Transitional Care for Patients with Congenital Colorectal Diseases: An EUPSA Network Office, ERNICA, and eUROGEN Joint Venture

BACKGROUND

Transition of care (TOC; from childhood into adulthood) of patients with anorectal malformations (ARM) and Hirschsprung disease (HD) ensures continuation of care for these patients. The aim of this international study was to assess the current status of TOC and adult care (AC) programs for patients with ARM and HD.

METHODS

A survey was developed by members of EUPSA, ERN eUROGEN, and ERNICA, including patient representatives (ePAGs), comprising of four domains: general information, general questions about transition to adulthood, and disease-specific questions regarding TOC and AC programs. Recruitment of centres was done by the ERNs and EUPSA, using mailing lists and social media accounts. Only descriptive statistics were reported.

RESULTS

In total, 82 centres from 21 different countries entered the survey. Approximately half of them were ERN network members. Seventy-two centres (87.8%) had a self-reported area of expertise for both ARM and HD. Specific TOC programs were installed in 44% of the centres and AC programs in 31% of these centres. When comparing centres, wide variation was observed in the content of the programs.

CONCLUSION

Despite the awareness of the importance of TOC and AC programs, these programs were installed in less than 50% of the participating centres. Various transition and AC programs were applied, with considerable heterogeneity in implementation, content and responsible caregivers involved. Sharing best practice examples and taking into account local and National Health Care Programs might lead to a better continuation of care in the future.

LEVEL OF EVIDENCE

III.

Urological Impact of Epididymo-orchitis in Patients with Anorectal Malformation: An ARM-Net Consortium Study

INTRODUCTION

 To investigate the current experience of the ARM-Net Consortium in the management of epididymo-orchitis (EO) in patients with anorectal malformations (ARMs), and to identify specific risk factors and the need for urological care involvement.

MATERIALS AND METHODS

 We retrospectively collected data of EO in patients with ARM between 2015 and 2019. Data on urological aspects, ARM type, surgical approach, associated anomalies, diagnosis, and treatment of EO were collected and analyzed.

RESULTS

 Twenty-nine patients were reported by 12 centers. Twenty-six patients with EO (90%) had ARM with a rectourinary fistula. Median age at first EO was 2 years (range: 15 days-27 years). Twenty patients (69%) experienced multiple EO, and 60% of recurrences were ipsilateral. Associated urological anomalies included vesicoureteral reflux (48%), urethral anomalies (41%), neurogenic bladder (41%), and ectopic vas (10%). A positive urine culture during EO was present in 69%. EO was treated with antibiotics (90%), limiting surgical exploration to 14%. Prevention of recurrences included surgery (bulking agents 15%, vasectomy 15%, and orchiectomy 5%) and antibiotic prophylaxis (20%).

CONCLUSION

 Urologists may encounter patients with EO in ARM patients, frequently with positive urine culture. An appropriate urologic work-up for most ARM patients is necessary to identify and treat underlying risk factors. A practical scheme for the work-up is suggested for a close collaboration between pediatric surgeons and urologists.

Talking about sexuality with your own child. The perspective of the parents of children born with arm

PURPOSE

Evaluate whether parents have ever discussed sexuality with their children with anorectal malformations (ARM), which sexuality issues they think should be addressed and who, in their opinion, should address these issues.

METHODS

Parents from the Italian Parents' and Patients' Association for Anorectal Malformation participated in meetings organized by the Association together with local Pediatric Surgical Units and were asked to fill in a questionnaire.

RESULTS

103 parents participated. Overall, 66% of parents had never talked about sex with their children. Children's age was marginally correlated with occasions to talk about sexuality (r = .202, p = 0.53) indicating that the older were the children, the more the parents talked about sexuality. The majority of parents reported that their children should have the possibility to talk about sex with them (72%), psychologists (57%), gynecologists/andrologists (47%), pediatric surgeons (33.5%), surgeons specialized in ARM (39.8%), friends (28%), nurses (24.7%) and teachers (20.4%), respectively. The most important topic they thought their children should address was handling serene sexuality, although the most common topic effectively discussed with them was the conception.

CONCLUSION

Psychologists, gynecologists/andrologists, and pediatric surgeons are seen as key resources for talking about sexuality. A great number of parents express the wish that their children had more opportunities to discuss sexual topics with pediatric surgeons.

The Transition of Care for Patients with Anorectal Malformations and Hirschsprung Disease: A European Survey

This study aimed at evaluating how transition of care is currently being organized in the European Reference Networks (ERNs) health care providers (HCPs) in pediatric areas and in the Anorectal Malformation Network (ARM-Net) Consortium hospitals. An online questionnaire was sent to a total of 80 surgeons, members of or affiliated members of three networks: ARM-Net Consortium, ERN eUROGEN, and ERN ERNICA. Complete information were obtained for 45 HCPs, most of which deal with transition and still see a few adult patients (ca. 10%). Gynecological, gastroenterological, urological, colorectal, and continence issues were the major problems described by adult patients to their physicians, and in line with these prevalent complaints, they are referred to the appropriate adult specialists. Forty percent of patients complain about sexual and fertility problems, but the percentage of andrologists and sexologists involved in the caring of adult patients with ARM/Hirschsprung's disease is low, just above 10.9%. Most hospitals deal with transition, but three basic criteria (i.e., presence of: [1] an official written transitional program, [2] a transitional coordinator, and [3] written information on transition to be handled to patients) are jointly met only by six HCPs. According to the responders, the most important issue requiring improvement is the lack of interest and of specific preparation by adult specialists. The overall results of this exploratory survey confirm the need for the development of comprehensive programs for transition in these rare and complex diseases, and identify the hospitals that, in collaboration with the networks, could share best practices in organizing structured transitional pathways and well follow-ups.

