Simulating rewetting events in intermittent rivers and ephemeral streams: A global analysis of leached nutrients and organic matter

Climate change and human pressures are changing the global distribution and the extent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico-chemical changes (preconditioning), and periods of flow resumption, when these substrates are rewetted and release pulses of dissolved nutrients and organic matter (OM). However, there are no estimates of the amounts and quality of leached substances, nor is there information on the underlying environmental constraints operating at the global scale. We experimentally simulated, under standard laboratory conditions, rewetting of leaves, riverbed sediments, and epilithic biofilms collected during the dry phase across 205 IRES from five major climate zones. We determined the amounts and qualitative characteristics of the leached nutrients and OM, and estimated their areal fluxes from riverbeds. In addition, we evaluated the variance in leachate characteristics in relation to selected environmental variables and substrate characteristics. We found that sediments, due to their large quantities within riverbeds, contribute most to the overall flux of dissolved substances during rewetting events (56%-98%), and that flux rates distinctly differ among climate zones. Dissolved organic carbon, phenolics, and nitrate contributed most to the areal fluxes. The largest amounts of leached substances were found in the continental climate zone, coinciding with the lowest potential bioavailability of the leached OM. The opposite pattern was found in the arid zone. Environmental variables expected to be modified under climate change (i.e. potential evapotranspiration, aridity, dry period duration, land use) were correlated with the amount of leached substances, with the strongest relationship found for sediments. These results show that the role of IRES should be accounted for in global biogeochemical cycles, especially because prevalence of IRES will increase due to increasing severity of drying events.

Disentangling natural and anthropogenic impacts on groundwater by hydrogeochemical, isotopic and microbiological data: Hints from a municipal solid waste landfill

Within human-impacted areas, high levels of inorganic compounds in groundwater are broadly and preventively attributed to local anthropogenic pollution, thoroughly disregarding geogenic natural background levels. Particularly in landfills, a proper evaluation of the significant adverse environmental effects should be completed through a detailed groundwater characterization, and appropriate reference values established prior to landfill onset. However, the monitoring network may lack a full hydrogeological representativeness of the site and of the background conditions of groundwater. This study aimed at disentangling natural and anthropogenic impacts through a synoptic analysis of hydrogeochemical, isotopic and microbiological characteristics of groundwaters from a municipal solid waste landfill area in Central Italy. Samples were collected during four seasonal monitoring surveys from the mostly anoxic aquifer underlying the target area. Field parameters, inorganic and organic compounds, environmental isotopes, faecal contamination, and microbial community characteristics were determined, along with a detailed hydrogeological conceptual model. Key inorganic contaminants (As, Fe and Mn) exceeded the local threshold values in most of the sampling points, while organic contamination was generally very low. Stable isotopes suggested that groundwater originated mainly from local rainfall, except at one monitoring points where tritium levels might indicate moderate impact. Microbiological data and the microbial community characterization, assessed by flow cytometry and BIOLOG assays, provided further supportive information, also highlighting fundamental effects of groundwater quality alterations. Overall, an integrated multi-parametric approach proved suitable to distinguish geogenic and anthropogenic impacts, thus improving strategies and schemes for protection and management of groundwaters in landfills and waste related industrial areas.

Distribution patterns of organic pollutants and microbial processes in marine sediments across a gradient of anthropogenic impact

Marine sediments are part of the hydrological cycle and the ultimate storage compartment of land-derived organic matter, including pollutants. Since relevant microbially-driven processes occurring at benthic level may affect the quality of the overall aquatic system, the necessity for incorporating information about microbial communities functioning for ecosystem modelling is arising. The aim of this field study was to explore the links occurring between sediment contamination patterns by three selected class of organic pollutants (Polycyclic Aromatic Hydrocarbons, PAHs, Nonylphenols, NPs, Bisphenol A, BPA) and major microbial properties (Prokaryotic Biomass, PB; total living biomass, C-ATP; Prokaryotic C Production rate, PCP; Community Respiration rate, CR) across a gradient of anthropogenic pollution. Sediments were sampled from 34 sites selected along 700 km of the western coastline of the Adriatic Sea. Organic contamination was moderate (PAHs <830 ng g^-1; NPs <350  ng g^-1; BPA <38  ng g^-1) and decreased southward. The amount of PAHs-associated carbon (C-PAHs) increased significantly with sediment organic carbon (OC), along with microbial functional rates. The negative relation between PCP/CR ratio and OC indicated the shift toward oxidative processes in response to organic pollution and potential toxicity, estimated as Toxic Equivalents (TEQs). Our outcomes showed that sediment organic contamination and benthic microbial processes can be intimately linked, with potential repercussions on CO₂ emission rates and C-cycling within the detritus-based trophic web.

