Innovating immune tolerance induction for haemophilia.

INTRODUCTION: Haemophilia A is an X-linked bleeding disorder characterized by a deficiency of coagulation protein factor VIII (FVIII). A challenging complication of therapeutic FVIII infusions is the formation of neutralizing alloantibodies against the FVIII protein defined as inhibitors. The development of FVIII inhibitors drastically alters the quality of life of the patients and is associated with tremendous increases in morbidity as well as treatment costs. AIM: Current clinical immune tolerance induction protocols to reverse inhibitors are lengthy, costly and not effective in all patients. Prophylactic protocols to prevent inhibitor formation have not yet been developed in the clinical setting. However, there has been ample progress towards this goal in recent years in preclinical studies using animal models of haemophilia. METHODS: Here, we review the mechanisms that lead to inhibitor formation against FVIII and two promising new strategies for antigen-specific tolerance induction. RESULTS: CD4+ T cells play an important role in the FVIII-specific B cell response. Immune tolerance can be induced based on transplacental delivery of FVIII domains fused to Fc or on oral delivery of leaf cells from chloroplast transgenic crop plants. CONCLUSIONS: Recent literature suggests that prophylactic tolerance induction protocols for FVIII may be feasible in haemophilia A patients.

Transfusion-transmitted hepatitis E in Germany, 2013.

The reported IgG seroprevalence against hepatitis E virus (HEV) in German blood donations is 6.8%, and HEV RNA detected in 0.08%, but documented evidence for HEV transmission is lacking. We identified two donations from a single donor containing 120 IU HEV RNA/mL plasma and 490 IU/mL. An infectious dose of 7,056 IU HEV RNA was transmitted via apheresis platelets to an immunosuppressed patient who developed chronic HEV. Further, transmission was probable in an immunocompetent child.

Evidence for gene transfer and expression of factor IX in haemophilia B patients treated with an AAV vector.

Pre-clinical studies in mice and haemophilic dogs have shown that introduction of an adeno-associated viral (AAV) vector encoding blood coagulation factor IX (FIX) into skeletal muscle results in sustained expression of F.IX at levels sufficient to correct the haemophilic phenotype. On the basis of these data and additional pre-clinical studies demonstrating an absence of vector-related toxicity, we initiated a clinical study of intramuscular injection of an AAV vector expressing human F.IX in adults with severe haemophilia B. The study has a dose-escalation design, and all patients have now been enrolled in the initial dose cohort (2 x 10(11) vg/kg). Assessment in the first three patients of safety and gene transfer and expression show no evidence of germline transmission of vector sequences or formation of inhibitory antibodies against F.IX. We found that the vector sequences are present in muscle by PCR and Southern-blot analyses of muscle biopsies and we demonstrated expression of F.IX by immunohistochemistry. We observed modest changes in clinical endpoints including circulating levels of F.IX and frequency of FIX protein infusion. The evidence of gene expression at low doses of vector suggests that dose calculations based on animal data may have overestimated the amount of vector required to achieve therapeutic levels in humans, and that the approach offers the possibility of converting severe haemophilia B to a milder form of the disease.

Evaluation of hop performance in children with anterior cruciate ligament reconstruction using healthy reference data: A cross-sectional study.

BACKGROUND: Hop performance evaluation in children after anterior cruciate ligament (ACL) reconstruction may benefit from comparison to healthy controls. Thus, the purpose was to investigate the hop performance in children one year after ACL reconstruction with a comparison to healthy controls. METHODS: Hop performance data from children with ACL reconstruction one year post-surgery and healthy children were compared. Four one-legged hop test data were analyzed: 1) single hop (SH), 2) 6 m timed hop (6 m-timed), 3) triple hop (TH), and 4) cross-over hop (COH). Outcomes were the best result (longest/fastest hop) from each leg and limb asymmetry. Differences in hop performance between-limbs (operated versus non-operated) and between-groups were estimated. RESULTS: 98 children with ACL reconstruction and 290 healthy children were included. Few statistically significant group differences were observed. Girls with ACL reconstruction outperformed healthy controls in two tests on the operated leg SH, COH) and in three tests on the non-operated leg (SH, TH, COH). However, the girls performed 4-5% worse on the operated leg when compared to the non-operated leg in all hop tests. No statistically significant between-group differences in the limb asymmetry were found. CONCLUSION: The hop performance in children with ACL reconstruction one year post-surgery was largely comparable to the level of healthy controls. Despite this, we cannot exclude that neuromuscular deficits exist among the children with ACL reconstruction. The inclusion of a healthy control group for evaluating hop performance evoked complex findings regarding the ACL reconstructed girls. Thus, they may represent a selected group.

