Antiphospholipid antibody-induced cellular responses depend on epitope specificity : implications for treatment of antiphospholipid syndrome.

Essentials Antiphospholipid antibodies (aPL) are heterogeneous and induce different cellular responses. We analyzed signaling events induced by different monoclonal and patient aPL in monocytes. Two major signaling pathways involving either NADPH-oxidase or LRP8 were identified. Our data suggest that these two pathways mediate the majority of aPL effects on monocytes. SUMMARY: Background Antiphospholipid antibodies (aPLs) contribute to the pathogenesis of the antiphospholipid syndrome (APS) by induction of an inflammatory and procoagulant state in different cell types, and several signaling pathways have been described. Objectives To investigate whether signaling depends on the epitope specificity of aPLs. Methods Cellular effects of three human monoclonal aPLs with distinctly different epitope specificities were analyzed in vitro. Expression of tumor necrosis factor-α mRNA by mouse and human monocytes was the major readout. Analysis included cells from genetically modified mice, and the use of specific inhibitors in human monocytes. Data were validated with IgG isolated from 20 APS patients. Results Cofactor-independent anticardiolipin aPLs activated monocytes by induction of endosomal NADPH oxidase. Activation could be blocked by hydroxychloroquine (HCQ). Anti-ß2 -glycoprotein I aPL activated monocytes by interacting with LDL receptor-related protein 8 (LRP8). This could be blocked by rapamycin. Analysis of 20 APS patients' IgG showed that all IgG fractions activated the same two pathways as the monoclonal aPL, depending on their epitope patterns as determined by ELISA. Monocyte activation by APS IgG could be blocked completely by HCQ and/or rapamycin, suggesting that in most, if not all, APS patients there is no other relevant signaling pathway. Conclusions aPLs activate two major proinflammatory signal transduction pathways, depending on their epitope specificity. HCQ and rapamycin, either alone or in combination, completely suppress signaling by APS IgG. These observations may provide a rationale for specific treatment of APS patients according to their aPL profile.

Pathogenesis of the antiphospholipid syndrome revisited: time to challenge the dogma.

For more than a decade the antiphospholipid syndrome (APS) has been reported to be caused mainly by antiphospholipid antibodies (aPL), which are not directed against phospholipids but against a complex of phospholipids and phospholipid binding proteins, so called cofactors (e.g. ß2-glycoprotein I [ß2GPI]). In fact, many researchers propose that the only relevant antigens in the APS are the cofactors themselves, with ß2GPI being the most important. Antibodies that bind to phospholipids in a cofactor-independent manner are considered insignificant for the pathogenesis of the APS. We review the evidence for this current pathophysiologic concept and argue that it has never been proven and is now clearly no longer tenable. First, there is undisputable evidence that cofactor-independent aPL are pathogenic and present in the blood of APS patients. Second, available epidemiologic and clinical studies do not support a dominant pathogenic role for anti-ß2GPI.

Cofactor-independent human antiphospholipid antibodies induce venous thrombosis in mice.