Science and Management of Intermittent Rivers and Ephemeral Streams (SMIRES)

More than half of the global river network is composed of intermittent rivers and ephemeral streams (IRES), which are expanding in response to climate change and increasing water demands. After years of obscurity, the science of IRES has bloomed recently and it is being recognised that IRES support a unique and high biodiversity, provide essential ecosystem services and are functionally part of river networks and groundwater systems. However, they still lack protective and adequate management, thereby jeopardizing water resources at the global scale. This Action brings together hydrologists, biogeochemists, ecologists, modellers, environmental economists, social researchers and stakeholders from 14 different countries to develop a research network for synthesising the fragmented, recent knowledge on IRES, improving our understanding of IRES and translating this into a science-based, sustainable management of river networks. Deliverables will be provided through i) research workshops synthesising and addressing key challenges in IRES science, supporting research exchange and educating young researchers, and ii) researcher-stakeholder workshops translating improved knowledge into tangible tools and guidelines for protecting IRES and raising awareness of their importance and value in societal and decision-maker spheres. This Action is organized within six Working Groups to address: (i) the occurrence, distribution and hydrological trends of IRES; (ii) the effects of flow alterations on IRES functions and services; (iii) the interaction of aquatic and terrestrial biogeochemical processes at catchment scale; (iv) the biomonitoring of the ecological status of IRES; (v) synergies in IRES research at the European scale, data assemblage and sharing; (vi) IRES management and advocacy training.

Microbial responses to polycyclic aromatic hydrocarbon contamination in temporary river sediments: Experimental insights

Temporary rivers are characterized by dry-wet phases and represent an important water resource in semi-arid regions worldwide. The fate and effect of contaminants have not been firmly established in temporary rivers such as in other aquatic environments. In this study, we assessed the effects of sediment amendment with Polycyclic Aromatic Hydrocarbons (PAHs) on benthic microbial communities. Experimental microcosms containing natural (Control) and amended sediments (2 and 20 mg PAHs kg(-1) were incubated for 28 days. The PAH concentrations in sediments were monitored weekly together with microbial community structural (biomass and phylogenetic composition by TGGE and CARD-FISH) and functional parameters (ATP concentration, community respiration rate, bacterial carbon production rate, extracellular enzyme activities). The concentration of the PAH isomers did not change significantly with the exception of phenanthrene. No changes were observed in the TGGE profiles, whereas the occurrence of Alpha- and Beta-Proteobacteria was significantly affected by the treatments. In the amended sediments, the rates of carbon production were stimulated together with aminopeptidase enzyme activity. The community respiration rates showed values significantly lower than the Control after 1 day from the amendment then recovering the Control values during the incubation. A negative trend between the respiration rates and ATP concentration was observed only in the amended sediments. This result indicates a potential toxic effect on the oxidative phosphorylation processes. The impoverishment of the energetic resources that follows the PAH impact may act as a domino on the flux of energy from prokaryotes to the upper level of the trophic chain, with the potential to alter the temporary river functioning.

Groundwater geochemistry and microbial community structure in the aquifer transition from volcanic to alluvial areas

Groundwaters may act as sinks or sources of organic and inorganic solutes, depending on the relative magnitude of biochemical mobilizing processes and groundwater-surface water exchanges. The objective of this study was to link the lithological and hydrogeological gradients to the aquatic microbial community structure in the transition from aquifer recharge (volcanic formations) to discharge areas (alluvial deposits). A field-scale analysis was performed along a water table aquifer in which volcanic products decreased in thickness and areal extension, while alluvial deposits became increasingly important. We measured the main groundwater physical parameters and the concentrations of major and trace elements. In addition, the microbial community structure was assessed by estimating the occurrence of total coliforms and Escherichia coli, the prokaryotic abundance, the cytometric and phylogenetic community composition. The overall biogeochemical asset differed along the aquifer flow path. The concentration of total and live prokaryotic cells significantly increased in alluvial waters, together with the percentages of Beta- and Delta-Proteobacteria. The microbial propagation over a theoretical groundwater travel time allowed for the identification of microbial groups shifting significantly in the transition between the two different hydrogeochemical facies. The microbial community structure was intimately associated with geochemical changes, thus it should be further considered in view of a better understanding of groundwater ecology and sustainable management strategies.