Investigation of liver-targeted peripheral focused ultrasound stimulation (pFUS) and its effect on glucose homeostasis and insulin resistance in type 2 diabetes mellitus: a proof of concept, phase 1 trial.

BACKGROUND: Mechanical waves produced by ultrasound pulses have been shown to activate mechanosensitive ion channels and modulate peripheral nerves. However, while peripheral ultrasound neuromodulation has been demonstrated in vitro and in pre-clinical models, there have been few reports of clinical tests. AIM: We modified a diagnostic imaging system for ultrasound neuromodulation in human subjects. We report the first safety and feasibility outcomes in subjects with type 2 diabetes (T2D) mellitus and discuss these outcomes in relation to previous pre-clinical results. DESIGN: The study was performed as an open label feasibility study to assess the effects of hepatic ultrasound (targeted to the porta hepatis) on glucometabolic parameters in subjects with T2D. Stimulation (peripheral focused ultrasound stimulation treatment) was performed for 3 days (i.e. 15 min per day), preceded by a baseline examination and followed by a 2-week observation period. METHODS: Multiple metabolic assays were employed including measures of fasting glucose and insulin, insulin resistance and glucose metabolism. The safety and tolerability were also assessed by monitoring adverse events, changes in vital signs, electrocardiogram parameters and clinical laboratory measures. RESULTS AND CONCLUSION: We report post-pFUS trends in several outcomes that were consistent with previous pre-clinical findings. Fasting insulin was lowered, resulting in a reduction of HOMA-IR scores (P-value 0.01; corrected Wilcoxon signed-rank test). Additional safety and exploratory markers demonstrated no device-related adverse impact of pFUS. Our findings demonstrate that pFUS represents a promising new treatment modality that could be used as a non-pharmaceutical adjunct or even alternative to current drug treatments in diabetes.

Long-term correction of canine hemophilia B by gene transfer of blood coagulation factor IX mediated by adeno-associated viral vector.

Hemophilia B is a severe X-linked bleeding diathesis caused by the absence of functional blood coagulation factor IX, and is an excellent candidate for treatment of a genetic disease by gene therapy. Using an adeno-associated viral vector, we demonstrate sustained expression (>17 months) of factor IX in a large-animal model at levels that would have a therapeutic effect in humans (up to 70 ng/ml, adequate to achieve phenotypic correction, in an animal injected with 8.5x10(12) vector particles/kg). The five hemophilia B dogs treated showed stable, vector dose-dependent partial correction of the whole blood clotting time and, at higher doses, of the activated partial thromboplastin time. In contrast to other viral gene delivery systems, this minimally invasive procedure, consisting of a series of percutaneous intramuscular injections at a single timepoint, was not associated with local or systemic toxicity. Efficient gene transfer to muscle was shown by immunofluorescence staining and DNA analysis of biopsied tissue. Immune responses against factor IX were either absent or transient. These data provide strong support for the feasibility of the approach for therapy of human subjects.

Progress and prospects: immune responses to viral vectors.

Viral vectors are potent gene delivery platforms used for the treatment of genetic and acquired diseases. However, just as viruses have evolved to infect cells efficiently, the immune system has evolved to fight off what it perceives as invading pathogens. Therefore, innate immunity and antigen-specific adaptive immune responses against vector-derived antigens reduce the efficacy and stability of in vivo gene transfer. In addition, a number of vectors are derived from parent viruses that humans encounter through natural infection, resulting in preexisting antibodies and possibly in memory responses against vector antigens. Similarly, antibody and T-cell responses may be directed against therapeutic gene products that often differ from the endogenous nonfunctional or absent protein that is being replaced. As details and mechanisms of such immune reactions are uncovered, novel strategies are being developed, and vectors are being specifically engineered to avoid, suppress or manipulate the response, ideally resulting in sustained expression and immune tolerance to the transgene product. This review provides a summary of our current knowledge of the interactions between the immune system adeno-associated virus, adenoviral and lentiviral vectors, and their transgene products.

