Disease severity of 100 patients with systemic sclerosis over a period of 14 years: using a modified Medsger scale

OBJECTIVE

To assess organ involvement according to a modified Medsger severity scale and its relation to outcome and prognosis in patients with systemic sclerosis.

METHODS

One hundred consecutive patients observed in Lund with systemic sclerosis were followed up for a period of 14 years. The mean follow up time was 7.7 years. Initial assessment and an annual evaluation was performed for each patient, with a mean visit frequency of 5.6 per patient.

RESULTS

Age at referral, high total skin score, truncal skin involvement, low vital capacity, low static lung compliance, low Cr-EDTA clearance, and ECG abnormalities at the initial assessment predict poor outcome. A severity scoring system for five organ systems indicates a slow progression of organ dysfunction after recruitment into the study. The female: male ratio was 2:1, the mean age at onset of symptoms was 42.3 (range 3-82), and the mean age at recruitment was 47.2 years (range 17-82). Thirty patients died during the follow up period at the mean age of 61.3 years (range 33-85). The causes of death were directly related to systemic sclerosis in at least 10 patients, infections in six, cancers in nine, and other causes in four patients. The standardised mortality ratio was 3.5 and 3.7 for men and women, respectively.

CONCLUSION

A high severity score for function of vital organs was shown to predict shortened survival. In this study a severity score based on simple clinical assessment variables was able to predict poor outcome from extensive skin changes, ECG changes, and compromised lung and renal function. Organ dysfunction mainly became manifest during the first five years of the disease, whereafter organ function remained largely stable.

Von Willebrand factor propeptide as a marker of disease activity in systemic sclerosis (scleroderma)

In 44 consecutive patients with systemic sclerosis (SSc), plasma concentrations of von Willebrand factor (vWf) were higher than those of the vWf propeptide, but the propeptide showed less variability within patient subgroups. Higher values of the propeptide were observed in patients with early pulmonary involvement. A closer correlation of the propeptide than of vWf to biochemical markers of activity was also evident. Our results suggest that the propeptide, despite a shorter circulating half-time and lower plasma concentrations than vWf, is more useful in the assessment of disease activity in SSc.

Longitudinal study of methylmercury and inorganic mercury in blood and urine of pregnant and lactating women, as well as in umbilical cord blood

We have investigated exposure to methylmercury (MeHg) and mercury vapor (Hg0) in pregnant women and their newborns in Stockholm. The women were followed for 15 months post delivery. MeHg, inorganic Hg (I-Hg), and total Hg (T-Hg) in maternal and cord blood were determined by automated alkaline solubilization/reduction and cold vapor atomic fluorescence spectrometry. T-Hg in urine was determined by inductively coupled plasma mass spectrometry. About 72% of the Hg in blood (n = 148) in early pregnancy was MeHg (median 0.94 microg/L, maximum 6.8 microg/L). Blood MeHg decreased during pregnancy, partly due to decreased intake of fish in accordance with recommendations to not eat certain predatory fish during pregnancy. Cord blood MeHg (median 1.4 microg/L, maximum 4.8 microg/L) was almost twice that in maternal blood in late pregnancy and was probably influenced by maternal MeHg exposure earlier and before pregnancy. Blood I-Hg (median 0.37 microg/L, maximum 4.2 microg/L) and urine T-Hg (median 1.6 microg/L, maximum 12 microg/L) in early pregnancy were highly correlated, and both were associated with the number of amalgam fillings. The concentrations decreased during lactation, probably due to excretion in milk. Cord blood I-Hg was correlated with that in maternal blood. The results show the importance of speciation of Hg in blood for evaluation of exposure and health risks.

Circulating collagen metabolites in systemic sclerosis. Differences between limited and diffuse form and relationship with pulmonary involvement

OBJECTIVE

To study collagen metabolites in systemic sclerosis (SSc) and their relationship with clinical manifestations of the disease.