UNLABELLED: Essentials Cofactor-independent antiphospholipid antibodies (CI-aPL) are generally considered non-pathogenic. We analyzed the effects of human monoclonal CI-aPL in a mouse model of venous thrombosis. As shown in vitro, CI-aPL induce a procoagulant state in vivo by activation of endosomal NADPH-oxidase. Contrary to common belief, CI-aPL induce venous thrombosis in vivo. SUMMARY: Background There is general consensus that the antiphospholipid syndrome (APS) is caused by antiphospholipid antibodies (aPL) with antibodies against ß2-glycoprotein-I being the most relevant. aPL that bind phospholipids in the absence of protein cofactors are generally considered pathogenetically irrelevant. We showed that cofactor-independent human monoclonal aPL isolated from APS patients induce proinflammatory and procoagulant cellular responses by activating endosomal NADPH-oxidase 2 (NOX2). Similar aPL were detected in all IgG fractions from APS patients analyzed. Objectives We aimed to clarify if cofactor-independent aPL can be thrombogenic in vivo and, if so, whether these effects are mediated via activation of NOX2. Methods Two cofactor-independent human monoclonal aPL, HL5B and RR7F, were tested in a mouse model of venous thrombosis. Genetically modified mice and in vitro assays were used to delineate the mechanisms underlying thrombus induction. Results HL5B and RR7F dramatically accelerate thrombus formation in this mouse model. Thrombus formation depends on tissue factor activation. It cannot be induced in NOX2-deficient mice. Bone marrow chimeras of C57BL/6J mice reconstituted with NOX2-deficient bone marrow showed that leukocyte activation plays a major role in thrombus formation. Neither TLR4 signaling nor platelet activation by our aPL is required for venous thrombus formation. Conclusions Cofactor-independent aPL can induce thrombosis in vivo. This effect is mainly mediated by leukocyte activation, which depends on the previously described signal transduction via endosomal NOX2. Because most APS patients have been shown to harbor aPL with similar activity, our data are of general relevance for the APS.

Prevalence of obesity in Malta.

BACKGROUND: Obesity is a global epidemic with the Mediterranean island of Malta being no exception. The World Health Organization (WHO) has identified Malta as one of the European countries with the highest obesity prevalence. METHOD: A cross-sectional study was conducted (2014-2016) under the auspices of the University of Malta. The prevalence of overweight-obesity in Malta was calculated and then age stratified for comparisons with previous studies. RESULTS: The study identified 69.75% (95% CI: 68.32-71.18) of the Maltese population to be either overweight or obese. The men overweight/obese prevalence (76.28% 95% CI: 74.41-78.14) was statistically higher than that for women (63.06% 95% CI: 60.92-65.20) (p = 0.0001). Age stratification revealed that both genders had the highest overweight prevalence rates between 55 and 64 years (Men = 23.25% 95% CI: 20.43-26.33; Women = 24.68% 95% CI: 21.44-28.22). Men obesity prevalence rates were highest in the 35 to 44 years group (22.52% 95% CI: 19.65-25.68) while for women it was highest in the 55 to 64 years group (28.90%, 95% CI: 25.44-30.63). CONCLUSION: Over a 35-year period, an overall decrease in the normal and overweight BMI categories occurred with an increase in the prevalence of obesity. An exception was observed in the women, where the prevalence of normal BMI increased over this time period. Also, it appears that while the total population obesity prevalence increased (for 2016), a percentage of the women have shifted from an obese to an overweight status.

Diabetes, pre-diabetes and their risk factors in Malta: a study profile of national cross-sectional prevalence study.

BACKGROUND: Type 2 diabetes mellitus constitutes a global epidemic and a major burden on health care systems across the world. Prevention of this disease is essential, and the development of effective prevention strategies requires validated information on the disease burden and the risk factors. Embarking on a nationally representative cross-sectional study is challenging and costly. Few countries undertake this process regularly, if at all. METHOD: This paper sets out the evidence-based protocol of a recent cross-sectional study that was conducted in Malta. Data collection took place from November 2014 to January 2016. RESULTS: This study presents up-to-date national data on diabetes and its risk factors (such as obesity, smoking, physical activity and alcohol intake) that will soon be publicly available. CONCLUSION: This protocol was compiled so that the study can be replicated in other countries. The protocol contains step-by-step descriptions of the study design, including details on the population sampling, the permissions required and the validated measurement tools used.

Tuberculosis among undocumented boat migrants to Malta: implications for a migrant tuberculosis policy.

