recipients.

BACKGROUND: The safety and efficacy data of the different types of available vaccines is still needed. The goal of the present analysis was to evaluate the humoral response to the COVID-19 vaccines in orthotopic liver transplant (OLT) recipients. METHODS: Participants were included from February to September 2021. No prioritized vaccination roll call applied for OLT patients. Controls were otherwise healthy people. Blood samples were drawn after 15 days of the complete vaccine doses. The samples were analyzed according to the manufacturer's instructions using the Liaison XL platform from DiaSorin (DiaSorin S.p.A., Italy), and SARS-COV-2 IgG II Quant (Abbott Diagnostics, IL, USA). RESULTS: A total of 187 participants (133 OLT, 54 controls, median age: 60 years, 58.8% women) were included for the analysis; 74.3% had at least one comorbidity. The serologic response in OLT patients was lower than in controls (median 549 AU/mL vs. 3450 AU/mL, respectively; p = 0.001). A positive humoral response was found in 133 OLT individuals: 89.2% with BNT162b2 (Pfizer-BioNTech), 60% ChAdOx1 nCOV-19 (Oxford-AstraZeneca), 76.9% with CoronaVac (Sinovac, Life Sciences, China), 55.6% Ad5-nCov (Cansino, Biologics), 68.2% Gam-COVID-Vac (Sputnik V) and 100% with mRNA-1273. In controls the serological response was 100%, except for Cansino (75%). In a multivariable model, personal history of COVID-19 and BNT162b2 inoculation were associated with the serologic response, while the use of prednisone (vs. other immunosuppressants) reduced this response. CONCLUSION: The serologic response to COVID-19 vaccines in OLT patients is lower than in healthy controls. The BNT162b2 vaccine was associated with a higher serologic response.

Low-dose aspirin confers protection against acute cellular allograft rejection after primary liver transplantation.

This study investigated the effect of low-dose aspirin in primary adult liver transplantation (LT) on acute cellular rejection (ACR) as well as arterial patency rates. The use of low-dose aspirin after LT is practiced by many transplant centers to minimize the risk of hepatic artery thrombosis (HAT), although solid recommendations do not exist. However, aspirin also possesses potent anti-inflammatory properties and might mitigate inflammatory processes after LT, such as rejection. Therefore, we hypothesized that the use of aspirin after LT has a protective effect against ACR. This is an international, multicenter cohort study of primary adult deceased donor LT. The study included 17 high-volume LT centers and covered the 3-year period from 2013 to 2015 to allow a minimum 5-year follow-up. In this cohort of 2365 patients, prophylactic antiplatelet therapy with low-dose aspirin was administered in 1436 recipients (61%). The 1-year rejection-free survival rate was 89% in the aspirin group versus 82% in the no-aspirin group (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.63-0.94; p = 0.01). The 1-year primary arterial patency rates were 99% in the aspirin group and 96% in the no-aspirin group with an HR of 0.23 (95% CI, 0.13-0.40; p < 0.001). Low-dose aspirin was associated with a lower risk of ACR and HAT after LT, especially in the first vulnerable year after transplantation. Therefore, low-dose aspirin use after primary LT should be evaluated to protect the liver graft from ACR and to maintain arterial patency.

Pulmonary Alveolar Proteinosis and Multiple Infectious Diseases in a Child with Autosomal Recessive Complete IRF8 Deficiency.