METHODS

Forty-eight SSc patients, 13 with a diffuse form (dcSSc), 23 with a limited form (lcSSc) and 12 with suspected SSc not fulfilling the ACR criteria, and 31 healthy controls were examined. Serum concentrations of aminoterminal type III procollagen peptide (PIIINP), aminoterminal and carboxyterminal type I procollagen peptides (PINP and PICP) and cross-linked carboxyterminal telopeptide of collagen I (ICTP) were determined by radioimmunoassay.

RESULTS

Increased serum concentrations of ICTP were found in SSc patients compared with controls. Distinctly higher levels of ICTP were observed in dcSSc than in lcSSc. High serum ICTP was correlated with skin score and acute phase reactants, and with reduced pulmonary function. Serum PIIINP concentration was elevated in both lcSSc and dcSSc.

CONCLUSION

Augmented collagen catabolism accompanies the increased collagen synthesis in SSc. Serum ICTP concentration is a marker of this feature and also reflects clinical severity.

Rapid polarization of Th2 cells during induction of antigen-specific IgE antibodies in vitro

BACKGROUND

Type 2 T-helper cells (Th2) are involved in the regulation of the humoral immune response against antigens and allergens and directly affect which isotype will be produced. The mechanism that regulates antigen-specific IgE secretion and immune deviation is still not known.

OBJECTIVES

To delineate mechanisms behind antigen-specific IgE secretion we have used in vitro immunization and focused on T-cell phenotype and the activation status of the transcription factor NFkappaB.

METHODS

Peripheral blood lymphocytes (PBMC) from seronegative donors were immunized in vitro with a peptide consisting of both a T-cell and a B-cell epitope.

RESULTS

Antigen-specific IgE antibodies could be detected after a primary immunization, during which T-helper cells secreted type 2 cytokines. Specific IgE was also detected in the secondary immunization, but due to a rapid polarization from Th2 to Th1 phenotype, exogenous IL-4 was required for the specific IgE secretion. Analysis of NFkappaB activation in B and T cells during primary and secondary immunization showed that NFkappaB could be detected in both B and T cells during primary immunization, but was dependent on exogenous IL-4 in the secondary immunization.

CONCLUSION

This is the first evidence of antigen-specific IgE induction in vitro using naive B cells, demonstrating the involvement of T-helper cell phenotype and NFkappaB and demonstrates the usefulness of in vitro cultures to study the effect of antigens on human immunocytes.

Phlebotomy increases cadmium uptake in hemochromatosis

The intestinal absorption of the nephrotoxic environmental pollutant cadmium increases markedly when iron stores are depleted. This may be mediated by an up regulation of the recently identified mucosal transporter DMT1 (Nramp2 or DCT1) for divalent cations. We tested whether the highly increased iron absorption in hereditary hemochromatosis (HH) was accompanied by an enhanced absorption of cadmium and lead. Cadmium and lead in blood and iron status markers were determined in 21 nonsmoking subjects with HH genetically tested for the HFE mutations and in 21 nonsmoking controls matched for age and sex. In subjects with HH on maintenance phlebotomy treatment, blood concentrations of cadmium, but not lead, were significantly higher than in paired controls. There was a strong age-independent positive association between blood cadmium and the number of years of phlebotomy treatment. Blood lead showed a similar but less pronounced consequence of treatment. All HH subjects with lower blood cadmium than the corresponding controls had either no mutation in the HFE gene, were not phlebotomized, or were phlebotomized for only a limited time. Our findings indicate that the treatment rather than the disease increased the cadmium uptake in homozygous HH. Further studies are needed to confirm whether the disease decreased cadmium absorption and whether the absorption was dependent on the genotype.

Metal-bone interactions

Recent studies indicate that lead and cadmium may exert both direct and indirect actions on bone turnover, indirectly via kidney dysfunction, and directly on osteoblast and osteoclast function. Increased blood lead concentrations, most likely as a result of an increased bone turnover, have been detected in pregnant, lactating, and menopausal women. Lead exposure has also been negatively associated with children's growth in stature. Both lead and cadmium are nephrotoxic and can disturb vitamin D metabolism. Cadmium has been shown to induce kidney damage and osteoporosis/osteomalacia at long-term high-level exposure. A negative association between cadmium dose and bone mass has recently been detected in both occupationally and environmentally exposed people at relatively low cadmium exposure.