Importance of education and the role of the patient and family in the care of anorectal malformations

During this early part of the 21st century online technology has prompted many major advances in medical care. In this section we argue that this is particularly evident in the treatment and care of patients born with Anorectal Malformation (ARM) and Hirschsprung's Disease (HD). Our stories show that anyone born with these complex colorectal conditions in the 20th century was destined to a life of isolation and stigma. Here we explore the lack of understanding and recognition of the psychological effects on children and families which has characterised this period. We show that advances in clinical practice has been supported by developing social media platforms. There has been a rapid creation of online support groups for patients and families which has enabled survivors' greater access to patient and parent organizations across the globe and thereby stimulated a sense of belonging and solidarity. Online technology and social media platforms have also opened up the opportunity for pediatric medical professionals to provide a greater level of patient education. There is no doubt families have become much more aware of the complexities of ARM & HD and achieved greater comfort and understanding of their needs. We have generated "lightbulb moments" for pediatric providers with adult ARM & HD patients, enabling them to share their lived experiences in a therapeutic exchange. In the past survivors felt they were abandoned by the adult healthcare system. We are seeing evidence-based research of major psychosocial issues experienced by adult patients and, as a result, improved understanding of how to treat ARM & HD survivors across their whole of life journey. The winds of change continue to direct our cohorts to a mature approach based on improving levels of interactive communication and education. We argue that this maturity has mostly been facilitated by the use of online technology and the ensuing collaboration between providers and patient and parent organizations.

Ongoing care for the patient with an anorectal malfromation; transitioning to adulthood

Planned health care transition can improve the ability of young adults to manage their own health care to effecively use health services and ultimately maximize life-long functioning and well-being. Transitional care is a purposeful, planned process that addresses the medical, psychosocial and educational needs of adolescents and young adults with chronic physical and medical conditions as they move from child-centered to adult-oriented healthcare systems. Unsuccessful surgical transtion may result in physical and mental health implications for young patients, negative long-term outcomes and suboptimal use of health care resources. Anorectal malformation and Hirschsprung patients are an especially vulnerable patient population with ongoing surgical, physiologic and pyschosocial challenges.

Non-financial conflicts of interest: contribution to a surgical dilemma by the European Reference Networks for Rare Diseases

PURPOSE

Conflicts of interest can impede both research and medical treatment. The European Reference Networks require their members to deal with financial and non-financial conflicts according to an explicit protocol. In a literature review, we identified relevant interests in paediatric surgery, and drafted such a policy.

METHODS

We conducted a Pubmed query and identified additional publications based on the content of the papers.

RESULTS

58 titles were identified. According to their abstracts, 10 publications were studied in full text. A scientific taxonomy does not yet exist, but a variety of factors are mentioned. Non-financial conflicts of interest are addressed less accurately and less frequently than financial ones, especially regarding surgical treatment. Since the clinical effect of surgical volume was identified as being relevant, additional 29 respective publications were analysed. This volume-quality relationship causes conflicts of interest for the many surgeons treating a broad spectrum of rare conditions. We present a recommendation that may guide referral of patients requiring complex surgery to centres with a higher volume.

CONCLUSIONS

Non-financial conflicts of interest need to be dealt with more accuracy, especially with regard to surgery in rare, complex congenital conditions. The European Reference Networks offer a framework to mitigate these conflicts.

Sexual well-being in adolescent and young adults born with arm: the perspective of the patients

PURPOSE

Sexual well-being and sexual functioning are understudied in patients born with ARM. The aim of this exploratory study was to investigate sexual history, main fears, and problems encountered during sexual relationships.

METHODS

Before participating in a sexual education intervention, 21 adolescents or young adults (12 males; mean 28.8; SD 10.6) born with ARM, answered a ten-item questionnaire specifically developed to evaluate sexual well-being. Percentages and Chi-square were calculated.

RESULTS

52.4% were married/had a partner. The majority (71%) declared that had sexual relationships. Mean age of the first sexual relationship was 18.8 (2.7) and 22.7 (3.8) for males and females, respectively. Females reported both more fear and experience of pain during sexual intercourse, compared to males. Main experienced problems and fears for male patients were loss of feces and premature ejaculation, followed by the fear of lack of erection and managing contraception. Main experienced problems and fears in females were loss of feces, pain, lack of desire, and lack of lubrication. In only few cases, patients asked for advices to a pediatric surgeon or to an adult surgeon specialized in ARM.

CONCLUSIONS

Adult and adolescent patients may benefit of andrological/gynecological evaluation, psychological support, and sexual counseling to improve their sexual well-being.

Self-efficacy beliefs, faecal incontinence and health-related quality of life in patients born with anorectal malformations

AIM

Anorectal malformations (ARMs) are rare congenital colorectal anomalies with long lasting consequences, among which faecal incontinence is one of the most relevant since it may strongly affect patients' health-related quality of life (HRQoL). Although a growing body of literature supports the importance of self-efficacy in chronic disease health outcomes, only few studies have focused on self-efficacy in ARMs and in faecal incontinence. The purpose of the present study is to examine the mediational role of self-efficacy in the path between faecal incontinence and HRQoL in patients born with ARMs.

METHOD

Ninety-eight adult patients from the Italian Association for Anorectal Malformations (AIMAR) responded to measures of faecal incontinence, self-efficacy for managing ARM consequences, and physical and mental HRQoL (SF-36). Data were analysed by means of structural equation models.