SETTING: Malta, 2002-2005. OBJECTIVES: To describe the demography and tuberculosis (TB) epidemiology of undocumented immigrants to Malta to tailor TB control strategies to this population. DESIGN: Retrospective population study of undocumented immigrants to Malta using national TB surveillance data. RESULTS: Overall, 85% (4570/5383) of undocumented immigrants were screened on entry using chest X-ray (CXR). Undocumented immigrants were mostly young adults aged 15-34 years (81%) and predominately male (86%), mostly originating from Africa (88%). On screening, 3.5% (160/4570) had CXR suggestive of TB, of whom 12.5% (20/160) had active TB. Using both active and passive surveillance, 33 cases of active TB were diagnosed in these immigrants, 94% of whom were diagnosed during their first 12 months of residence in Malta. Entry screening detected 61% (20/33) of cases (yield 0.44%). Of the total TB cases in Malta, the proportion of undocumented immigrants increased markedly from 33% in 2002 to 60% in 2005. The reported TB incidence among immigrants was 390/100,000 compared to 2.1/100,000 in the Malta-born. CONCLUSION: Tailoring TB control strategies to this migrant population is essential for TB control in Malta. Awareness of increased risk of TB needs to be ongoing, not just at entry but for many years after arrival, even in resettlement countries.

Ankle-brachial index in a type 2 diabetic population with proliferative retinopathy: associated risk factors and complications.

AIM: The aim of this study was to analyse risk factors and complications associated with low ankle-brachial index (ABI) in a type 2 diabetic population with proliferative retinopathy. METHODS: This study included 181 subjects. ABI was measured with a Doppler device. Subjects with ABI <0.9 were diagnosed with peripheral vascular disease (PVD). The exclusion criterion was medial arterial calcification. RESULTS: The mean (± SD) age and diabetes (DM) duration were 65±9.7 years and 18.6±9.1 years, respectively. ABI <0.9 was associated with increasing age (P<0.001), DM duration (P=0.02), higher total (P=0.02) and LDL cholesterol (P=0.035), higher ESR (P=0.04), uric acid (P=0.004) vibration perception thresholds (VPT), and lower eGFR (P<0.001). BMI (P<0.001), waist index (P=0.01), FPG (P=0.013), HbA1c (P=0.005) and ALT (P<0.001) were significantly lower in patients with PVD. Multivariate analysis revealed age (P=0.04), high total cholesterol (P=0.038), low BMI (P=0.017), low VPT (P=0 031) and declining eGFR (p=0.006) to be independent predictors of PVD. CONCLUSION: Increasing age, total cholesterol levels, and VPT, together with declining renal function and lower BMI are independent predictors of PVD in a type 2 diabetic population with advanced microvascular disease. Knowledge of risk factors will help target preventive measures and treatment to subjects most susceptible to PVD.

Development and validation of a screening questionnaire for noise-induced hearing loss.

BACKGROUND: An audiometric health surveillance programme can be perceived to be a relatively costly exercise and employers, especially in developing countries, might therefore be reluctant to undertake this. A questionnaire might be a cheaper alternative. AIMS: To develop a questionnaire to help determine the prevalence of noise-induced hearing loss (NIHL) in the vernacular (language) of a developing country and to validate it against an audiometric standard. METHODS: A questionnaire was developed, translated and administered in a face-to-face interview. Otoscopic examination was followed by conventional pure-tone audiometry (at 0.25, 0.5, 1, 2, 4 and 8 kHz) for both ears of each respondent. The questionnaire responses were compared to the audiometric standard. RESULTS: Two hundred and fifty workers from three companies (two printing and one woodworking) participated in this study. The sensitivity of the hearing loss questionnaire in detecting noise-induced hearing loss was 32%, while its specificity was 79%. There was an evidence to suggest good agreement (r = 0.523) between the total number of years worked in noisy jobs and NIHL (P < 0.05). CONCLUSIONS: The questionnaire developed in this study was found to have an unacceptably low sensitivity for noise-induced hearing loss and therefore cannot be a valid substitute for audiometry. Pure tone industrial audiometry needs to be used more widely than currently in developing countries.

Intervertebral disc height correlates with vertebral body T-scores in premenopausal and postmenopausal women.