Toxic and essential elements in placentas of Swedish women

OBJECTIVES

To evaluate interactions between toxic and essential elements in the mother-fetus relationship and possible predictors of trace element concentrations in placenta and cord blood.

DESIGN AND METHODS

A group of 106 Swedish women was investigated for concentrations of cadmium, lead, and several essential elements in placenta as well as cadmium, lead, zinc, and selenium in venous blood collected at gestational week (gw) 36 and umbilical cord blood. Relations between these elements and maternal and child's characteristics were examined.

RESULTS

The concentrations of cadmium in placenta ranged from 10 to 170 nmol/kg, with the median value (Md) being 46 nmol/kg. Cord blood cadmium (Md of 0.19 nmol/L) was only about 10% of that in maternal blood. Smokers had significantly higher cadmium concentrations in blood (p < 0.001) and placenta (p = 0.001) than non-smokers. The median placental concentration of lead was 26 nmol/kg (range 0-630 nmol/kg). The lead levels in cord blood (Md of 54 nmol/L) were almost the same as in maternal blood. Statistically significant negative associations were found between cord blood lead, on one hand, and child's weight, length, and head circumference, on the other. The placental levels (medians and ranges) of the essential elements (micromol/kg) were 160 (120-280) for zinc, 2.4 (2.0-3.3) for selenium, 15 (10-20) for copper, 0.084 (0.02-0.32) for cobalt, 0.055 (0.03-0.12) for molybdenum, and 1.2 (0. 65-5.1) for manganese, respectively. Several of the essential elements in placenta correlated significantly with each other. Multiparous mothers had significantly lower concentrations of zinc (p = 0.002) and selenium (p = 0.049) in serum as well as zinc (p = 0. 001) and calcium (p = 0.004) in placenta than nulliparous ones. Also, cord blood zinc decreased with parity.

CONCLUSIONS

The results showed that lead, but not cadmium crossed easily the placental barrier. There were no negative effects of cadmium on the zinc status. Cord blood lead, on the other hand, was a negative predictor of child's birth weight, length and head circumference, indicating that lead might have negative influence on growth in children even at very low exposure levels. There was a depletion of maternal stores of essential elements with increasing parity.

Interferon-alpha and ribavirin treatment of hepatitis C in children with malignancy in remission

Twenty-eight cases of hepatitis C virus (HCV) infection were identified in children in a pediatric oncology ward during 2 nosocomial outbreaks. HCV infection spontaneously cleared in 6 patients (21%). Eleven patients with persistent HCV viremia who had malignant diseases in remission after treatment were given a 48-week course of combined therapy with interferon-alpha (5x106 U 3 times weekly) and oral ribavirin (15 mg/kg/d). Seven (64%) of the 11 patients had sustained virological responses 6 and 12 months after cessation of therapy. Side effects were common but generally were mild or moderate.

A disease severity scale for systemic sclerosis: development and testing

OBJECTIVE

To develop and test a severity scale for individual organ involvements in systemic sclerosis (SSc, scleroderma).

METHODS

An international study group completed the following tasks: (1) developed a glossary of terms including all pertinent variables for 9 potentially affected organ systems; (2) collected prospective data to determine the feasibility and practicality of each proposed variable; (3) revised the initial list of variables; (4) determined the association of each variable with mortality (a proxy for morbidity) using 579 patients in an existing comprehensive longitudinal scleroderma databank; (5) developed a severity grading scale for each organ system by discussion and consensus; and (6) externally validated the scale using an independent group of 680 patients from the same databank.

RESULTS

Nine organ-specific severity scales were developed from 0 (no documented involvement) to 4 (endstage disease). The data required for scale completion are relatively easy and practical for all physicians to obtain.

