Reactive arthritis in a population exposed to an extensive waterborne gastroenteritis outbreak after sewage contamination in Pirkanmaa, Finland.

OBJECTIVES: To assess the occurrence, clinical picture, and triggering infections of reactive arthritis (ReA) associated with a large waterborne gastroenteritis outbreak. METHODS: After an extensive sewage contamination of the water supply system, an estimated 8453 of the 30 016 inhabitants of the town of Nokia fell ill. General practitioners and occupational physicians were advised to refer any patients with suspicion of new ReA to rheumatological examination including faecal culture, human leucocyte antigen (HLA)-B27 and antibody tests for Campylobacter, Salmonella, and Yersinia. RESULTS: Forty-five patients (33 females, 12 males) aged 16-77 years (median 53) were referred. ReA was diagnosed in 21, postinfectious arthralgia in 13, and other musculoskeletal conditions in 11 patients. HLA-B27 was positive in five out of 44 patients (11%). Of the 21 patients with ReA, possible triggering infections were observed in seven (33%), Campylobacter in four, Yersinia in three, and Salmonella in one, who also had Campylobacter infection. ReA was mild in all but one patient who presented with persistent Salmonella enterica serotype enteritidis infection. CONCLUSIONS: Taking into account the large population contaminated with potentially arthritogenic agents, the occurrence of ReA was rare and mild in character.

An extensive gastroenteritis outbreak after drinking-water contamination by sewage effluent, Finland.

An inappropriate cross-connection between sewage- and drinking-water pipelines contaminated tap water in a Finnish town, resulting in an extensive waterborne gastroenteritis outbreak in this developed country. According to a database and a line-list, altogether 1222 subjects sought medical care as a result of this exposure. Seven pathogens were found in patient samples of those who sought treatment. To establish the true disease burden from this exposure, we undertook a population-based questionnaire investigation with a control population, infrequently used to study waterborne outbreaks. The study covered three areas, contaminated and uncontaminated parts of the town and a control town. An estimated 8453 residents fell ill during the outbreak, the excess number of illnesses being 6501. Attack rates were 53% [95% confidence interval (CI) 49.5-56.4] in the contaminated area, 15.6% (95% CI 13.1-18.5) in the uncontaminated area and 6.5% (95% CI 4.8-8.8) in the control population. Using a control population allowed us to differentiate baseline morbidity from the observed morbidity caused by the water contamination, thus enabling a more accurate estimate of the disease burden of this outbreak.

Th2 cytokine genotypes are associated with a milder form of primary Sjogren's syndrome.

BACKGROUND: Immunohistological studies on salivary and lacrimal glands have yielded conflicting results on the Th1/Th2 balance in primary Sjögren's syndrome (pSS). OBJECTIVE: To establish whether pSS is a Th1 or Th2 directed autoimmune disease by analysing the polymorphism of the genes encoding for cytokines involved in the regulation of Th1/Th2 differentiation. METHODS: The polymorphisms of the genes encoding for interleukin 4 (IL4) -590 C/T, interleukin 13 (IL13) +2044 G/A, and interferon gamma (IFNG) +874 T/A were analysed in 63 white Finnish patients with pSS (61 female, two male) and in 63 healthy controls. The clinical and immunological data on the pSS patients were analysed in relation to these cytokine gene polymorphisms. RESULTS: There were no significant differences in the genotype or allele frequencies of IL4 -590, IL13 +2044, or IFNG +874 between pSS patients and controls. The erythrocyte sedimentation rate and concentrations of serum IgA and serum beta2 microglobulin were lower in pSS patients carrying the IL4 -590 T allele or the IL13 +2044 A allele than in those not carrying the respective alleles. The IL4 -509 T allele and IL13 +2044 A allele carriers less often had purpura than the corresponding non-carriers. CONCLUSIONS: The frequencies of the cytokine genotypes regulating Th1/Th2 differentiation did not differ between pSS patients and controls. However, the presence of cytokine genotypes with increased susceptibility to atopic and other Th2 diseases was associated with signs of a milder form of pSS. This finding would favour a hypothesis envisaging pSS as primarily a Th1 mediated autoimmune disease.