OBJECTIVE: To assess the correlation between vertebral body T-score and intervertebral disc height in premenopausal and postmenopausal women. METHODS: A total of 203 women were recruited from a large bone densitometer directory. The disc heights measured were those between the 12th thoracic and third lumbar vertebra. The discs were assigned the symbols D, whereby D1 applies for the disc between the 12th thoracic and first lumbar vertebra. The disc height of the group of women (n=38) with osteoporotic vertebral fractures was compared with the disc heights of hormone-treated women (n=47), untreated postmenopausal women (n=77) and another group of premenopausal women (n=41). Bone density measurements were taken by a Norland Bone Densitometer (DEXA 586). RESULTS: The lowest disc heights were found in the fracture group. The total disc height in the fracture group was 1.42+/-0.25 cm, significantly lower (P<0.0001) than the untreated group (1.82+/-0.3 cm), which in turn was significantly (P<0.0001) lower than the hormone-treated group (2.2+/-0.26 cm) and the premenopausal group (2.11+/-0.21 cm). The lowest T-scores were also noted in the vertebral fracture group (T-score=-3.1+/-0.3) (P<0.0001). The highest T-score recorded for the premenopausal group was -0.38+/-45, higher than that of the untreated menopausal -1.4+/-0.32 and hormone treated women -0.65+/-0.3, all three significantly higher than the fracture group (P<0.0001). The lowest T-scores were also noted in the vertebral fracture group (T-score=-3.1+/-0.3) (P<0.0001). The highest T-score recorded for the premenopausal group was -0.38+/-45, higher than that of the untreated menopausal -1.4+/-0.32 and hormone treated women -0.65+/-0.3, all three significantly higher than the fracture group (P<0.0001). Bone density across all groups revealed a correlation with disc height (R=0.29) (P<0.05). The group with vertebral osteoporotic fractures was the only group to show a negative correlation (-0.21) between disc height and vertebral bone density. Conversely, a significant correlation (R=0.47) (P<0.001) between the T-score and the total lumbar intervertebral disc height was noted in the premenopausal group of women. The menopausal group of untreated women also showed a significant correlation between the T-score and disc height (R=0.25 P<0.05); however, an insignificant positive correlation was found in the hormone-treated group. CONCLUSION: The fracture group was noted to have the lowest intervertebral disc height and lowest T-scores compared with the other three groups. The hormone-treated and the premenopausal women had the highest disc heights and T-scores recorded. Positive correlations between T-score and disc height were noted for all the groups except for the fracture group. These results suggest a coupling between the vertebral body and intervertebral disc, which if disrupted may lead to increased risk for fracture. The combination of both T-score and disc height may improve the screening sensitivity for vertebral body fracture risk.

Is erectile dysfunction a sentinel symptom for cardiovascular autonomic neuropathy in patients with type 2 diabetes?

The study investigated whether there is a significant association between erectile dysfunction (ED) secondary to autonomic failure, and cardiovascular autonomic neuropathy (CAN) in male patients suffering from type 2 diabetes. Twenty-two patients suffering from type 2 diabetes were recruited for this study after satisfying the stringent exclusion criteria used in the first stage. They had no evidence of overt cardiovascular disease, hypertension, neurological, renal or thyroid disease. Each subject was assessed for ED and CAN using standardized tests. Six patients were suffering from CAN while 10 patients were suffering from ED. There was no significant association between CAN and autonomic ED (P = 1). Three patients with normal erectile function had CAN, whilst three patients with ED had CAN. Further analysis demonstrates a significant increase in association between ED and CAN with age (P = 0.036). These results show that ED secondary to autonomic neuropathy is not significantly associated with CAN in this specific group of patients. Nonetheless, the study reveals that ED is a sentinel symptom for future development of CAN.

General practitioners role in the notification of communicable diseases - study in Malta.