CONCLUSION

This preliminary severity scale will be useful for assessing disease severity status in individual patients both at one point in time and longitudinally. The severity scale will assist in the design and conduct of clinical trials and the comparison of study populations with one another. The scale will serve as a framework for developing a scleroderma disease activity index.

Evaluation of kits for measurement of the soluble transferrin receptor

Three commercially available kits for determination of the soluble serum transferrin receptor (sTfR), R&D Systems, UK, Ramco Laboratories, USA and Orion, Finland were compared with respect to practicability, comparability and ability to discriminate between iron deficient and non-iron deficient subjects. Serum samples representing different concentrations of sTfR were tested. The three kits involved virtually the same laboratory procedures except for a predilution step for Ramco. Both the absolute amounts and the units (mg/L and nmol/L) differed among the kits, emphasizing the need for internationally accepted reference material and comparable units. The correlation coefficients were 0.974 (Ramco and R&D), 0.769 (R&D and Orion) and 0.759 (Ramco and Orion), indicating a lower comparability for Orion compared to the other two kits. The differences between the kits may be attributed to uncertainties in the reference intervals and to variations in kit format. This may have implications for studies of the usefulness of sTfR as a marker of iron deficiency.

Capillary density in patients with systemic sclerosis, as determined by microscopy counts and compared with computer-based analysis

OBJECTIVE

To develop a method enabling capillary density to be determined rapidly and accurately in patients with systemic sclerosis.

METHOD

Capillary density was determined in 11 controls and 22 patients: 5 with diffuse cutaneous systemic sclerosis (dSSc), 12 with limited cutaneous systemic sclerosis (lSSc), two with suspected systemic sclerosis (suspSSc), 2 with sclerodermatomyositis, and one with undifferentiated connective tissue disease. Using a microscope equipped with a graticule, nailfold capillaries were counted within a 3 mm length of the nailfold; these counts were made by 4 different observers. The results were compared with the corresponding values obtained by the computerbased analysis of photographs.

RESULTS

The median capillary density according to the direct counts was 8.0 loops/mm (6.7-10.0) in the controls, 6.0 loops/mm (range 4.8-8.8) in the dSSc subgroup, 5.6 loops/mm (4.2-6.5) in the lSSc subgroup, and 7.2 loops/mm (6.2-8.2) in the suspSSc subgroup. In the series as a whole, there was no significant difference between the median values for the left hands and those for the right hands, nor between the median value for all digit IVs and the median value for all four digits analysed (II, III, IV, and V). Interobserver variation was small between the 4 different observers. Direct microscopy counts were slightly higher than the corresponding values obtained by computer-based analysis.

CONCLUSION

Direct microscopy counting is a rapid, simple, and reliable means of determining capillary density for screening purposes.

Serum transferrin receptor: a specific marker of iron deficiency in pregnancy

BACKGROUND

Current markers of iron deficiency tend to be less reliable in pregnancy.

OBJECTIVE

Our aim was to study the usefulness of soluble serum transferrin receptor (sTfR) as a marker for iron deficiency during early and late gestation and to define iron status in 254 pregnant Swedish women.

DESIGN

We performed a cross-sectional and longitudinal evaluation of sTfR in comparison with concentrations of serum ferritin and hemoglobin in blood collected around gestational weeks 11 and 36.

RESULTS

The specificity of sTfR was 100%. The sensitivity in relation to both anemia and depleted iron stores was approximately 70%, but this figure is less reliable because of few samples. sTfR in early pregnancy was low: 11% of women had a value below the reference interval. sTfR increased significantly from early to late pregnancy even in the group of women with persisting iron stores. In late pregnancy, 14% of women developed tissue iron deficiency and 5% had iron deficiency according to a combination of all 3 markers.

CONCLUSIONS

sTfR seems to be a specific and sensitive marker of iron deficiency in pregnancy and may have advantages over serum ferritin and hemoglobin. The low sTfR concentration in early gestation seems to be caused by reduced erythropoiesis, whereas the increase from early to late pregnancy reflects increased erythropoiesis, and in case of iron deficiency, also tissue iron deficiency. Further studies are needed to verify whether decreased erythropoiesis reduces the possibility of detecting iron deficiency during early gestation by sTfR.