Organic priority substances and microbial processes in river sediments subject to contrasting hydrological conditions

Flood and drought events of higher intensity and frequency are expected to increase in arid and semi-arid regions, in which temporary rivers represent both a water resource and an aquatic ecosystem to be preserved. In this study, we explored the variation of two classes of hazardous substances (Polycyclic Aromatic Hydrocarbons and Nonylphenols) and the functioning of the microbial community in river sediments subject to hydrological fluctuations (Candelaro river basin, Italy). Overall, the concentration of pollutants (∑PAHs range 8-275ngg(-1); ∑NPs range 299-4858ngg(-1)) suggests a moderate degree of contamination. The conditions in which the sediments were tested, flow (high/low) and no flow (wet/dry/arid), were associated to significant differences in the chemical and microbial properties. The total organic carbon contribution decreased together with the stream flow reduction, while the contribution of C-PAHs and C-NPs tended to increase. NPs were relatively more concentrated in sediments under high flow, while the more hydrophobic PAHs accumulated under low and no flow conditions. Passing from high to no flow conditions, a gradual reduction of microbial processes was observed, to reach the lowest specific bacterial carbon production rates (0.06fmolCh(-1)cell(-1)), extracellular enzyme activities, and the highest doubling time (40h) in arid sediments. In conclusion, different scenarios for the mobilization of pollutants and microbial processes can be identified under contrasting hydrological conditions: (i) the mobilization of pollutants under high flow and a relatively higher probability for biodegradation; (ii) the accumulation of pollutants during low flow and lower probability for biodegradation; (iii) the drastic reduction of pollutant concentrations under dry and arid conditions, probably independently from the microbial activity (abiotic processes). Our findings let us infer that a multiple approach has to be considered for an appropriate water resource exploitation and a more realistic prevision of the impact of pollutants in temporary waters.

Colonization of overlaying water by bacteria from dry river sediments

We studied the diversity, community composition and activity of the primary microbial colonizers of the water above freshly re-wetted sediments from a temporary river. Dried sediments, collected from Mulargia River (Sardinia, Italy), were covered with sterile freshwater in triplicate microcosms, and changes of the planktonic microbial assemblage were monitored over a 48 h period. During the first 9 h bacterial abundance was low (1.5 x 10(4) cells ml(-1)); it increased to 3.4 x 10(6) cells ml(-1) after 28 h and did not change thereafter. Approximately 20% of bacteria exhibited DNA de novo synthesis already after 9 h of incubation. Changes of the ratios of (3)H-leucine to (3)H-thymidine incorporation rates indicated a shift of growth patterns during the experiment. Extracellular enzyme activity showed a maximum at 48 h with aminopeptidase activity (430.8 +/- 22.6 nmol MCA l(-1) h(-1)) significantly higher than alkaline phosphatase (98.6 +/- 4.3 nmol MUF l(-1) h(-1)). The primary microbial colonizers of the overlaying water - as determined by 16S rRNA gene sequence analysis - were related to at least six different phylogenetic lineages of Bacilli and to Alphaproteobacteria (Brevundimonas spp. and Caulobacter spp.). Large bacterial cells affiliated to one clade of Bacillus sp. were rare in the dried sediments, but constituted the majority of the planktonic microbial assemblage and of cells with detectable DNA-synthesis until 28 h after re-wetting. Their community contribution decreased in parallel with a rise of flagellated and ciliated protists. Estimates based on cell production rates suggested that the rapidly enriched Bacillus sp. suffered disproportionally high loss rates from selective predation, thus favouring the establishment of a more heterogenic assemblage of microbes (consisting of Proteobacteria, Actinobacteria and Cytophaga-Flavobacteria). Our results suggest that the primary microbial colonizers of the water above dried sediments are passively released into the plankton and that their high growth potential is counteracted by the activity of bacterivorous protists.

Responses of benthic bacteria to experimental drying in sediments from Mediterranean temporary rivers

In the semiarid Mediterranean regions, water scarcity represents a common physiological stress for microbial communities residing in river sediments. However, the effect of drying has not yet adequately been evaluated when analyzing riverine microbiological processes. The bacterial community structure (abundance, biomass, composition) and functioning (carbon production, live cell percentage) were assessed during experimental desiccation in microcosms with sediments from different Mediterranean temporary rivers (Tagliamento, Krathis, Mulargia, Pardiela). Our results showed that the overall responses to drying of the bacterial community were independent from sediment origin and strictly related to water content. During desiccation, a prompt decline (up to 100%) of the initial bacterial carbon production was followed by a slower decrease in abundance and biomass, with an overall reduction of 74% and 78%, respectively. By the end of the experiment, live cells were still abundant but depressed in their main metabolic functions, thus resulting in a drastic increase in the community turnover time. Only 14% of the initial live cell biomass was available in dry sediments to immediately start the reactivation of the aquatic microbial food web after the arrival of new water. Community composition analysis showed a relative increase in alpha- and beta-Proteobacteria, when passing from wet to dry conditions. Our results suggest that the occurrence of drought events could affect carbon cycling through the freshwater microbial compartment, by temporarily limiting microbial mineralization and altering bacterial community structure.

