Anti‐Citrullinated Peptide Antibodies in Sudanese Patients with Leishmania donovani Infection Exhibit Reactivity not Dependent on Citrullination

African patients with Leishmania donovani infections have signs of strong systemic inflammation and high levels of circulating immune complexes (IC) and rheumatoid factor (RF), all serologic markers of rheumatic disease. As inflammation in general is associated with citrullination, we sought to investigate ACPA responses in Sudanese Leishmania patients. Serum samples were collected from Sudanese patients with visceral leishmaniasis (VL) and post‐kala‐azar dermal leishmaniasis (PKDL) as well as from ACPA‐positive Sudanese rheumatoid arthritis patients and compared to healthy Sudanese controls. Levels of circulating C1q‐binding IC and anticyclic citrullinated peptide 2(CCP2) were investigated using ELISA, and RF was measured with nephelometry. C1q adsorption was carried out to investigate anti‐CCP2 content in IC. Citrulline specificity was evaluated with control plates with cyclic arginine‐containing control peptides. Leishmania‐infected patients had elevated levels of RF and circulating IC but also a significant increase in anti‐CCP2 (12%) as compared to healthy controls. Anti‐CCP2‐positive Leishmania patients displayed lower anti‐CCP2 levels than Sudanese patients with rheumatoid arthritis (RA), and anti‐CCP2 levels in Leishmania patients showed a continuum not resembling the dichotomous pattern seen in patients with RA. Whereas the anti‐CCP reactivity of Sudanese RA sera was strictly citrulline dependent, anti‐CCP2‐positive Leishmania sera reacted equally well with ELISA plates containing arginine control peptides. There was a strong correlation between anti‐CCP2 and circulating IC among the Leishmania patients, but IC depletion only marginally diminished anti‐CCP2 levels. Our findings stress the importance to interpret a positive CCP test carefully when evaluated in non‐rheumatic conditions associated with macrophage activation.     

Microcirculation of skeletal muscle adapts differently to a resistive exercise intervention with and without superimposed whole‐body vibrations

Whole‐body vibration (WBV) training is commonly practiced and may enhance peripheral blood flow. Here, we investigated muscle morphology and acute microcirculatory responses before and after a 6‐week resistive exercise training intervention without (RE) or with (RVE) simultaneous whole‐body vibrations (20 Hz, 6 mm peak‐to‐peak amplitude) in 26 healthy men in a randomized, controlled parallel‐design study. Total haemoglobin (tHb) and tissue oxygenation index (TOI) were measured in gastrocnemius muscle (GM) with near‐infrared spectroscopy (NIRS). Whole‐body oxygen consumption (VO₂) was measured via spirometry, and skeletal muscle morphology was determined in soleus (SOL) muscle biopsies. Our data reveal that exercise‐induced muscle deoxygenation both before and after 6 weeks training was similar in RE and RVE (P = 0·76), although VO₂ was 20% higher in the RVE group (P<0·001). The RVE group showed a 14%‐point increase in reactive hyperaemia (P = 0·007) and a 27% increase in blood volume (P<0·01) in GM after 6 weeks of training. The number of capillaries around fibres was increased by 15% after 6 weeks training in both groups (P<0·001) with no specific effect of superimposed WBV (P = 0·61). Neither of the training regimens induced fibre hypertrophy in SOL. The present findings suggest an increased blood volume and vasodilator response in GM as an adaptation to long‐term RVE, which was not observed after RE alone. We conclude that RVE training enhances vasodilation of small arterioles and possibly capillaries. This effect might be advantageous for muscle thermoregulation and the delivery of oxygen and nutrients to exercising muscle and removal of carbon dioxide and metabolites.     

Epidemiology of adult ankle fractures in Sweden between 1987 and 2004: a population-based study of 91,410 Swedish inpatients

Background and purpose

Previous national epidemiological data on the characteristics and trends of patients with ankle fractures have been limited. We therefore analyzed data on Swedish inpatients with ankle fractures in this nationwide population study, based on data from 1987 through 2004.

Patients and methods

Data on all inpatients aged 15 years and older with ankle fracture were extracted from the Swedish National Patient Register for the period 1987–2004.

Results

We identified 91,410 hospital admissions with ankle fracture, corresponding to an annual incidence rate of 71 per 10⁵ person-years. During the study period, the number of hospital admissions increased by 0.2% annually, mainly from increase in fracture incidence in the elderly women. Mean age at admission was 45 (SD 19) years for men and 58 (18) for women. The major mechanism of injury was falling at the same level (64%).

Interpretation

This nationwide study of inpatients with ankle fractures showed an increase in fracture incidence, particularly in elderly women.Ankle fractures are among the most common fractures treated in orthopaedic surgery today. They are also a significant source of morbidity in both the young and the elderly (Donaldson et al. 1990, Jones et al. 1994, van Staa et al. 2001). Previous epidemiological studies have shown trends of increasing incidence over time, mainly in elderly women (Bengnér et al. 1986, Daly et al. 1987, Baron et al. 1996, Kannus et al. 1996, Court-Brown et al. 1998, van Staa et al. 2001, Kannus et al. 2002). However, most of these studies have included limited numbers of patients, and mostly originated from single hospitals or limited areas.Basic epidemiological data such as incidence, fracture type, age and sex distribution, mechanisms of injury, and surgical procedures can provide estimates when discussing disease burden and in the planning and provision of healthcare.The purpose of this study was to perform an epidemiological analysis of all adult ankle fractures requiring hospital admission in Sweden from 1997 through 2004, including incidence, causes of fracture, surgical procedures, patient characteristics, and trends over time.