BACKGROUND: Autosomal recessive (AR) complete IRF8 deficiency is a rare severe inborn error of immunity underlying an absence of blood myeloid mononuclear cells, intracerebral calcifications, and multiple infections. Only three unrelated patients have been reported. MATERIALS AND METHODS: We studied an Argentinian child with multiple infectious diseases and severe pulmonary alveolar proteinosis (PAP). We performed whole-exome sequencing (WES) and characterized his condition by genetic, immunological, and clinical means. RESULTS: The patient was born and lived in Argentina. He had a history of viral pulmonary diseases, disseminated disease due to bacillus Calmette-Guérin (BCG), PAP, and cerebral calcifications. He died at the age of 10 months from refractory PAP. WES identified two compound heterozygous variants in IRF8: c.55del and p.R111*. In an overexpression system, the p.R111* cDNA was loss-of-expression, whereas the c.55del cDNA yielded a protein with a slightly lower molecular weight than the wild-type protein. The mutagenesis of methionine residues downstream from c.55del revealed a re-initiation of translation. However, both variants were loss-of-function in a luciferase assay, suggesting that the patient had AR complete IRF8 deficiency. The patient had no blood monocytes or dendritic cells, associated with neutrophilia, and normal counts of NK and other lymphoid cell subsets. CONCLUSION: We describe the fourth patient with AR complete IRF8 deficiency. This diagnosis should be considered in children with PAP, which is probably due to the defective development or function of alveolar macrophages.

Identification of Germline Non-coding Deletions in XIAP Gene Causing XIAP Deficiency Reveals a Key Promoter Sequence.

PURPOSE: X-linked inhibitor of apoptosis protein (XIAP) deficiency, also known as the X-linked lymphoproliferative syndrome of type 2 (XLP-2), is a rare immunodeficiency characterized by recurrent hemophagocytic lymphohistiocytosis, splenomegaly, and inflammatory bowel disease. Variants in XIAP including missense, non-sense, frameshift, and deletions of coding exons have been reported to cause XIAP deficiency. We studied three young boys with immunodeficiency displaying XLP-2-like clinical features. No genetic variation in the coding exons of XIAP was identified by whole-exome sequencing (WES), although the patients exhibited a complete loss of XIAP expression. METHODS: Targeted next-generation sequencing (NGS) of the entire locus of XIAP was performed on DNA samples from the three patients. Molecular investigations were assessed by gene reporter expression assays in HEK cells and CRISPR-Cas9 genome editing in primary T cells. RESULTS: NGS of XIAP identified three distinct non-coding deletions in the patients that were predicted to be driven by repetitive DNA sequences. These deletions share a common region of 839 bp that encompassed the first non-coding exon of XIAP and contained regulatory elements and marks specific of an active promoter. Moreover, we showed that among the 839 bp, the exon was transcriptionally active. Finally, deletion of the exon by CRISPR-Cas9 in primary cells reduced XIAP protein expression. CONCLUSIONS: These results identify a key promoter sequence contained in the first non-coding exon of XIAP. Importantly, this study highlights that sequencing of the non-coding exons that are not currently captured by WES should be considered in the genetic diagnosis when no variation is found in coding exons.

Liver Transplantation as Definitive Treatment of Post-cholecystectomy Bile Duct Injury: Experience in a High-volume Repair Center.

OBJECTIVE: To analyze the perioperative and long-term outcomes of patients undergoing LT due to BDI in a tertiary care center. BACKGROUND: BDI is associated with significant morbidity and long-term impact on quality of life. LT represents the only possibility of a cure in patients with BDI who develop SBC. METHODS: Retrospective cohort study from a prospective LT database. Between 2008 and 2019, patients with SBC due to BDI after cholecystectomy and requiring LT were identified. Perioperative and long-term outcomes were analyzed. RESULTS: Among 354 LT, 12 patients underwent LT to treat post-cholecystectomy BDI and accounted for 3.4% of all LT. The median time from BDI to SBC diagnosis was 9.3 years (2.4-14). The mean time from SBC to inclusion on the waitlist was 2.4years (± 2.2). Postoperative complications occurred in 11 patients (91.6%); mainly infectious (9/12 patients, 75%), followed by renal complications (4/12 patients, 33.3%). Only 2 patients developed major complications, which were the patients who died, resulting in a 90-day mortality of 16.7%. After a mean follow-up of 40.3 months (± 42.2) survival at 1, 3, and 5 years was 83%. CONCLUSIONS: Although BDI is an unusual indication for LT worldwide, it accounted for 3.4% of all LT in our center. Although postoperative mortality remains high, LT is the only possibility of a cure, with acceptable long-term outcomes. Early referral to a tertiary care center is essential to avoid long-term complications of BDI, such as SBC.