Extracellular enzyme activity and dynamics of bacterial community in mucilaginous aggregates of the northern Adriatic Sea

Bacterial degradation of mucilaginous aggregates (creamy layers, stringers and macroflocs) collected during two summer events (2001-2002) was tested. The objective was to describe the temporal trend of the bacterial activity, abundance and composition in the aggregated and dissolved organic matter under different trophic conditions. In the native aggregates proteins and organic phosphorous were actively hydrolyzed as aminopeptidase and alkaline phosphatase activities represented up to 87% and 25% of total activity, respectively; polysaccharides were less hydrolyzed and the highest activities were observed for beta-glucosidase (5% of the total). This hydrolysation pattern tends to a progressive accumulation of long persistent polysaccharides. During short term incubations nutrient addition (P, N and Glucose) differently stimulated bacterial growth in the seawater: P played the main role in stimulating bacterial production from 3 to 6 folds higher than in the control, whereas a secondary C-limitation was observed only for bacteria growing on seawater from macroflocs. This scarce dissolved organic carbon (DOC) bioavailability was confirmed by the lower DOC removal (13% macroflocs, 36% stringers). The total amount of carbon incorporated by bacteria living on aggregates was similar (0.58 mg C L(-1)) both in the control and under P enrichments showing a more balanced condition with respect to the seawater. Hence the well-known P limitation in the Northern Adriatic Sea affects only dissolved organic carbon uptake without influencing the uptake of aggregated organic matter. Organic matter limitation was observed only on stringers--total C incorporated raised to 0.96 mg C L(-1) after PNG addition. Macroflocs release of refractory compounds leads to DOC accumulation (73 microM DOC) contributing to inflate the pool of refractory DOC in the surrounding waters. Several evidences, including different monosaccharide composition of stringers and macroflocs (glucose 15% and 56% on stringers and macroflocs, respectively), bring to the conclusion that stringers are in an older stage in comparison with macroflocs. Community composition described by fluorescence in situ hybridization did not show significant differences between free-living and attached bacteria but it was modified by the different enrichment conditions: Cytophaga-Flavobacteria increased after inorganic nutrients enrichments while organics advantaged gamma-Proteobacteria.

Effects of small-scale turbulence on bacteria: a matter of size

We examined the influence of small-scale turbulence and its associated shear on bacterioplankton abundance and cell size. We incubated natural microbial assemblages and bacteria-only fractions and subjected them to treatments with turbulence and additions of mineral nutrients and/or organic carbon. Bacterial abundance was not affected directly by turbulence in bacteria-only incubations. In natural microbial assemblage incubations, bacterial concentrations were higher under turbulence than in still-water controls when nutrients were added. In general, in the turbulence treatments bacteria increased significantly in size, mainly due to elongation of cells. The addition of inorganic nutrients had a negative effect on bacterial size, but a significantly positive effect on abundance independently of other factors such as turbulence and the presence of predators. Flagellate grazing did not trigger an increase in bacterial size as a grazing resistance response in unmixed containers. With the addition of organic carbon, bacteria elongated and partly settled to the bottom of the containers, in both the turbulent and still treatment, but bacterial abundance did not further increase. Furthermore, bacteria aggregated in the turbulence treatments after the second day of incubation even in the absence of other components of the microbial community. We found that turbulence and the associated shear increase bacterial size and change bacterial morphology, at least under certain nutrient conditions. This might be due to a physiological response (enhanced growth rate and/or unbalanced growth) or due to the selection of opportunistic strains when organic carbon is in excess compared to mineral nutrients. We suggest that shear associated with turbulent flow enhances the DOM flux to bacteria directly as well as indirectly through enhanced grazing activity and photosynthetic release. The formation of bacterial aggregates and filaments under turbulence might give selective advantage to bacteria in terms of nutrient uptake and grazing resistance.

[Immunohistochemical analysis of the expression of main adhesion molecules and tumor necrosis factors in the synovial membrane of psoriatic arthritis]

OBJECTIVE

To define the expression and pattern of the synovial distribution of adhesion molecules such as E-selectin, ICAM-1 and VCAM-1 and of TNFalpha and TNFbeta cytokines in psoriatic arthritis (PsA), according to the synovitis duration.