Antacids and dietary supplements with an influence on the gastric pH increase the risk for food sensitization.

BACKGROUND: Elevation of the gastric pH increases the risk for sensitization against food allergens by hindering protein breakdown. This can be caused by acid-suppressing medication like sucralphate, H2-receptor blockers and proton pump inhibitors, as shown in recent murine experimental and human observational studies. OBJECTIVE: The aim of the present study was to assess the sensitization capacity of the dietary supplement base powder and of over-the-counter antacids. METHODS: Changes of the pH as well as of protein digestion due to base powder or antacids were measured in vitro. To examine the in vivo influence, BALB/c mice were fed codfish extract with one of the acid-suppressing substances. Read-out of antibody levels in the sera, of cytokine levels of stimulated splenocytes and of intradermal skin tests was performed. RESULTS: The pH of hydrochloric acid was substantially increased in vitro by base powder as well as antacids in a time- and dose-dependent manner. This elevation hindered the digestion of codfish proteins in vitro. A significant increase in codfish-specific IgE antibodies was found in the groups fed codfish combined with Rennie Antacidum or with base powder; the latter also showed significantly elevated IgG1 and IgG2a levels. The induction of an anaphylactic immune response was proven by positive results in intradermal skin tests. CONCLUSIONS: Antacids and dietary supplements influencing the gastric pH increase the risk for sensitization against allergenic food proteins. As these substances are commonly used in the general population without consulting a physician, our data may have a major practical and clinical impact.

Effect of repeated dose of erythromycin on the pharmacokinetics of roflumilast and roflumilast N-oxide.

OBJECTIVE: To investigate the effects of steady state erythromycin on the pharmacokinetics of roflumilast and its pharmacodynamically active metabolite roflumilast N-oxide in healthy subjects. Both roflumilast and roflumilast N-oxide have similar intrinsic PDE4 inhibitory activity; the total PDE4 inhibition (tPDE4i) in humans is likely due to the combined effect of roflumilast and roflumilast N-oxide. METHODS: Subjects (n = 16) received single oral roflumilast 500 microg once daily (Days 1 and 15), and repeated oral erythromycin 500 mg three times daily (Days 9 - 21). Percent ratios of Test/Reference (Reference: roflumilast alone; Test: roflumilast and steady-state erythromycin) were calculated for the geometric means and their 90% confidence intervals for systemic exposure (AUC), maximum concentration (Cmax) (roflumilast and roflumilast N-oxide), and apparent clearance of roflumilast. RESULTS: After co-administration of erythromycin and roflumilast, the mean AUC and Cmax of roflumilast increased by 70% and 40%, respectively. The mean apparent clearance of roflumilast decreased from 8.2 l/h (Reference) to 4.8 l/h (Test). Steady-state erythromycin did not alter the mean AUC of roflumilast N-oxide, however, the mean Cmax decreased by 34%. The AUCroflumilast N-oxide/AUCroflumilast ratio decreased from 10.6 (Reference) to 6.4 (Test). Co-administration of erythromycin and roflumilast did not influence the integrated total exposure to roflumilast and roflumilast N-oxide, i.e. mean tPDE4i. No clinically relevant adverse events were observed during the study. CONCLUSIONS: Co-administration of erythromycin (a moderate CYP3A4 inhibitor) and roflumilast does not require dose adjustment of roflumilast.

Combined oral administration of L-arginine and tetrahydrobiopterin in a rat model of pulmonary arterial hypertension.

Alterations in the nitric oxide (NO) pathway play a major role in pulmonary arterial hypertension (PAH). L-arginine (LA) and tetrahydrobiopterin (BH4) are main substrates in the production of NO, which mediates pulmonary vasodilation. Administration of either LA or BH4 decrease pulmonary artery pressure (PAP). A combined administration of both may have synergistic effects in the therapy of PAH. In a telemetrically monitored model of unilateral pneumonectomy and monocrotaline-induced PAH, male Sprague-Dawley rats received either LA (300 mg/kg; n = 15), BH4 (20 mg/kg; n = 15), the combination of LA and BH4 (300 mg/kg, 20 mg/kg; n = 15), or vehicle (control group; n = 10) from day 28 after monocrotaline induction. Therapy was orally administered once daily over consecutive 14 days. LA, BH4, or both equally lowered PAP, increased pulmonary vascular elasticity, restored spontaneous locomotoric activity, prevented body weight loss and palliated small vessel disease of severely pulmonary hypertensive rats. BH4 substitution lowered asymmetric dimethylarginine levels sustainably at 60 min after administration and downregulated endothelial NO synthase mRNA expression. No significant survival, macro- and histomorphologic or hemodynamic differences were found between therapy groups at the end of the study period. Administration of LA and BH4 both mediated a decrease of mean PAP, attenuated right ventricular hypertrophy and small vessel disease in monocrotaline-induced pulmonary hypertensive rats, though a combined administration of both substances did not reveal any synergistic therapy effects in our animal model.