RESULTS

The tested model provides support for the guiding hypothesis. Fit indices indicate that the model fits the data well (χ²  = 33.48, df = 23, P = 0.07; comparative fit index [CFI] = 0.97; root mean square error of approximation [RMSEA] = 0.07; standardized root mean square residual [SRMR] = 0.05). Faecal incontinence has negative effects on both physical and mental HRQoL, as well on self-efficacy. In turn, self-efficacy has a positive and direct effect on mental HRQoL.

CONCLUSION

Faecal incontinence is the most relevant and negative factor influencing HRQoL; in addition, self-efficacy contributes in reducing emotional distress and in improving mental health outcomes. Longitudinal and controlled studies may be helpful to evaluate the effectiveness of self-efficacy interventions in improving mental HRQoL in patients with faecal incontinence.

Transition of care in patients with anorectal malformations: Consensus by the ARM-net consortium

OBJECTIVES

To develop the first consensus to standardize the management of patients with Anorectal Malformations (ARMs) transitioning from childhood to adulthood.

METHODS

A dedicated task force of experts performed an extensive literature review and multiple meetings to define the most important aspects of transition of care. The findings were discussed with all ARM-net consortium members and a set of practical recommendations agreed upon at the annual meeting in 2016.

RESULT

We defined seven domains that are essential to provide an effective and practical transition process. Within each domain we have developed a set of key recommendations that are important to be considered for ARM patients entering the age of transition.

CONCLUSIONS

It is crucial that transition begins at an early age with regular and well-structured follow-up. Cooperation with a selected multidisciplinary team of pediatric and adult practitioners is required to prepare patients and families for effective transition to adult care and to reduce long term morbidity.

TYPE OF STUDY

Review/Consensus paper.

LEVEL OF EVIDENCE

III.

Tethered cord in patients affected by anorectal malformations: a survey from the ARM-Net Consortium

PURPOSE

The goal of this study was to determine the degree of consensus in the management of spinal cord tethering (TC) in patients with anorectal malformation (ARM) in a large cohort of European pediatric centers.

METHODS

A survey was sent to pediatric surgeons (one per center) members of the ARM-Net Consortium.

RESULTS

Twenty-four (86%) from ten different countries completed the survey. Overall prevalence of TC was: 21% unknown, 46% below 15, and 29% between 15 and 30%. Ninety-six agreed on screening all patients for TC regardless the type of ARM and 79% start screening at birth. Responses varied in TC definition and diagnostic tools. Fifty percent of respondents prefer ultrasound (US), 21% indicate either US or magnetic resonance (MRI) based on a pre-defined risk of presenting TC, and 21% perform both. Discrepancy exists in complementary test: 82% carry out urodynamic studies (UDS) and only 37% perform somatosensory-evoked potentials (SSEP). Prophylactic untethering is performed in only two centers (8%).

CONCLUSIONS

Survey results support TC screening in all patients with ARM and conservative management of TC. There is discrepancy in the definition of TC, screening tools, and complementary test. Protocols should be developed to avoid such variability in management.

The Challenges of the European Anorectal Malformations-Net Registry

Anorectal malformations (ARM) have a low prevalence, patients need specialized surgical care, and in many cases, patients born with ARM even need life-long aftercare. Due to its low prevalence most patients are still treated in low-volume pediatric surgical centers without any adequate monitoring of the outcome. Data on prevalence, comparison of different surgical techniques, and prospective outcome measurements are still scarce and difficult to interpret. In 2010, a consortium was founded (ARM-Net consortium) including several European pediatric surgical centers to collaborate more in research and share knowledge on ARM. One of the structures started by the consortium was an ARM-Net registry for the inclusion of all future patients treated in these centers. With this review, we report the structure of the ARM-Net registry, some of the results, and discuss the challenges we faced and still face after its introduction in 2010.

Transition from childhood to adolescence: Quality of life changes 6 years later in patients born with anorectal malformations

BACKGROUND/PURPOSE

Disease-specific quality of life (QoL) may be more or less relevant when children enter preadolescence/adolescence. Few attentions have been given to development and transition periods. Aim of the present longitudinal study is to evaluate ARM specific changes in QoL and the stability of QoL over 6 years.

METHODS

Questionnaires were sent to families of the AIMAR Association (in 2007 and in 2013/2014). They included the Hirschsprung's Disease/ARM QoL Questionnaire (HAQL, [1]). Rank correlations and within group comparisons for the HAQL subscales were conducted analyzing the scores of time 1 vs time 2. Gender effects were tested.

RESULTS

134 parents answered the questionnaires at time 1 and 73 at time 2. Results of the repeated Analyses of Variance indicated improvements in the continence subscales ("Presence of Diarrhea," "Fecal Continence"). QoL significantly worsened in "Social and Emotional Functioning" and in "Body Image" areas. The analysis of stability of change indicates that QoL scores remain stable, with the exception of the Body Image area.

CONCLUSIONS

Despite improvements in the continence areas, parents reported worse levels of QoL in the psychosocial areas, as their child grow. As patients grow, they might have more difficulties in daily and social activities, and feel more frequently ashamed and more dissatisfied with their body.

First results of a European multi-center registry of patients with anorectal malformations

BACKGROUND

The European consortium on anorectal malformations (ARM-NET) was established to improve the health care of patients and to identify genetic and environmental risk factors. The aim of the present study was to present the first results on clinical data of a large European cohort of ARM patients based on our registry.

METHODS

In 2010, the registry was established including patient characteristics and data on diagnosis, surgical therapy, and outcome regarding complications. Patients born between 2007 and 2012 were retrospectively added. A descriptive analysis of this cohort was performed.