METHODS

Cryostatic sections of the synovial membrane tissue samples were stained for the different antibodies using a standard three-stage-immunoperoxidase-labeling technique.

RESULTS

E-selectin grade of staining was higher in those patients with a shorter disease duration compared to longstanding synovitic specimens, as well as ICAM-1 expression. On the contrary a higher VCAM-1 positivity was mainly found in longstanding PsA patients. Anti-TNFalpha positivity was found almost in all the specimens with no difference among the two groups, while the intensity of anti-TNFbeta positivity was globally higher in longstanding cases.

CONCLUSIONS

Different adhesion molecules may separately participate to the synovitic process in the different phases of PsA, leading to the hypothesis of their different involvement during the disease evolution. Moreover the upregulation of TNFalpha and TNFbeta gives evidence to their local proinflammatory effect within the synovium and to their role in perpetuating the PsA synovitis.

Class specific rheumatoid factors and antiphospholipid syndrome in systemic lupus erythematosus

The relationship of rheumatoid factors (RF) with antiphospholipid syndrome (aPLS) and anticardiolipin antibodies (aCL) has rarely been investigated in systemic lupus erythematosus (SLE). We found IgM-RF, IgG-RF, IgA-RF, IgM-aCL, IgG-aCL, IgA-aCL, respectively, in 35.4%, 35.4%, 33.8%, 23.1%, 23.1%, 20.0% of 65 SLE patients. Class specific RFs were negatively associated (P<0.05) with IgG-aCL. The frequency of definite or probable aPLS according to Alarcon-Segovia classification criteria was significantly (P<0.05) different (8.7% vs 30.9%) in patients with or without IgG-RF. Among the other clinical features of SLE, we found that patients with IgG-RF, compared to patients lacking this autoantibody, showed a lower frequency (P<0.05) of serositis (21.7% vs 52.4%) and hematologic (52. 2% vs 80.9%) disorders. The levels of IgG-RF and IgM-RF negatively correlated with the number of ARA criteria (P<0.05) but not with the indices of diseases activity or damage. Our study shows that in SLE the presence of RFs are not markers of severity of the disease, but the negative association between IgG-RF and IgG-aCL suggests a distinct role of these autoantibodies in the pathology of SLE, whereas the presence of IgG isotype may identify a subset of SLE patients having a lower risk to develop some clinical manifestations such as aPLS.

Changes of glycosylation of serum proteins in Sjögren's syndrome: correlation with interleukin-6 and soluble interleukin-2 receptor

A strong increase of the affinity for concanavalin A (Con A) of serum alpha 2-macroglobulin, a non-acute-phase protein, was observed by lectin blotting in patients with Sjögren's syndrome (SS). On the contrary, the total Con A reactivity of serum proteins, measured by enzyme-linked lectin assay, was not augmented in SS, compared with normal donors, probably because positive changes of certain proteins were balanced by negative changes of others, as suggested by lectin blotting analysis. However, a significant increase of total Con A reactivity occurred in subjects with increased serum concentrations of soluble interleukin (IL)-2 receptor, compared with patients with normal concentrations of this marker of disease activity. On the other hand, the same parameter did not appear to be different in patients with normal or increased serum concentrations of IL-6, indicating that this cytokine was not probably responsible for the changes of glycosylation described here.

Changes of glycosylation of serum proteins in psoriatic arthritis, studied by enzyme-linked lectin assay (ELLA), using concanavalin A

Changes of glycosylation of serum proteins of patients with psoriatic arthritis were detected by lectin blotting and a new enzyme-linked lectin assay (ELLA) using concanavalin A (Con A). A good linear correlation was found between the total Con A-reactivity of serum and the serum levels of C-reactive protein and interleukin-6, which is known to regulate the glycosylation pattern of proteins upon inflammation. A good linear correlation was also observed between the immunoreactivity of alpha 1-antitrypsin, measured by ELISA, using a monoclonal antibody sensitive to glycosylation changes, and the erythrocyte sedimentation rate and the serum concentrations of soluble interleukin-2 receptor, an index of lymphocyte activation which correlated with some inflammatory parameters of disease activity. These protein changes, which are described here for the first time, deserve to be studied in further detail in view of their possible clinical applications.