General practitioners (GPs) have an essential role in notification of communicable diseases. The main aim of the study described here was to assess the GPs' awareness of and attitudes towards the notification system in Malta, with special focus on infectious intestinal disease (IID). A questionnaire collecting demographic data, information on reporting practices, opinions on the existing notification system and suggestions for improvement was sent to 256 GPs working in either private or public health sector. In all, 150 GPs took part in the survey (response rate 58.6%). The responses revealed that Maltese GPs were aware of their obligations to notify communicable diseases but often did not report them, relying on the hospitals or laboratories to do so. The Disease Surveillance Unit (DSU) website and medical school training were the main sources of information on notification. Notification forms were obtained from health centres and usually kept at the place of work. Most GPs reported filling in the forms during the patients' visits. Private GPs tended to notify earlier than GPs working in public health centers. Among IID, food-borne illness was reported more frequently than person-to-person transmitted gastroenteritis and was considered to be of a higher priority with regard to public health importance (p<0.001). The survey highlighted also some areas for improvement, including need of feedback especially by direct communication or a newsletter.

Sentinel Surveillance: an option for surveillance of infectious intestinal disease.

Sentinel surveillance systems offer advantages over passive surveillance which is known to have limitations due to incomplete reporting. Sentinel surveillance gathering data from selected sources was piloted as an option for surveillance of infectious intestinal disease (IID) in Malta. Between October 2004 and May 2005, 22 general practitioners (GPs) voluntarily participated in the study and reported on the number of IID cases (by age and sex) and all primary care encounters in their practice. The GPs' reporting activity lasted for 35 weeks, covering a total of 55,425 primary care encounters, of which 1.95% concerned IID. For every case reported via the routine passive notification system, seven cases would be picked up by this enhanced sentinel surveillance.

Low intervertebral disc height in postmenopausal women with osteoporotic vertebral fractures compared to hormone-treated and untreated postmenopausal women and premenopausal women without fractures.

OBJECTIVE: To assess the intervertebral disc height in postmenopausal women with osteoporotic vertebral fractures. METHODS: A total of 203 women were recruited from a bone densitometer directory. The disc heights measured were those between the 12th thoracic and 3rd lumbar vertebrae. The discs were assigned the symbols D, whereby D(1) refers to the disc between the 12th thoracic and 1st lumbar vertebrae. The disc height of the group of women (n = 38) with osteoporotic vertebral fractures was compared to the disc heights of hormone-treated women (n = 47), untreated postmenopausal women (n = 77) and another group of premenopausal women (n = 41). RESULTS: The total disc height (D(1) - D(3)) (mean +/- standard deviation) in the fracture group was 1.58 +/- 0.1 cm, significantly lower (p < 0.0001) than in the untreated group (1.82 +/- 0.06 cm), which in turn was significantly (p < 0.0001) lower than in the hormone-treated group (2.15 +/- 0.08 cm) and in the premenopausal group (2.01 +/- 0.09 cm). CONCLUSION: The fracture group was noted to have the lowest intervertebral disc height compared to the other three groups. The hormone-treated and the premenopausal women had the highest disc heights recorded. These results may be due to the effect that the menopause and senescence have on the discal connective tissue components. This may lead to loss of the shock-absorbing properties of the intervertebral disc and an altered discoid shape, influencing the occurrence of osteoporotic vertebral body fractures.

Estimating the burden and cost of infectious intestinal disease in the Maltese community.

The aim of this study was to estimate the burden of infectious intestinal disease (IID) and cost of illness at the community level from a societal aspect. A retrospective, age-stratified cross-sectional telephone study was carried out in Malta in 2004-2005. The number of cases, resources used and cost of resources were computed. The resources involved direct costs (health-care services, stool culture tests, medicines and personal costs) and indirect costs (costs from lost employment by cases and caregivers). This study estimated 0.421 (95% CI 0.092-0.771) separate episodes of IID per person per year in Malta which corresponds to 164 471 (95% CI 35 941-301 205) episodes of IID per year or 450 (95% CI 98-825) episodes of IID each day. The largest proportion of cost is due to provision of health-care services with euro10 454 901 [Maltese liri (Lm) 4 558 970] per year; followed by euro963 295 (Lm 2 209 393) in lost productivity; euro1 286 286 (Lm 561 078) in medicines; euro152 335 (Lm 66 452) in stool culture testing and euro71 487 (Lm 31 183) in personal costs, giving a total cost of illness of over euro16 million (7 million Lm) per year. The burden and cost of IID are high enough to justify efforts to control the illness. Such estimates are important to assess the cost-effectiveness of proposed specific interventions.