RESULTS

Two hundred and three ARM patients were included. Syndromes or chromosomal abnormalities were present in 9%. Perineal fistulas were seen most in boys (42%) and girls (29%). Rare forms of ARM were found in 4% of the male and in 14% of the female patients. Forty-five percent of the patients had additional urogenital abnormalities. However, 32% of the patients were never screened for bladder abnormalities. Eight percent were never screened for renal malformations. In the majority of patients (79%), a PSARP was performed for the definitive reconstruction.

CONCLUSION

This collaborative effort provides a representative basis to estimate incidence of ARM types, to discuss differences and similarities in treatment, and health consequences throughout Europe.

Does mothers' perception of social support mediate the relationship between fecal incontinence and quality of life of the child?

PURPOSE

Fecal incontinence is a common problem in children and adolescents with anorectal malformation (ARM) and may negatively impact psycho-social well-being. Mothers' perception of social support has been proved to contribute to children's quality of life (QOL). Considering ARM studies, the role of family and social resources have received little attention. The aim of the present study was to analyze whether mothers' perception of social support mediates the impact of child fecal incontinence on his/her QOL.

METHODS

One hundred and nine mothers with a child born with ARM (aged 6-15 years old; mean age = 11 years) completed questionnaires including the fecal incontinence subscale of the Hirschsprung's Disease/Anorectal Malformation QOL Questionnaire, the Pediatric QOL Inventory, and a social relationship questionnaire. Structural equation models were used to explore the relations hypothesized.

RESULTS

No differences were found in the QOL scores across gender. The hypothesized model fits the data well; mothers' perception of social support partially mediated the relationship between fecal incontinence and QOL.

CONCLUSIONS

An important direction for pediatric surgeons and their interdisciplinary teams may be to develop strategies to strengthen mothers' social relationships.

Long-term disease-specific quality of life in children and adolescent patients with ARM

BACKGROUND

The main aim of the present study was to investigate how fecal incontinence might influence different aspects of quality of life (QOL) in children and adolescents with anorectal malformations (ARMs). We considered both the influence of fecal incontinence at time 1 of the study and the influence of fecal incontinence at time 2 (4 years later) on QOL measured at time 2.

METHODS

A total of 175 parents from the Italian Parents' and Patients' Association for Anorectal Malformations completed a questionnaire about fecal incontinence in their children at time 1 of the study. Four years later, 97 of these parents completed the Hirschsprung Disease/Anorectal Malformation Quality of Life questionnaire. Patient ages ranged from 4 to 17 years. Quality of life areas from the Hirschsprung Disease/Anorectal Malformation Quality of Life questionnaire were considered as outcome variables in a hierarchical regression analyses where fecal incontinence at time 1 and at time 2 served as predictors.

RESULTS

The principal findings indicated that fecal incontinence at time 2 significantly predicted constipating diet, presence of diarrhea, urinary continence, social functioning, emotional functioning, body image, and physical symptoms, also when severity of the malformation was taken into account.

CONCLUSIONS

It is extremely important that pediatric surgeons continue to promote effective bowel management programs and that they work with other specialists and support associations to offer emotional and psychological support to patients with ARM and their families.

Long-term disease-specific quality of life in adult anorectal malformation patients

BACKGROUND

Fecal and urinary incontinence may differently influence various aspects of quality of life (QOL). The main aim of the present study is to determine whether fecal and urinary incontinence measured at time 1 of the study will predict QOL at time 2 (after 4 years), above and beyond the prediction already explained by fecal and urinary incontinence at time 2.

METHODS

Thirty-six adult patients from the Italian Parents' and Patients' Association for Anorectal Malformations answered items about urinary and fecal incontinence at time 1 of the study and completed the Hirschsprung Disease/Anorectal Malformation Quality of Life questionnaire after 4 years from the first questionnaire. Two sets of hierarchical regression analyses were conducted with fecal and urinary incontinence serving as predictors of QOL and the different areas of QOL from the Hirschsprung Disease/Anorectal Malformation Quality of Life serving as outcome variables.

RESULTS

The principal findings indicated that fecal continence is a strong predictor of QOL in the areas of social functioning, emotional functioning, and body image and that urinary incontinence predicted sexual functioning.

CONCLUSIONS

It seems that one's past experience with fecal incontinence is extremely relevant to current QOL, especially for body image. Urinary incontinence contributed less in explaining QOL in our patients, but because it is very relevant for sexual functioning, it should not be disregarded.

Disease-specific quality of life in children and adults with anorectal malformations

PURPOSE

The aim of the present study was to analyze disease-specific quality of life, as assessed by the Hirsch-sprung Disease/Anorectal Malformation Quality of Life (HAQL) questionnaire, in children and adults with ano-rectal malformations (ARM).

METHODS

As much as 175 children and 62 adults who were members of the Italian Association for Anorectal Malformations were asked to complete the Italian version of the HAQL questionnaire developed for this study. For children under 16 years of age, mothers were asked to fill up the questionnaires. Patients were also asked to identify their type of malformation from a list of eight choices.

RESULTS

Most subscales of the Italian HAQL had acceptable reliability. Compared to children, adults reported significantly lower levels of QL on subscales measuring emotional functioning, body image, and physical symptoms.

CONCLUSIONS

Longitudinal studies are needed to clarify whether these results can be attributed to improvements in surgical techniques that have contributed to improved QL in younger cohorts, or if, instead, quality of life in patients with ARM decreases over time. Intervention efforts should focus on bowel management and psychological treatment for ARM-related emotional and body image distress.