Life-table analysis of cyclosporin A treatment in psoriatic arthritis: comparison with other disease-modifying antirheumatic drugs

OBJECTIVES

The aim of this study was to determine the cumulative probability of taking CsA in comparison to other DMARDs, as well as the reason for discontinuation of each DMARD, in a large cohort of PsA patients.

METHODS

We prospectively studied 172 consecutive patients with a diagnosis of PsA who had been admitted to our rheumatological unit since 1984. We collected information about treatment with DMARDs including: number, dose, duration and causes of withdrawal, including side effects or inefficacy. Cumulative survival analysis was performed by the Kaplan-Meier test and the differences between these survival curves were determined by the Mantel-Hanszel test.

RESULTS

The probability curve of continuing to take CsA was significantly lower than that of MTX (p < 0.046). The rate of adverse effects responsible for stopping DMARD therapy was higher in the CsA group, especially with respect to the antimalarial group (p < 0.014). The most common cause of CsA withdrawal was hypertension. The rate of withdrawal due to inefficacy in the CsA group was not significantly different from those observed in the other groups. Nevertheless, the total frequency of discontinuation due to toxicity and inefficacy in the MTX group was significantly lower compared to the gold salts (p < 0.05) and CsA groups (p < 0.01).

CONCLUSION

Life-table analysis suggests that PsA patients taking CsA are less likely than patients on MTX to continue long term treatment. Therefore CsA, which seems to be less safe than the antimalarials, could be considered a useful drug in the treatment of PsA, but does seem to represent the drug of first choice, particularly when compared to MTX.

Effects of cyclosporin on joint damage in rheumatoid arthritis. The Italian Rheumatologists Study Group on Rheumatoid Arthritis

According to the most recent literature, few antirheumatic drugs can claim disease-controlling properties over the anatomical joint damage in rheumatoid arthritis (RA). A small number of studies have favored one or another of the available agents, in particular parenteral gold salts, sulphasalazine and methotrexate, but the evidence regarding their efficacy is not convincing when analysed using methodological criteria known to be important in evaluating radiologic evidence of joint damage. The radiologic results in long-standing RA patients have shown that CsA may be of benefit in reducing disease progression. Data from the second year of a clinical trial designed to compare the disease-controlling, anti-rheumatic properties of CsA with those of conventional disease-modifying anti-rheumatic drugs (DMARDs) in early RA support the hypothesis that CsA may be useful in delaying the appearance of new joint erosion.

Relationship of soluble interleukin-2-receptor and interleukin-6 with class-specific rheumatoid factors during low-dose methotrexate treatment in rheumatoid arthritis

We studied the effect of a 6-month treatment with low-dose MTX in 22 RA patients, with the purpose of investigating the relationship of sIL-2R and IL-6 serum changes with those of class specific RFs. The patients with RA had higher serum levels of sIL-2R (p < 0.0001), and IL-6 (p < 0.0005) than healthy volunteers. We found that the levels of IgM-RF (p < 0.0004), IgA-RF (p < 0.002), IgG-RF (p < 0.025), sIL-2R (p < 0.017) and IL-6 (p < 0.044) as well as the main clinical and laboratory variables, were significantly reduced in RA patients treated with low dose MTX for six months. The changes from baseline of IgM-RF correlated with those of IL-6 (p < 0.023), suggesting that MTX may affect IL-6 and IgM-RF production in part by a common mechanism. In conclusion our results show that there is a relationship between IL-6 and IgM-RF changes from baseline during MTX therapy, but the hypothesis of a link between the effects of this drug on cytokine network and RF production needs further investigation.

Interleukin-6 and soluble interleukin-2-receptor in psoriatic arthritis: correlations with clinical and laboratory parameters

OBJECTIVE

In this study we evaluated the relationships of IL-6 and sIL-2R levels with the main clinical and laboratory parameters in PsA patients with peripheral polyarthritis.

METHODS

Serum levels of IL-6 and sIL-2R were measured by an enzyme immunoassay kit in patients with peripheral (< 4 joints) PsA (n = 47), with RA (n = 41), or with psoriasis (N = 15) and in healthy volunteers (n = 15)

RESULTS

The patients with PsA had higher serum levels of IL-6 and sIL-2R than healthy volunteers and psoriatic patients, while they showed lower levels of IL-6 and sIL-2R than RA patients. We found abnormal values for IL-6 and sIL-2R in 63.8% and 57.4% of PsA patients, respectively. IL-6 levels correlated with the number of painful and swollen joints, RAI, physician's assessment, CRP and ESR, while sIL-2R levels correlated only with the number of swollen joints, the physician's assessment and ESR. IL-6 and sIL-2R correlated with each other.