The magnitude and distribution of infectious intestinal disease in Malta: a population-based study.

Routine sources of information on infectious intestinal disease (IID) capture a fraction of the actual disease burden. Population studies are required to measure the burden of illness. A retrospective age-stratified cross-sectional telephone study was carried out in Malta in order to estimate the magnitude and distribution of IID at population level. A random sample of 3504 persons was interviewed by a structured questionnaire between April 2004 and December 2005. The response rate was 99.7%. From the study, the observed standardized monthly prevalence was 3.18% (95% CI 0.7-5.74) with 0.421 (95% CI 0.092-0.771) episodes of IID per person per year. The monthly prevalence was higher in the <5 years age group and in females aged 31-44 years. The mean duration of illness was 6.8 days and a median duration of 3 days. A bimodal seasonal distribution was observed with peaks in June-July and October-November.

Hypoventilation in chronic mountain sickness: a mechanism to preserve energy.

Chronic Mountain Sickness (CMS) patients have repeatedly been found to hypoventilate. Low saturation in CMS is attributed to hypoventilation. Although this observation seems logical, a further understanding of the exact mechanism of hypoxia is mandatory. An exercise study using the Bruce Protocol in CMS (n = 13) compared to normals N (n = 17), measuring ventilation (VE), pulse (P), and saturation by pulse oximetry (SaO(2)) was performed. Ventilation at rest while standing, prior to exercise in a treadmill was indeed lower in CMS (8.37 l/min compared with 9.54 l/min in N). However, during exercise, stage one through four, ventilation and cardiac frequency both remained higher than in N. In spite of this, SaO(2) gradually decreased. Although CMS subjects increased ventilation and heart rate more than N, saturation was not sustained, suggesting respiratory insufficiency. The degree of veno-arterial shunting of blood is obviously higher in the CMS patients both at rest and during exercise as judged from the SaO(2) values. The higher shunt fraction is due probably to a larger degree of trapped air in the lungs with uneven ventilation of the CMS patients. One can infer that hypoventilation at rest is an energy saving mechanism of the pneumo-dynamic and hemo-dynamic pumps. Increased ventilation would achieve an unnecessary high SaO(2) at rest (low metabolism). This is particularly true during sleep.

A profile of invasive cutaneous malignant melanoma in Malta: 1993-2002.

BACKGROUND: The incidence of malignant melanoma of the skin has risen in every part of the world where reliable cancer registration data are found. OBJECTIVE: Our study aims to describe the changing incidence of and survival from invasive cutaneous malignant melanoma in Malta, by analysing the data from the 211 cases that were registered at the Malta National Cancer Registry between 1993 and 2002. RESULTS: The age standardized incidence rates for invasive cutaneous malignant melanoma rose from 3.7 per 100,000 population per year for males and 5.1 for females in the first 5-year period, to 8.0 per 100,000 population per year for males and 5.9 for females in the second 5-year period. In both sexes, numbers of thin (< or = 1.0 mm) invasive melanomas increased significantly between 1993 and 2002; males also registered a significant increase in intermediate-thickness (1.01-4.0 mm) melanomas. The increase in numbers of thin and intermediate-thickness melanomas between the two 5-year periods was greatest in patients aged 60 years and over. The overall absolute 5-year survival rate for the first period was 74% and for the second period 92%. CONCLUSION: Numbers of reported cases of invasive cutaneous malignant melanoma in Malta have more than doubled during the 10-year study period. This is mostly due to a marked rise in the diagnosis of thin melanomas in both sexes, occurring mainly in patients aged 60 years and over. As thin melanomas are of low metastasizing potential, this has resulted in an increase in survival between the two 5-year study periods.