Mortality and causes of death in a Swedish series of systemic sclerosis patients

OBJECTIVES

To analyse survival rates and the causes of death in a systemic sclerosis (SSc) population, and to evaluate the occurrence of fatal malignant neoplasms and their possible association with oral cyclophosphamide (CYC) treatment.

METHODS

Survival was calculated for 249 SSc patients followed up for up to 13 years. Mean (SD) follow up was 5.8 (4.2) years. The 49 decreased patients were subdivided according to causes of death and its relation to SSc. Fatal malignancies in CYC treated patients were compared with those occurring in non-CYC treated patients.

RESULTS

The overall 5 and 10 year survival rates were 86% and 69% respectively. There was a 4.6-fold increased risk of death, as compared with the general population. Prognosis was worse in the diffuse cutaneous involvement (dSSc) and male subgroups than in the limited cutaneous involvement (1SSc) and female subgroups. Of the 49 deaths, 24 were attributable to pulmonary complications such as pulmonary fibrosis, pulmonary hypertension, pneumonia or pulmonary malignancy. Treatment with oral CYC did not increase the risk of dying of cancer.

CONCLUSIONS

Mortality is increased both in the SSc population as a whole and in its different subsets (dSSc and 1SSc). Prognosis is worst among male patients with dSSc. However, the 5 year survival rate was better than those reported from earlier studies. Most patients die of cardiopulmonary disease. Five of seven fatal lung cancers were adenocarcinomas, possibly caused by chronic inflammatory disease of the lung. In this study, CYC treatment was not associated with an increased incidence of fatal malignant neoplasms.

Cyclophosphamide therapy for scleroderma

Pulmonary manifestations are the most common cause of death in patients with scleroderma. Consequently, the importance of treatment of both interstital lung disease and pulmonary hypertension has become increasingly evident. Until a placebo-controlled study of any drug has shown its beneficial effect on pulmonary dysfunction, cyclophosphamide may be useful for the treatment of scleroderma lung disease.

Validation with biological markers for food intake of a dietary assessment method used by Swedish women with three different dietary preferences

OBJECTIVES

To validate a dietary assessment method, a 4-day food record together with a duplicate portion technique, with biological markers for food intake.

DESIGN

Four days of duplicate portions were collected in parallel with food recording. A 24-h urine sample and the faeces corresponding to the food intake (using a coloured marker) were collected. Completeness of urine and faeces collections was assessed using para-aminobenzoic acid (PABA) in urine and cadmium in faeces, respectively. Biomarkers of food intake (energy, protein, fibre, sodium, potassium, calcium) were measured in urine and faeces.

SETTING

Swedish west coast.

SUBJECTS

Non-smoking Swedish women, 20-50 years of age, consuming a mixed diet (n = 34), a mixed diet rich in shellfish (n = 17) or a vegetarian/high-fibre diet (n = 23).

RESULTS

The average ratio (food intake according to the dietary assessment methods/ biological marker) for protein, sodium, potassium and calcium was 0.86. This indicates an underestimation of the food intake by approximately 15%. The ratio of stated fibre intake to biological marker was 1.20 for the mixed diet and the vegetarian diet group, indicating an overestimation by approximately 20%.

CONCLUSIONS

The underestimation of the intake of protein, sodium, potassium and calcium by all three groups and the overestimation of the fibre intake by two groups indicate that underreporting is selective to certain nutrients and foods and to various groups of people. The two dependent dietary assessment methods were equally good in measuring protein intake, which indicates that the women recorded what they actually duplicated.

Tissue concentrations of gastrointestinal regulatory peptides in the duodenal mucosa in systemic sclerosis

OBJECTIVE

Esophageal hypomotility and abnormalities of intestinal function are important manifestations in systemic sclerosis (SSc), but their pathogenesis is not well understood. Since there is evidence that plasma concentrations of certain gastrointestinal regulatory peptides are increased in SSc, we were interested in examining the peptide concentrations and localization in biopsy specimens from the intestinal mucosa in SSc patients. We studied 12 patients with gastrointestinal disease.