CONCLUSION

Our study shows that IL-6 and sIL-2R may play a role in the pathogenetic mechanism of psoriatic arthritis.

Comparison of ultrasound transmission velocity with computed metacarpal radiogrammetry and dual-photon absorptiometry

The aim of our study was to evaluate the validity of a quantitative US technique for measuring the bone density of the proximal phalanges of the nondominant hand compared with computed metacarpal radiogrammetry and dual-photon absorptiometry (DPA) of the lumbar spine. Mean US bone velocity (UBV) correlated with mean metacarpal cortical index (MCI), with mean metacarpal bone density (MBD) and with bone mineral density (BMD) of the lumbar spine, whereas it was correlated negatively with age and menopause duration. The average UBV was significantly higher in premenopausal women than in postmenopausal women, and higher in normal lumbar DPA patients than in reduced lumbar DPA patients. We conclude that the US evaluation of the nondominant hand proximal phalanges may be a new alternative way for measuring bone mass in screening of osteoporosis.

Interleukin-6 and soluble interleukin-2 receptor in juvenile chronic arthritis: correlations with clinical and laboratory parameters

We sought to determine whether levels of interleukin-6 and soluble interleukin-2 receptor were correlated with clinical parameters including functional capacity indices such as Steinbrocker's class and the Juvenile Arthritis Functional Assessment Report (JAFAR) score, with tests for inflammation, and/or with immunological parameters in 24 patients with active polyarticular or pauciarticular juvenile chronic arthritis. Levels of interleukin-6 and soluble interleukin-2 receptor were significantly higher in juvenile chronic arthritis patients than in healthy controls (p < 0.005 and p < 0.00005, respectively). Interleukin-6 levels were correlated with the following parameters: number of painful joints (p < 0.025); Ritchie's index (p < 0.025); visual analog scale pain score (p < 0.025); Steinbrocker's class (p < 0.025); JAFAR score determined by patients (p < 0.05); JAFAR score determined by parents (p < 0.05); erythrocyte sedimentation rate (p < 0.0002); and serum levels of C-reactive protein (p < 0.0003), hemoglobin (p < 0.05), albumin (p < 0.025), and alpha 2-globulins (p < 0.025). Levels of soluble interleukin-2 receptor did not correlate with any of the parameters studied. Levels of interleukin-6 and soluble interleukin-2 receptor were not correlated with each other. Abnormal levels of interleukin-6 or soluble interleukin-2 receptor were not significantly associated with the presence of antinuclear antibodies, IgM-rheumatoid factor, IgA rheumatoid factor or anticardiolipin antibodies. Our findings suggest that interleukin-6 is a useful parameter for assessing juvenile chronic arthritis and that the potential clinical value of elevated levels of soluble interleukin-2 receptor in this disease needs to be further evaluated in longitudinal studies.

Comparison of cyclosporin A and methotrexate in the treatment of psoriatic arthritis: a one-year prospective study

OBJECTIVE

To compare the effectiveness and toxicity of cyclosporin A (CsA) vs low-dose methotrexate (MTX) over a period of one year in the treatment of psoriatic arthritis (PsA) with peripheral involvement.

METHODS

Thirty-five patients with PsA were enrolled in a prospective, controlled, randomized trial. CsA was initially given in doses of 3 mg/kg/day to a maximum permitted dose of 5 mg/kg/day; MTX was given in oral doses of 2.5 mg every 12 hours for 3 consecutive doses each week up to a maximum dose of 15 mg/weekly. Clinical and laboratory evaluations were performed at entry and monthly thereafter.

RESULTS

After 6 and 12 months the number of painful joints, the number of swollen joints, the Ritchie index, the duration of morning stiffness, grip strength, CRP, the patient's and the physician's assessment of PsA activity, as well as the PASI, were significantly improved in both treatment groups. ESR values were significantly reduced only in the MTX group (p < 0.01), which also showed a significantly increase of liver enzymes. The changes in the main clinical and laboratory parameters during the course of CsA or MTX treatment were not significantly different except for the AST and ALT levels (p < 0.05). After one year of therapy CsA and MTX were withdrawn in 41.2% and 27.8% of the patients respectively, but these differences were not statistically significant.

CONCLUSION

Our one-year prospective trial shows that low-dose CsA and MTX are both effective in the treatment of PsA, but the differences in the tolerability of these drugs must be considered at the start of therapy.