Matrix metalloproteinase 9 (MMP-9) gene polymorphism and MMP-9 plasma levels in primary Sjogren's syndrome.

OBJECTIVES: To determine whether plasma matrix metalloproteinase 9 (MMP-9) and MMP9 (-1562C-->T) polymorphism have an effect on the disease phenotype in primary Sjogren's syndrome (pSS). METHODS: Plasma MMP-9 concentrations and polymorphism of the MMP9 gene were analysed in 66 patients with pSS. These data were studied in relation to the clinical data of the patients. The genetic data of patients were compared with the data of 66 healthy subjects. RESULTS: Plasma MMP-9 was higher in patients with definite pSS than in patients with possible pSS. This association was principally caused by higher plasma MMP-9 in patients with a positive Schirmer test and keratoconjunctivitis sicca. pSS patients with purpura, SS-A autoantibodies and RF had significantly lower plasma MMP-9 than patients without these characteristics. The overall MMP9 (-1562C-->T) allele frequencies were similar in patients and control subjects. The frequency of the allele T was higher in patients without Raynaud's phenomenon than in the control group. CONCLUSIONS: MMP9 (-1562C-->T) could not be used for risk assessment in pSS. The presence of the rarer allele T may decrease the risk of Raynaud's phenomenon in pSS. High plasma MMP-9 is indicative of definite pSS but may paradoxically have a preventive effect on the eruption of purpura and on the development of autoantibody reaction in pSS.

Presence of apolipoprotein E epsilon4 allele predisposes to early onset of primary Sjogren's syndrome.

BACKGROUND: Apolipoprotein E (apoE) polymorphism plays a central role in lipid metabolism, but has recently also been suggested to regulate inflammation, as judged by levels of serum C-reactive protein (CRP). OBJECTIVE: To establish whether polymorphism of the apoE genes affects susceptibility to primary Sjogren's syndrome (pSS), degree of inflammation or age of onset of pSS. METHODS: ApoE genotype distribution and allelic frequencies were analysed using PCR and the TaqMan system in 63 Finnish Caucasian patients with pSS and in 64 healthy controls matched for sex, ethnic origin and area of residence. The clinical and immunological data on the pSS patients were analysed in relation to the apoE genotypes. RESULTS: There was no difference between pSS patients and controls in apoE genotype and allelic frequencies. The apoE epsilon4 allele was significantly associated with early onset of pSS in the entire population and in female patients (Kaplan-Meier log rank test, P = 0.0407 and P = 0.0168, respectively). The average age (+/- S.D.) of onset of pSS in all apoE epsilon4 allele carriers was 46 +/- 12 and in other genotypes it was 53 +/- 10 yr (P = 0.031, t-test). ApoE polymorphism was not associated with signs of inflammation evaluated by such markers as concentration of plasma CRP, plasma interleukin-6, plasma TNF-alpha, immunoglobulin G and haemoglobin, or leucocyte count or ESR. CONCLUSIONS: ApoE polymorphism does not affect susceptibility to pSS or levels of plasma inflammatory indices in patients with pSS. However, a clear association prevails between apoE epsilon4 and early onset of pSS.

Treatment of hyperphosphatemia, secondary hyperparathyroidism and hypocalcemia with calcium carbonate favorably modulates vaccination response in uremic rats.