METHODS

Levels of corticotrophin-releasing hormone (CRH), motilin, neuropeptide Y (NPY) and peptide YY (PYY) were determined by radioimmunoassay and high-performance liquid chromatography (HPLC), and the occurrence of motilin, PYY, somatostatin, and NPY were studied with immunohistochemistry.

RESULTS

Except for the concentrations of CRH, which were increased 2-fold, the tissue concentration of motilin, NPY and PYY were decreased by approximately 50% among patients with esophageal and intestinal dysfunction (group B) compared to patients with impaired esophageal motility alone (group A). In addition, HPLC-characterization of motilin, NPY, and PYY showed a different pattern of fragments among patients in groups A and B. In all patients duodenal motilin, PYY, and somatostatin were localized in the endocrine cells. The distribution and frequency of the cells did not differ among the patients. NPY was localized to neuronal elements; there was no overt difference among the patients with respect to the frequency of NPY-containing nerves.

CONCLUSION

This study shows that patients with widespread gastrointestinal disease have lower tissue concentrations of regulatory peptides compared to patients with less widespread disease.

Assessment of functional ability in patients with scleroderma: a proposed new disability assessment instrument

OBJECTIVE

To develop a simple assessment of functional ability in patients with scleroderma and to examine its reliability both as a patient self-administered instrument and when administered by a trained observer.

METHODS

An 11 item, 4 grade, functional assessment questionnaire was developed after extensive consultation with patients, physiotherapists (PT), and occupational therapists (OT) with the aim of including all functional areas of relevance. The instrument was self-administered by patients after an interval of 7 days. In the interval, the patients were assessed using the same instrument by direct observation from both a PT and an OT. Forty-seven patients with scleroderma, of varying severity, were recruited from 2 centers. Results were similar for both centers and data were pooled for analysis.

RESULTS

Agreement between the patients' first and 2nd assessment was good for all questions (estimated kappas 0.69 to 0.94) with no evidence of an order effect. Agreement was also good between therapists (estimated kappas 0.47 to 0.81). There was poor agreement between patients and therapists, with patients rating their disability substantially higher compared to the standardized therapist assessment.

CONCLUSION

This assessment schedule has high face and content validity and has excellent reliability both between trained therapists and within patients over a short time period. Its administration either as a self-report or by a therapist depends, in part, on the type of investigation undertaken.

Comparison of high frequency (20 MHz) ultrasound and palpation for the assessment of skin involvement in systemic sclerosis (scleroderma)

BACKGROUND AND OBJECTIVES

Systemic sclerosis (SSc) is a connective tissue disease characterized by microvascular changes and fibrosis of the skin and internal organs. Increased skin thickness proximal to the metacarpophalangeal joints is the single major diagnostic criterion. The aim of this study was to evaluate high frequency (20 MHz) ultrasound for the assessment of skin thickness in patients with SSc of different disease durations.

METHODS

Skin thickness was measured with high frequency (20 MHz) ultrasound equipment (Dermascan) in 41 patients with SSc (23 women and 18 men) and in 41 controls. Twenty-five patients had limited cutaneous systemic sclerosis (ISSc), 12 had diffuse cutaneous systemic sclerosis (dSSc) and 4 had suspected SSc.

RESULTS

Skin thickness of the forearm was inversely correlated to disease duration. Compared to controls, skin thickness was increased over the proximal phalanx of the right second finger and over the forearm in patients with a disease duration of 2 years or less. Assessments of skin thickness in 10 controls by 2 independent investigators showed an inter-observer variability of 1.0% for the proximal phalanx and 0.0016% for the forearm. Patients whose ultrasound showed increased skin thickness on the hand and forearm also had thickened skin by palpation.

CONCLUSION

High frequency (20MHz) ultrasound is a feasible method for measuring skin thickness in SSc, and may be useful for diagnosis, long-term follow-up, and assessment in therapeutic studies.