Long-term follow-up of low-dose methotrexate therapy in one case of idiopathic retroperitoneal fibrosis

Idiopathic retroperitoneal fibrosis (RPF) is characterized by the development of a fibrotic mass surrounding the abdominal aorta and its branches, of unknown aetiology. Several immunological mechanisms can be operative in the pathogenesis of RPF. Based on this assumption we treated a patient affected by idiopathic RPF with low-dose methotrexate (MTX) therapy. To our knowledge this is the first example of the effectiveness and safety of a long-term low-dose MTX treatment in the post-surgical management of RPF.

Lupus erythematosus panniculitis: an immunohistochemical study

An immunohistochemical study on a case of lupus erythematosus panniculitis (LEP), without discoid lupus erythematosus (DLE) or systemic lupus erythematosus (SLE) signs, showed that the cells in skin infiltrates were immunologically committed lymphocytes (OKT4, OKT8, OKT11 and HLA-DR positive cells) and elements of the monocyte-macrophage lineage (Leu M3 and Leu M5 positive). No immunophenotypically identifiable B-lymphocytes were seen. Immunofluorescent IgG, IgM, C3 and C4 deposits were found in blood vessel walls of the deep dermis. These findings, similar to that described in the skin changes of SLE and DLE, suggest that immunological mechanisms are operative in localized LEP, where the dermal lesions are the only expression of the disease.

One year treatment with low dose methotrexate in rheumatoid arthritis: effect on class specific rheumatoid factors

We evaluated the effect of a one-year treatment of low dose methotrexate (MTX) on class specific rheumatoid factors in 27 patients with rheumatoid arthritis (RA). Enzyme-linked immunosorbent assay (ELISA) showed after 6 and 12 months a significant reduction of IgM-RF, IgA-RF and IgG-RF levels from the baseline values. During MTX treatment, changes of each RF isotype were not correlated with any other isotype and its corresponding immunoglobulin changes. Moreover, immunological changes were not related to the improvement of clinical parameters. Our results showed that low dose MTX can specifically affect levels of RF isotypes, which are involved in the immune pathogenesis of RA.

Sternoclavicular joint disease in psoriatic arthritis

The radiological and tomographic aspects of the sternoclavicular joint were examined in 10 patients with psoriatic arthritis to evaluate better how this joint was affected using different radiological techniques. Imaging of the sternoclavicular joint showed that computed tomography provides a better visualisation of erosions, subchondral cysts, and sclerosis than standard radiography and conventional linear tomography.

Sonographic evaluation of femoral condylar cartilage in osteoarthritis and rheumatoid arthritis

Employing a real-time sonographic scanner with a 5 MHz linear probe, the articular cartilage of the knee was studied in four groups of subjects: normal subjects aged 18-36 years and 50-63 years, patients with rheumatoid arthritis (RA) and patients with osteoarthritis (OA). Cartilage thickness was diminished both in RA and in OA knees compared to the two groups of normal joints, even if in RA the reduction was less. The cartilage surface appeared irregular more frequently in OA than in RA. Our survey suggests that the sonographic technique is a useful, non-invasive diagnostic method to study the articular cartilage of the knee.

Avascular necrosis of the femoral head in long-term follow-up of systemic sclerosis: report of two cases

A long-term follow-up of two patients with scleroderma (SS) who developed a polyarthritis with bilateral femoral head osteonecrosis is reported. The severe parallel evolution of the small and large joint lesions and the late appearance of osteonecrotic changes in our patients suggest that avascular osteonecrosis is related to the osteoarticular progression of the longstanding SS.

[Fibroblastic rheumatism of the elderly. Histopathological, ultrastructural data and problems of differential diagnosis]

In order to contribute to the knowledge and the nosography of fibroblastic rheumatism, the authors report a case occurring in 68 years old patient. The differential diagnosis of the disease rests on histological and ultrastructural aspects of the dermal and articular tissues where numerous myofibroblasts are observed. On that score, among the acquired adult fibromatoses, fibroblastic rheumatism seems closer to Dupuytren's disease than to sclerodermis.

Phenotypic profile of major synovial cell populations in longstanding psoriatic arthritis

Monoclonal antibody investigations showed that the vast majority of cells infiltrating the synovial tissue of 8 patients with longstanding psoriatic arthritis stained for both mononuclear phagocyte and class II major histocompatibility (MHC) antigens and were therefore referred to as type I synoviocytes. A minor though consistent number of cells bore solely class II MHC antigens and were recognized as type II synoviocytes, a subpopulation that has been reported to be characteristically augmented in immune synovitides. In contrast, no immunophenotypically identifiable lymphoid cells were seen. It is suggested that type I and II synoviocytes represent the late phase of the phlogistic process and contribute to maintaining the tissue injury.