[Ultrasound of the urinary system]. / Ecografía del aparato urinario.

Ultrasound techniques are able to provide a fairly complete examination of the urinary system, achieving a high sensitivity in relevant-pathology detection, especially in the kidney, bladder and prostate. Early detection of pathologies such as tumors or urinary tract obstructions, sometimes even before their clinical manifestation, has improved their management and prognosis in many cases. This, added to its low cost and harmlessness, makes ultrasound ideal for early approaches and follow-up of a wide number of urinary system pathologies. In this article, the ultrasound characteristics of the main urinary system pathologies that can be diagnosed by this technique, are reviewed.

Nav1.3 sodium channels: rapid repriming and slow closed-state inactivation display quantitative differences after expression in a mammalian cell line and in spinal sensory neurons.

Although rat brain Nav1.3 voltage-gated sodium channels have been expressed and studied in Xenopus oocytes, these channels have not been studied after their expression in mammalian cells. We characterized the properties of the rat brain Nav1.3 sodium channels expressed in human embryonic kidney (HEK) 293 cells. Nav1.3 channels generated fast-activating and fast-inactivating currents. Recovery from inactivation was relatively rapid at negative potentials (<-80 mV) but was slow at more positive potentials. Development of closed-state inactivation was slow, and, as predicted on this basis, Nav1.3 channels generated large ramp currents in response to slow depolarizations. Coexpression of beta3 subunits had small but significant effects on the kinetic and voltage-dependent properties of Nav1.3 currents in HEK 293 cells, but coexpression of beta1 and beta2 subunits had little or no effect on Nav1.3 properties. Nav1.3 channels, mutated to be tetrodotoxin-resistant (TTX-R), were expressed in SNS-null dorsal root ganglion (DRG) neurons via biolistics and were compared with the same construct expressed in HEK 293 cells. The voltage dependence of steady-state inactivation was approximately 7 mV more depolarized in SNS-null DRG neurons, demonstrating the importance of background cell type in determining physiological properties. Moreover, consistent with the idea that cellular factors can modulate the properties of Nav1.3, the repriming kinetics were twofold faster in the neurons than in the HEK 293 cells. The rapid repriming of Nav1.3 suggests that it contributes to the acceleration of repriming of TTX-sensitive (TTX-S) sodium currents that are seen after peripheral axotomy of DRG neurons. The relatively rapid recovery from inactivation and the slow closed-state inactivation kinetics of Nav1.3 channels suggest that neurons expressing Nav1.3 may exhibit a reduced threshold and/or a relatively high frequency of firing.

TSH-controlled L-thyroxine therapy reduces cholesterol levels and clinical symptoms in subclinical hypothyroidism: a double blind, placebo-controlled trial (Basel Thyroid Study).

This study evaluated the effect of physiological, TSH-guided, L-thyroxine treatment on serum lipids and clinical symptoms in patients with subclinical hypothyroidism. Sixty-six women with proven subclinical hypothyroidism (TSH, 11.7 +/- 0.8 mIU/liter) were randomly assigned to receive L-thyroxine or placebo for 48 wk. Individual L-thyroxine replacement (mean dose, 85.5 +/- 4.3 microg/d) was performed based on blinded TSH monitoring, resulting in euthyroid TSH levels (3.1 +/- 0.3 mIU/liter). Lipid concentrations and clinical scores were measured before and after treatment. Sixty-three of 66 patients completed the study. In the L-thyroxine group (n = 31) total cholesterol and low density lipoprotein cholesterol were significantly reduced [-0.24 mmol/liter, 3.8% (P = 0.015) and -0.33 mmol/liter, 8.2% (P = 0.004), respectively]. Low density lipoprotein cholesterol decrease was more pronounced in patients with TSH levels greater than 12 mIU/liter or elevated low density lipoprotein cholesterol levels at baseline. A significant decrease in apolipoprotein B-100 concentrations was observed (P = 0.037), whereas high density lipoprotein cholesterol, triglycerides, apolipoprotein AI, and lipoprotein(a) levels remained unchanged. Two clinical scores assessing symptoms and signs of hypothyroidism (Billewicz and Zulewski scores) improved significantly (P = 0.02). This is the first double blind study to show that physiological L-thyroxine replacement in patients with subclinical hypothyroidism has a beneficial effect on low density lipoprotein cholesterol levels and clinical symptoms of hypothyroidism. An important risk reduction of cardiovascular mortality of 9-31% can be estimated from the observed improvement in low density lipoprotein cholesterol.