Altered dermatan sulfate proteoglycan synthesis in fibroblast cultures established from skin of patients with systemic sclerosis

OBJECTIVE

To study whether changes in the properties of skin from patients with systemic sclerosis (SSc) are the result of altered metabolism of dermatan sulfate proteoglycans.

METHODS

Fibroblast cultures were established from skin of healthy controls, and from affected and unaffected skin of patients with SSc. Synthesized proteoglycans were labeled with 3H glucosamine and 35S sulfate. The amount of mRNA of the different dermatan sulfate proteoglycans was determined by hybridization with the corresponding cDNA probes.

RESULTS

A 2-fold increase in secretion of total proteoglycans was found in cell cultures from affected and normal appearing skin from patients with SSc. The production of 2 different dermatan sulfate proteoglycans was increased. Aggrecan/versican increased 4-fold and decorin 2-fold in cultures of affected skin from patients with SSc. The mRNA for decorin increased 3-fold, while the mRNA level for versican increased only slightly. Similar but less marked changes were noted in cultures from normal appearing skin. In contrast, the biglycan mRNA level decreased and the product could only be found in very small amounts in SSc cultures.

CONCLUSION

This marked alteration of dermatan sulfate proteoglycan metabolism distinguishes not only affected skin but also normal appearing SSc skin from that of controls. The altered proteoglycan production may affect organization of matrix fibers and thereby the fibrotic process observed in patients with SSc.

Occurrence and distribution of peptidergic nerve fibers in skin biopsies from patients with systemic sclerosis

Systemic sclerosis is characterized by vascular dysfunction. Itch is sometimes present in early stages of the disease. This prompted us to study the innervation of the skin by immunocytochemistry. Antibodies to neuropeptide Y and vasoactive intestinal peptide were used for autonomic nerves. Sensory innervation was studied using antibodies to substance P and calcitonin gene-related peptide. Protein gene product 9.5 was used as a general neuronal marker. Skin biopsies from affected (lower arm) and non-affected (upper back) sites on 10 patients with systemic sclerosis and from corresponding sites on 10 sex- and age-matched healthy controls were studied. Regional variations were found in the occurrence of peptidergic nerve fibers. In the patients the density of nerve fibers (measured semiquantitatively) stained by the panneuronal marker was lower in affected than in unaffected skin (p < 0.05). There were no significant differences in peptidergic innervation between patients and controls. However, there was a tendency to higher density of neuropeptide Y-positive nerve fibers in the forearm skin in 6 to 10 patients, as compared to only 1 of 10 healthy controls.

Bioavailability of cadmium from shellfish and mixed diet in women

Dietary intake and uptake of cadmium (Cd) were studied in nonsmoking women, 20-50 years of age, consuming a mixed diet low in shellfish (N = 34) or with shellfish once a week or more (N = 17). Duplicate diets were collected during 4 consecutive days for the determination of Cd content. The women kept detailed dietary records, and the intake of energy and various nutrients was calculated. The shellfish diets (median 22.3 micrograms Cd/day) contained twice as much Cd as the mixed diets (median 10.5 micrograms Cd/day; p < 0.0001). Cadmium in feces corresponded to 100 and 99% of that in duplicates of shellfish diets and mixed diets, respectively, indicating a low average absorption of the dietary Cd. In spite of the differences in the daily intake of Cd, there was no statistically significant difference in the concentrations of Cd in blood (B-Cd, shellfish group 0.25 micrograms/liter, mixed diet group 0.23 micrograms/liter) or urine (U-Cd, 0.10 micrograms Cd/liter in both groups). This indicates a lower absorption of Cd in the shellfish group than in the mixed diet group or a difference in the kinetics. A higher gastrointestinal absorption of Cd in the mixed diet group could partly be explained by lower body iron stores as measured by the concentrations of serum ferritin (S-fer, median 18 micrograms/liter, compared to 31 micrograms/liter in the shellfish group). In the mixed diet group, S-fer was negatively correlated with B-Cd and the main determining for B-Cd besides U-Cd in the multiple regression analysis, indicating an increased absorption of Cd at low body iron stores. When women with S-fer exceeding 20 micrograms/liter were compared, the higher dietary intake of Cd in the shellfish group compared to the mixed diet group (24 versus 10 micrograms/day) resulted in higher B-Cd (0.26 versus 0.16 micrograms/liter), although not in proportion to the difference in Cd intake. Thus, there seems to be differences in the bioavailability and/or kinetics of dietary Cd related to the type of diet. This is, to our knowledge, the first study where the influence of various types of diets and nutritional factors on the intake and uptake of cadmium in human subjects has been studied.