Disease-specific quality of life in children and adults with anorectal malformations

PURPOSE: The aim of the present study was to analyze disease-specific quality of life, as assessed by the Hirschsprung Disease/Anorectal Malformation Quality of Life (HAQL) questionnaire, in children and adults with anorectal malformations (ARM). METHODS: As much as 175 children and 62 adults who were members of the Italian Association for Anorectal Malformations were asked to complete the Italian version of the HAQL questionnaire developed for this study. For children under 16 years of age, mothers were asked to fill up the questionnaires. Patients were also asked to indentify their type of malformation from a list of eight choices. RESULTS: Most subscales of the Italian HAQL had acceptable reliability. Compared to children, adults reported significantly lower levels of QL on subscales measuring emotional functioning, body image, and physical symptoms. CONCLUSIONS: Longitudinal studies are needed to clarify whether these results can be attributed to improvements in surgical techniques that have contributed to improved QL in younger cohorts, or if, instead, quality of life in patients with ARM decreases over time. Intervention efforts should focus on bowel management and psychological treatment for ARM-related emotional and body image distress.

Follow-up of anorectal anomalies: the Italian parents' and patients' perspective

BACKGROUND

Several studies addressed the long-term follow-up of anorectal anomalies (ARM) in relation to clinical issues (eg, continence) and quality of life. However, most of these studies are based upon questionnaires designed by physicians and/or health-care professionals, which may be sources of bias.

METHODS

To investigate whether parents of children (patients themselves or older children or adults) who were born with ARM had the perception that they received appropriate care and follow-up, a survey was carried out in Italy, in 2003, among families with children with ARM. A 20-item questionnaire was mailed to 425 patients and parents listed in the AIMAR (Italian association for anorectal malformation) database and was returned by 209 families. The questionnaire covered different aspects of ARM: type of malformations and surgery, associated anomalies, fecal and urinary continence, as well as aspects about information given to the parents and satisfaction of care and follow-up received.

RESULT

The patients and parents demonstrated a good understanding of distribution of malformations and their anatomical classification; nevertheless, 67% of responders had to travel outside their living area for surgery. Bowel management (BM) was commonly used among subjects; however, a significant percentage of patients using regular enemas were still soiling (58 patients were clean and 116 soiled). Urinary continence problems were mostly found in females with cloaca; nevertheless, 21 male patients reported occasional dribbling of difficult interpretation. Most subjects were provided with a good explanation about their or their child's malformation at time of reconstructive surgery, but the same level of information was missing about functional prognosis later in life when the need of an appropriate psychologic support was also felt.

CONCLUSIONS

Patients and parents born with ARM are generally satisfied with the information received and with the short-term postreconstructive follow-up care. At longer follow-up, although more than a quarter of patients are completely clean, there is a significant percentage of subjects who still soil while following a BM program. This is explained by the small number of nurses and BM specialists who are involved in the rehabilitation process and by the lack of appropriate information about functional prognosis that are conveyed to the parents. In this respect, psychologic support in bridging the gap between cure and care may be critical.

Improved storage of erythrocytes by prior leukodepletion: flow cytometric evaluation of stored erythrocytes

In vivo phagocytosis of senescent red blood cells (RBCs) by macrophages occurs 120 days after their release into the circulation. It depends on two sequential signals that trigger phagocytosis: (1) desialylation of membrane glycoconjugates with the exposure of the penultimate beta-galactosyl residues and (2) exposure of phosphatidylserine in the membrane outer leaflet. Leukodepleted and nonleukodepleted RBCs were compared using flow cytometric procedures to determine whether the in vitro deterioration of RBCs during storage might be attributable to an identical mechanism of desialylation induced by leukocyte neuraminidases, resulting in exposure of beta-galactosyl and subsequently phosphatidylserine residues - signals of senescent RBCs. Without prior leukodepletion, stored RBCs showed an increased population of senescent RBCs (using light scatter measurements), extensive desialylation with the exposure of beta-galactosyl residues (using specific fluorescein isothiocyanate [FITC]-lectins), significant exposure of phosphatidylserine in the outer leaflet of the RBC membrane (using FITC-annexin V), and extensive in vitro phagocytosis (using PKH-26-labeled RBCs). There were minimal changes observed with the leukodepleted RBCs. These results lead to the conclusion that leukocyte enzymes, including neuraminidases, are definitive contributers to the desialylation of RBCs during storage and to the exposure of phosphatidylserine residues. These deleterious effects resulting from highly active leukocyte enzymes are preventable by prior leukodepletion of the stored RBCs. Previously developed flow cytometric procedures to detect in vivo "RBC senescence" have been applied and proved to be reliable criteria to monitor the viability of stored RBCs.

Cellular and molecular mechanisms of senescent erythrocyte phagocytosis by macrophages. A review

Human red blood cells (RBCs) have a life-span of 120 days in circulation, after which they are phagocytized by resident macrophages. Extensive studies have been undertaken by many investigators in order to elucidate the cellular and molecular mechanisms of the erythrophagocytosis. The critical questions addressed by physiologists, clinicians and biochemists are: 'which of the many traumatic blemishes that appear on the erythrocyte surface as it winds its way through the circulation is the primary signal for clearance of the effete RBC from the circulation?', or 'What is the critical signal that it, and it alone, will activate the resident macrophage to adhere to and engulf it?'. Numerous, and often conflicting, hypotheses have been proposed. Each investigator focusing on but one of the many modifications that afflict the cell surface of the ageing erythrocyte, viz changes in either or both the carbohydrate or peptidic moieties of glycoproteins; abolishment of the pre-existing asymmetry in the lipid bilayer with the exposure of phosphatidylserine residues; or alterations in spectrin, to mention but a few. Many of these investigators also have invoked an intermediary role for auto-immune antibodies that recognise the change(s) on the erythrocyte surface and thereby serve as opsonins as a prelude to the erythrophagocytosis. The objective of the present review is to evaluate the data in support of the various hypotheses, and to submit some of our own recent observations involving the use of flow cytometric procedures that: i) provide evidence that the cell surface sialic acid serves as a determinant of the life-span; ii) characterise the senescent erythrocyte population that is specifically captured and phagocytized by macrophages (utilising the rapid and sensitive procedure we developed for quantification of in vitro erythrophagocytosis); and finally iii) provide evidence for the existence of an alternative pathway that is independent of immunoglobulins.