Conjugal loss and syndromal depression in a sample of elders aged 70 years or older.

OBJECTIVE: The goal of this study was to describe the association between conjugal loss and both syndromal depression and depressive symptoms in a prospective cohort study of people aged 70 years or older. METHOD: A measure of syndromal depression, the shortform Composite International Diagnostic Interview (CIDI), and a revised version of the Center for Epidemiologic Studies--Depression Scale (CES-D Scale) were administered to a group of 5,449 elders in a longitudinal cohort study. The authors compared the rates of syndromal depression (CIDI diagnosis) and depressive symptoms (six CES-D Scale symptoms) in married participants and those who lost spouses between the first and second waves of assessment. RESULTS: The rate of syndromal depression in the newly bereaved was nearly nine times as high as the rate for married individuals, and the rate of depressive symptoms was nearly four times as high. The percentage of the bereaved respondents who had scores above threshold on the revised CES-D Scale was higher for those interviewed up to 2 years after loss of a spouse than for married respondents. Age, sex, prior psychiatric history, and the expectedness of the death did not differ between depressed and nondepressed newly bereaved subjects. CONCLUSIONS: Recent bereavement is a significant risk factor for syndromal depression in the elderly. Some widows and widowers experienced high levels of depressive symptoms up to 2 years after the loss of their spouses. Neither demographic variables nor variables concerning the nature of the spouse's death predicted bereavement-related depression.

Optimized production of high-titer recombinant adeno-associated virus in roller bottles.

Adeno-associated viral (AAV) vectors are used for in vivo gene transfer in a number of preclinical models of genetic diseases (including large-animal models) and are currently being tested in clinical trials for treatment of hemophilia B and cystic fibrosis. Protocols for production of AAV vectors in a helper virus-free system are available and are based on transient transfection of HEK-293 cells with multiple plasmids. Scale-up of vector production has been labor intensive and inefficient because of a lack of larger culture vessels suitable for growth of adherent cells, large-scale transfection, and vector production. Here we report efficient production of AAV vector in roller bottles, which represents a 10-fold scale-up from the conventional flask or plate method. Optimized production yielded greater than 10(13) vector genomes per bottle and was as cost effective as published protocols using plates. Successful vector production by this method was dependent on optimization of transfection by calcium phosphate precipitation, of monitoring of cell growth (by measurement of glucose consumption), of cell culture conditions, and CO2/air exchange with the culture vessel.

Gene therapy for hereditary hematological disorders.

The year 2000 saw the first successful treatment of a genetic disorder by gene therapy. Pediatric patients with X-linked severe combined immunodeficiency disorder (SCID-X1) received autologous CD34+ hematopoietic cells following ex vivo gene transfer using a retroviral vector, with subsequent demonstration of improved immune responses. A number of preclinical and clinical studies have been conducted with the aim of developing gene therapy for hemophilia, Fanconi anemia, sickle cell disease, beta-thalassemia, chronic granulomatous disease, and other inherited hematological disorders. The greatest advances in novel approaches toward treatment of hematological disorders have been made in hemophilia, with 3 current phase I clinical trials ongoing. Two trials are investigating the safety and feasibility of utilizing either an ex vivo, non-viral gene transfer technique or an intravenous infusion of a retroviral vector to treat adults with severe hemophilia A (factor VIII deficiency). The third study involves intramuscular administration of an adeno-associated viral (AAV) vector for expression of factor IX in adult patients with hemophilia B. Results from this study and from preclinical studies preceding the trial demonstrate that it is possible to safely administer high doses of a viral vector in vivo.