Computer based quantitative analysis of capillary abnormalities in systemic sclerosis and its relation to plasma concentration of von Willebrand factor

OBJECTIVES

To evaluate an objective and quantitative method for assessment of capillary abnormalities in systemic sclerosis (SSc).

METHODS

Nailfold capillaries were investigated by capillary microscopy and photographed in 17 consecutive SSc patients (five with diffuse cutaneous systemic sclerosis (dSSc) and 12 with limited cutaneous systemic sclerosis (lSSc)) and in 17 healthy controls. Investigators having no access to clinical data made drawings from magnified projections of coded photographs and analysed them using a computer program. Capillary density (capillary loops/mm in the distal row) and median capillary loop area were calculated. Presence of functional or organic arterial changes was evaluated by measurement of finger pressure with finger cooling. Plasma concentration of von Willebrand factor (VWF) was analysed using an enzyme linked immunosorbent assay (ELISA).

RESULTS

In 16 of 17 SSc patients and 13 of 17 controls the technical quality of the photographs was sufficient for computer analysis. Capillary density was decreased in dSSc (median 6.9 loops/mm) and in lSSc (median 3.8 loops/mm) compared with healthy controls (8.9 loops/mm) and median capillary loop area was increased in dSSc (7.3 x 10(-3) mm2) and in lSSc (8.5 x 10(-3) mm2) compared with healthy controls (5.0 x 10(-3) mm2). An inverse relation was found between capillary density and median capillary loop area in SSc patients. Plasma VWF was increased in patients (median 401 IE/l in dSSc and 409 IE/l in lSSc) compared with controls matched for age and sex (median 276 IE/l). Computer based analysis showed capillary density below the control range and median capillary loop area above the control range in 14 of 16 SSc patients. Measurement of finger pressure with finger cooling showed organic vascular changes in nine of 13 SSc patients.

CONCLUSION

Computer based quantitative analysis has low interobserver variability and is a quantitative and sensitive method of assessing capillary abnormalities in SSc.

Esophageal scintigraphy of systemic sclerosis

Esophageal involvement is common in systemic sclerosis, and esophageal scintigraphy can be used to detect and follow esophageal dysfunction. This study assesses the value of visual and quantitative analysis of esophageal scintigraphy performed as a multiple swallow test in normals and patients with systemic sclerosis.

METHODS

Forty patients with systemic sclerosis and 40 sex- and age-matched healthy subjects (controls) were studied. A multiple swallow technique was used and both quantitative and qualitative analyses were performed. Visual analysis of condensed images was performed independently by two physicians. Each swallow was assigned a score on a scale from 1 to 4. In the quantitative analysis, time-activity curves based on the mean condensed images were used to calculate the following 3 parameters: residual activity 12 or 25 sec after the beginning of the swallow, measured with or without baseline correction, respectively, and time from onset of swallow to 50% of peak activity.

RESULTS

Both visual and quantitative analysis showed a highly significant (p < 0.001) difference between the patient group and the control group. Visual analysis was best reflected by the residual activity 25 sec after the beginning of the swallow without correction for background. Receiver operating characteristic curves were used to study the ability to separate the two groups using visual or quantitative analysis. A high rate of positive tests in the patient group was achieved only at the cost of a relatively high rate of positive tests in the control group.

CONCLUSION

Our results indicate high variability in esophageal motility in controls. This variability impairs the possibilities of developing a screening test to identify asymptomatic patients early in the disease course.