Molecular mechanisms of erythrophagocytosis: flow cytometric quantitation of in vitro erythrocyte phagocytosis by macrophages

A rapid, sensitive, and reproducible flow cytofluorimetric procedure is described for quantitation of erythrophagocytosis based on the use of red blood cells (RBCs) labeled with the fluorescent probe PKH-26. The procedure involves the following steps: i) incubation of PKH-26-labeled erythrocytes with macrophages, ii) removal of un-bound red blood cells, iii) lysis of membrane-bound RBCs, and iv) measurement of extent of phagocytosis by direct flow-cytometric analysis of intact macrophages. Each step was controlled by fluorescence microscopy. Use of fluorescent, instead of radio-labeled RBCs, makes the method more sensitive, rapid, and avoids radioactive hazards. Furthermore, this approach is multi-parametric and can distinguish different populations of macrophages with reference to their erythrophagocytic potential. This technology moreover, has broad applications from the initial step of contact (between effector and target cells to study the specific receptor mediated attachment) to the subsequent cascade of time-dependent changes resulting from that signal transduction.

Molecular mechanisms of erythrophagocytosis. Characterization of the senescent erythrocytes that are phagocytized by macrophages

We have recently developed a flow cytometric assay for the quantitation of erythrophagocytosis, using PKH 26-labeled erythrocytes as the target cells. Using this assay we have shown that there is extensive phagocytosis of desialylated erythrocytes. Furthermore, we have demonstrated that it is the densest population of erythrocytes obtained on a self-forming gradient of Percoll that shows the greatest susceptibility to phagocytosis. We designate this population of erythrocytes as fraction X; it is even denser than the fraction 5 found previously. This population of erythrocytes corresponds to zone X previously seen in the dot-plot of the flow cytometric analyses of human erythrocytes. Further scrutiny of this fraction indicates that a) it shows the greatest reactivity with annexin V, which is specific for the detection of phosphatidylserine (PS) exposed on the outer leaflet of the erythrocyte membrane, b) it is the most susceptible to erythrophagocytosis by resident murine peritoneal macrophages, and c) this erythrophagocytosis of PKH 26-labeled erythrocytes can be inhibited by annexin V and by liposomes containing PS. Scanning electron microscopy of fraction X shows two populations of erythrocytes: (A) spheroechinocytes with filipodes and (B) echinocytes without filipods. After a 2-h period of phagocytosis, the cells remaining in fraction X show a decrease in population A, commensurate with a decrease in reactivity with FITC-labeled annexin V from 65.5 to 24%.

Flow cytometric analysis of human erythrocytes: II. Possible identification of senescent RBC with fluorescently labelled wheat germ agglutinin

In the first paper of a series (Gutowski, et al., 1991) we discussed the use of flow cytometry to follow at the cellular level the aging of red blood cells (RBC) in circulation, using fluorescently labelled lectins and goat anti-human-IgG and -IgM. The Coulter Epics 541 was used for those studies. In this report we describe more extensive experiments using the Becton-Dickinson FACScan flow cytometer, and compare the results with those obtained with the Coulter Epics 541. By changing sample conditions from isotonic to hypotonic, compensation for differences of the two instruments was accomplished. We confirmed our previous observations that RBC react very strongly with fluorescein isothiocyanate labelled wheat germ agglutinin (FITC-WGA) and that there is little change in the intensity of fluorescence given by RBC of all sizes with the exception of the smallest. Reactivity with FITC-WGA is markedly decreased in the presence of competitive inhibitors of sialic acid or upon enzymatic removal of sialic acid from RBC. Removal of sialic acid is accompanied by increased reaction with peanut agglutinin (FITC-PNA). Flow cytometry was also used to monitor the enrichment of a population of smallest RBC (less than 0.05%), isolated from both counterflow centrifugation and the interface obtained from Histopaque separation. These smallest RBC showed low reactivity with FITC-WGA and higher binding of FITC-goat-anti-human-IgG, and -IgM, and therefore represent the most senescent RBC, just prior to their clearance from circulation by the reticuloendothelial system. These observations are in compliance with the hypothesis that physiological desialylation of glycophorin is responsible for clearance of senescent RBC from circulation (Aminoff, 1988).

Flow cytometric analysis of human erythrocytes: I. Probed with lectins and immunoglobulins

A recent review (Aminoff, 1988) summarized the evidence for and against our hypothesis for the role of glycophorin in the senescence and clearance of mammalian red blood cells (RBC) from circulation. This hypothesis postulates the loss of sialic acid from RBC surface in two forms: (a) as vesicles containing the sialoglycoprotein glycophorin, and (b) as free sialic acid residues from glycophorin molecules remaining on cell surface. In this report we demonstrate the applicability of flow cytometric procedures to explore, at the cellular level, time-dependent changes on RBC surface with change in cell size, and with in vivo age. The RBC are probed with fluorescein isothiocyanate (FITC) labelled lectins and goat anti-human-IgG and -IgM. The relative intensity of fluorescence is correlated to the change in RBC size as measured by forward lightscatter. Reactivity of RBC with FITC-labelled wheat germ agglutinin can be inhibited with either 0.2M N-acetylglucosamine or by removal of sialic acid residues with neuraminidase. The properties of the smallest RBC correspond to those of the oldest RBC in their: (a) decreased reactivity with FITC-labelled lectins that recognize sialic acid residues, wheat germ and Limax flavus agglutinins, and (b) increased reactivity with FITC-labelled goat anti-human-IgG and -IgM. These results are compatible with our glycophorin hypothesis. Moreover, they suggest that the initial loss of sialic acid as glycophorin containing vesicles is gradual, while the subsequent step involving the loss of sialic acid residues is rapid and exposes multiple disaccharide galactose beta(1-3)N-acetylgalacosaminyl residues. These unmasked disaccharide sites are recognized by autoimmune IgG, IgM, and lectin-like receptors on macrophages resulting in the clearance of senescent RBC from circulation.