The role of cholecystokinin in radiographic opacification of the gallbladder.

Studies of the effect of cholecystokinin (CCK) on hepatic elimination of intravenously administered iopanoate and on gallbladder opacification were performed using nonoperated dogs with intact enterohepatic circulation and normal endogenous bile salt pool. Intravenous administration of CCK (3 units/kg) resulted in a 32% increase in apparent transport maximum (maximum rate of elimination) of iopanoate and earlier and enhanced gallbladder opacification. This increase in apparent transport maximum was abolished by cholecystectomy, indicating that the increase was a result of the release of bile salts from the gallbladder rather than a direct effect of the hormone on the hepatic elimination of iopanoate. The early gallbladder opacification and increased density of contrast material in the gallbladder were related to CCK-induced emptying of the gallbladder and subsequent filling with opacified bile.

Saturation kinetics of iopanoate in dogs with an intact enterohepatic circulation. Before and after phenobarbital induction.

Capacity-limited elimination of sodium iopanoate and a reproducible apparent transport maximum (Tm) were demonstrated in nonoperated dogs having an intact enterohepatic circulation and normal endogenous bile salt pool. Using a multiple infusion technique, estimation of apparent Tm of iopanoate in the liver was possible without sampling either bile or urine. Values obtained for apparent Tm of iopanoate in dogs with normal bile salt pool were similar to those obtained in studies of dogs with chronic bile fistulas. Use of this technique in 4 dogs demonstrated that pretreatment with phenobarbital significantly increases apparent Tm of iopanoate.

Megadose transplantation of purified peripheral blood CD34(+) progenitor cells from HLA-mismatched parental donors in children.

We performed HLA-mismatched stem cell transplantation with megadoses of purified positively selected mobilized peripheral blood CD34(+) progenitor cells (PBPC) from related adult donors in 39 children lacking an otherwise suitable donor. The patients received a mean number of 20.7 +/- 9.8 x 10(6)/kg purified CD34(+) and a mean number of 15.5 +/- 20.4 x 10(3)/kg CD3(+) T lymphocytes. The first seven patients received short term (<4 weeks) GVHD prophylaxis with cyclosporin A, whereas in all the following 32 patients no GVHD prophylaxis was used. In 38 evaluable patients, five patients experienced primary acute GVHD grade I and one patient grade II. In 32 patients, no signs of primary GVHD were seen and GVHD only occurred after T cell add backs. T cell reconstitution was more rapid if the number of transplanted CD34(+) cells exceeded 20 x 10(6)/kg. Of the 39 patients, 15 are alive and well, 13 died due to relapse and 10 transplant-related deaths occurred. We conclude that the HLA barrier can be overcome by transplantation of megadoses of highly purified mismatched CD34(+) stem cells. GVHD can be prevented without pharmacological immunosuppression by the efficient T cell depletion associated with the CD34(+) positive selection procedure. This approach offers a promising therapeutic option for every child without an otherwise suitable donor.

Memory complaint in a community sample aged 70 and older.

OBJECTIVES: The ability of older people to estimate their own memory, often referred to as "metamemory," has been evaluated in previous studies with conflicting reports regarding accuracy. Some studies have suggested that an older person's metamemory is mostly accurate, whereas others have demonstrated little relationship between memory complaint and actual impairment. This study examines memory complaint in a large national sample of older people aged > or = 70. DESIGN: A longitudinal cohort study with two waves of data collection spaced 2 years apart. SETTING: A nationwide random sample of community-dwelling older persons. PARTICIPANTS: A total of 5,444 community-dwelling persons aged > or = 70 and their spouses. MEASUREMENTS: Participants were asked if they believed their memory was excellent, very good, good, fair, or poor. They were then administered a cognitive assessment derived from the Mini-Mental Status Exam. RESULTS: In general, people's assessment of their memory corresponded with their actual performance on cognitive measures. However, large portions of the sample inaccurately assessed their memory skills. People who reported depressive symptoms and had impairment in activities of daily living were more likely to state that their memory was impaired, although they performed very well on cognitive measures. CONCLUSIONS: The conditions that skew people's self-assessment are the ones most likely to bring them into contact with healthcare professionals. This may give clinicians the general impression that older people cannot assess their own cognitive skills. However, poor metamemory appears to be a characteristic of a specific subgroup of older persons, not necessarily characteristic of the general population.