The effect of glycosidases on the survival of rat erythrocytes in circulation

Enzymatic removal of sialyl groups from mammalian erythrocytes resulted in their rapid sequestration from circulation subsequent to autologous transfusion. It has been demonstrated by many investigators that the terminal beta-D-galactosyl group, exposed on red blood cell by in vitro desialosylation, is recognized by an autoimmune anti-galactosyl IgG and/or by a lectin-like receptor on monocytes and macrophages. It is demonstrated herein that the disaccharide structure beta-D-Galp-(1----3)-D-GalpNAc (a) is masked in normal rat RBC, but exposed in asialo-RBC; (b) could be detected with fluorescently-labeled peanut agglutinin; (c) could be released from the asialo-RBC with an endo-N-acetyl-alpha-D-galactosaminidase; and (d) upon its removal by treatment with the endo-N-acetyl-alpha-D-galactosaminidase, enhances the survival of the asialo-RBC in circulation.

Adhesion and erythrophagocytosis of human senescent erythrocytes by autologous monocytes and their inhibition by beta-galactosyl derivatives

Senescent human erythrocytes (RBC) are able to adhere to and be phagocytized by autologous monocytes in vitro to a greater extent than are young RBC. This adhesion and erythrophagocytosis of senescent RBC is inhibited by D-galactose, N-acetyl-D-galactosamine, their corresponding derivatives of bovine serum albumin, and lactose. On the other hand, D-glucose, D-mannose, L-fucose, N-acetyl-D-glucosamine, and their corresponding derivatives of bovine serum albumin are noninhibiting. The glycopeptides released by tryptic digestion of senescent RBC and purified on immobilized peanut agglutinin are the most effective inhibitors of both RBC adhesion and phagocytosis by autologous monocytes obtained from peripheral blood.

Use of 75Se-labeled methionine to study the sequestration of senescent red blood cells

Labeling red blood cells with Na251CrO4 enabled us to study certain aspects of red cell survival and sequestration from the circulation. As a random labeling procedure, however, the 51Cr method has certain limitations. Therefore, we developed a cohort labeling method using 75Se-methionine as a two-rat procedure. This gives us a clear pulse-labeled population of rat red cells to study the dynamics of sequestration. With this labeling procedure, it was possible to demonstrate that 1) there is an increase in the density of red cells with age, 2) a significant sequestration of red cells from the circulation is apparent at the end of 48 days and essentially is complete at the end of 60 days, 3) there is a corresponding uptake of senescent red cells in the spleen, which peaks at 55 days, and 4) the 60-day end point is sharper and is more definitive when the "specific activity" (cpm per red blood cell) of the labeled red cells in the spleen is compared to that of the red cells still in the circulation. Asialo red cells, obtained by removal of sialic acid with sialidase, frequently have been used as a model for the study of sequestration of senescent red cells. With the technique herein described, it was possible to show that while asialo red cells will inhibit the uptake of labeled asialo red cells, they have no effect on the sequestration of senescent red cells. Presumably, different sites and mechanisms of sequestration are involved.

Studies on the sequestration of chemically and enzymatically modified erythrocytes

We have developed an experimental animal model to establish the patterns of sequestration of untreated, as well as chemically and enzymatically modified red blood cells (RBC). The intraperitoneal route of transfusion provides a useful way of transferring large numbers of untreated RBC into small animals and assuring their introduction into the circulation within 24 hr. Moreover, this route "filters" some types of modified erythrocytes, eg, glutaraldehyde treated RBC. From the pattern of sequestration, the RBC in the peritoneal cavity then pass through the liver where other types of modified RBC are sequestered, eg, after trypsin, pronase, protease, or sialidase treatment. Some modified RBC show a preference for the spleen as the site of sequestration, eg, galactose oxidase or N-ethylmaleimide treated RBC. These appear in the spleen despite intraperitoneal transfusion. Relevant to this study is the observation that in the rat old RBC are sequestered both by liver and spleen, while asialoerythrocytes are sequestered by liver only. A possible reason for this difference is discussed in the text.

Isolation and characterization of a glycopeptide from human senescent erythrocytes

A glycopeptide (called "senescence-factor glycopeptide", SF-G) has been isolated from a tryptic digest of human erythrocytes by specific adsorption and elution from immobilized peanut lectin. SF-G was detectable in old but not in young erythrocytes isolated from the same unit of blood. It is present in small quantities, less than 1% of the D-galactose oxidase-borotritide-labeled D-galactosyl residues of erythrocytes. SF-G is free of sialic acid but is quite distinct from a similar glycopeptide isolated from completely desialylated erythrocytes. SF-G binds to spleen monocytes, and this property is abolished upon treatment of SF-G with beta-galactosidase. Some, but not all, of the oligosaccharide chains of the SF-G are of the O-glycosyl type, being released by an endo-N-acetyl-alpha-D-galactosaminidase.

Action of alpha-galactosidase from Clostridium sporogenes and coffee beans on blood group B antigen of erythrocytes. The effect on the viability of erythrocytes in circulation

The effect of alpha-galactosidase, purified from Clostridium sporogenes (Maebashi), was examined on erythrocytes from rats, rabbits and gibbons. The amount of galactose released by alpha-galactosidase from Cl. sporogenes and from coffee beans was compared. The amount of sialic acid released by Vibrio cholera sialidase was also determined. Loss of blood group B specificity following treatment with alpha-galactosidase was demonstrated with anti-B lectin. In animal models, removal of all the alpha-galactosyl residues with the coffee bean or clostridial alpha-galactosidase resulted in no change in the sequestration pattern of the treated erythrocytes over a period of several days. In contrast, erythrocytes treated with sialidase were rapidly sequestered from the circulation.

Structure determination of oligosaccharides isolated from A+, H+ and A-H- hog-submaxillary-gland mucin glycoproteins, by 360-MHz 1H-NMR spectroscopy, permethylation analysis and mass spectrometry

Alkaline borohydride reductive cleavage (beta-elimination) of hog submaxillary glycoproteins from three immunologically determined phenotypes, viz. A+, H+ and A-H-, resulted in the release of a series of neutral and acidic oligosaccharide-alditols. 360-MHz 1H-NMR spectroscopy in combination with methylation analysis and mass spectrometry were used for reinvestigation of the structures of these oligosaccharide-alditols. All are partial structures representing the possible complete and biosynthetically incomplete stages of the chain of a pentasaccharide-N-acetylgalactosaminitol, present in the glycoprotein with blood-group-A activity: (formula: see text) In this way, a prolonged argument about the occurrence of a NeuGc(alpha 2 leads to 6) Gal moiety in these carbohydrate chains, suggested by Aminoff et al. [Aminoff, D., Baig, M. M. and Gathmann, W. D. (1979) J. Biol. Chem. 254, 1788-1793 and 8909-8913] has been brought to a definite end. In the investigated oligosaccharide-alditols N-glycoloylneuraminic acid (NeuGc) is in no case attached to galactose (Gal), but, if present, it is (alpha 2 leads to 6)-linked to N-acetylgalactosaminitol (GalNAc-ol).

Purification and properties of alpha-N-acetylgalactosaminidase from Clostridium perfringens

Exo-alpha-N-acetylgalactosaminidase has been purified 8000-fold from Clostridium perfringens by gel filtration, ion exchange chromatography, isoelectric precipitation, and negative adsorption on human O type erythrocytes. The resulting enzyme is active at physiological pH and temperature. Phenyl glycosides, oligosaccharides, mucins, glycolipids, and cell membranes are substrates for this enzyme. The result of enzyme action on blood type A erythrocytes is the loss of A activity and the simultaneous appearance of H activity, characteristic of the O blood group type. Polyacrylamide gel electrophoresis in sodium dodecyl sulfate demonstrates electrophoresis in sodium dodecyl sulfate demonstrates that the blood group A-destroying activity is distinct from the other glycosidase activities found in C. perfringens.

Sialic acid content of erythrocytes in normal individuals and patients with certain hematologic disorders

The sialic acid content of erythrocytes from healthy individuals of different blood types and of patients with known hematological disorders has been determined. The sialic acid was completely released enzymatically with sialidase and quantitated by the thiobarbituric acid method. The sialic acid content of erythrocytes was constant irrespective of ABO blood type, or anticoagulant used; viz, 0.85-0.92 mumoles/ml of packed erythrocytes or 46-53 X 10(6) sialyl residues per cell. Deviations from these normal values were obtained with erythrocytes from patients with a variety of hematological disorders. Patients with the following disorders have significantly (P less than 0.01) lower sialic acid values compared to erythrocytes from healthy individuals (given in the order of decreasing sialic acid content): sickle cell anemia, acute lymphocytic leukemia, chronic lymphocytic leukemia, acute myelomonocytic leukemia, non-Hodgkin lymphocytic lymphoma, chronic granulocytic leukemia, acute myelocytic leukemia, leukemia, and Hodgkin disease.

Resistance of red blood cell membrane to oxygen uptake

The apparent association velocity constant (k'c) was determined before and after disruption of the red blood cell membrane in one of several ways: 1) radiation of the cells using a 137Cs source did not significantly alter k'c (95 +/- 39.3 and 118 +/- 35.5 mM-1.s-1), 2) incubation of the cells with sialidase produced no change in k'c (112 +/- 42.6 and 123 +/- 46.8 mM-1.s-1), 3) using papain for the incubation similarly produced no significant alteration in k'c (94 +/- 21.2 and 113 +/- 51.8 mM-1.s-1), 4) a radiomimetic agent p-chloromercuribenzene sulfonate likewise produced no significant alteration in k'c (128 +/- 16.3 and 122 +/- 3.5 mM-1.s-1), and 5) employing phospholipase C to disrupt the membrane k'c did not significantly change (115 +/- 15.3 and 112 +/- 8.7 mM-1.s-1). We conclude that either O2 traverses the membrane in a manner uninfluenced by the manipulations here employed, or that the membrane offers no significant resistance to the speed of O2 uptake.

Antibodies that define NANA-independent MN-system antigens

The hemagglutinating properties of a large proportion of anti-M and anti-N reagents, and sera containing antibodies to MN-related antigens, have been shown to be unaffected by treatment of red blood cells with neuraminidase. These antibodies, which define NANA-independent MN-system structures, provide further evidence that MN blood group specificity may also be determined by moieties other than N-acetylneuraminic acid.