AIMS: Immune dysfunction is characteristic of renal failure, leading to suboptimal antibody generation and increased susceptibility to infections. We tested whether the treatment of uremic phosphate retention by increased calcium carbonate intake will beneficially influence vaccination response in 5/6-nephrectomized rats. METHODS: The nephrectomized (uremic) and sham-operated (control) rats were either fed 0.3% calcium diet (NTX and Sham groups, respectively) or 3% high-calcium diet (Ca-NTX and Ca-Sham groups). All rats were immunized with tetanus toxoid 6 weeks after the operations, and antitoxin levels were measured 7 weeks later. RESULTS: Plasma creatinine was significantly elevated after the nephrectomy: the values (mean +/- SD) in the NTX (n = 16), Ca-NTX (n = 11), Sham (n = 14) and Ca-Sham (n = 8) groups were 97 +/- 14, 93 +/- 17, 66 +/- 7, and 69 +/- 8 micromol/l, respectively. The NTX group developed phosphate retention and secondary hyperparathyroidism, which were completely prevented by the high calcium diet. The mean tetanus antitoxin concentrations of the groups were: NTX 0.25 +/- 0.32; Ca-NTX 0.45 +/- 0.44; Sham 0.58 +/- 0.24 and Ca-Sham 0.64 +/- 0.25 IU/ml (log of geometric mean concentration). The antibody response in the NTX group was significantly lower, i.e. 43% of that in the Sham group (p = 0.003), while the response in the Ca-NTX group was not different from that in the Sham group. The tetanus response of all the uremic rats inversely correlated with the plasma levels of phosphate (r = 0.447, p = 0.02), parathormone (r = -0.409, p = 0.03) and creatinine (r = 0.578, p = 0.002). DISCUSSION: We conclude that renal failure impairs vaccination response in rats, the impairment of which can be favorably modulated by phosphate-binding and PTH-suppressing high-calcium diet.

The significance of mannan-binding lectin gene alleles in patients with primary Sjögren's syndrome.

OBJECTIVE AND METHODS: To investigate the significance or mannan-binding lectin (MBL) gene alleles in patients with primary Sjogren's syndrome (pSS). Genotypes were determined in 65 pSS patients and 138 controls. RESULTS: No difference in MBL genotype or allele frequencies was detected between the pSS patients and controls. However, when the effect of MBL genotypes on the diagnostic findings in pSS patients was assessed, none of the eight patients with 52/w genotype fulfilled four (definite) Californian criteria (P = 0.007). Among these eight the Chisholm-Mason histological grade was > or = 3 in only three (P = 0.017). Furthermore, the MBL concentration was lower in patients with 52/w genotype compared to those with wild-type (w/w) genotype (P = 0.035). CONCLUSION: Our findings suggest that MBL structural gene polymorphisms do not influence on susceptibility to pSS. However, MBL may be associated with salivary gland destruction in pSS, and its concentration may be comparable with the intensity of inflammatory reaction. Further studies are warranted to clarify the possible mechanisms involved.

Elevated interleukin-6 plasma levels are regulated by the promoter region polymorphism of the IL6 gene in primary Sjögren's syndrome and correlate with the clinical manifestations of the disease.

OBJECTIVES: To determine whether plasma interleukin-6 (IL-6) and G/C base exchange polymorphism at position -174 of the IL6 gene have an effect on the clinical manifestations of primary Sjögren's syndrome (pSS). METHODS: Levels of circulating IL-6 protein and polymorphism of the IL6 gene were analysed in 66 patients with pSS and in 400 healthy subjects. These data were studied in relation to clinical data on the pSS patients. RESULTS: Plasma IL-6 was elevated in pSS patients compared with healthy controls. pSS patients with coeliac disease, pulmonary fibrosis or alveolitis or peripheral nervous system symptoms had significantly higher IL-6 levels than patients without these manifestations. IL-6 levels increased in parallel with the histological grade of minor salivary gland biopsy and the number of pSS criteria fulfilled. IL6 allele frequencies were similar in patients and normal subjects. Plasma IL-6 levels were regulated by the IL6 genotype in pSS patients. CONCLUSIONS: The G/C polymorphism of the IL6 gene does not predispose patients to pSS, but the circulating IL-6 concentration is related to specific manifestations of the disease and the levels of IL-6 are regulated by the IL6 promoter polymorphism in pSS.

Genetic association between interleukin-10 promoter region polymorphisms and primary Sjögren's syndrome.

OBJECTIVE: To determine whether the haplotypes formed on the basis of single-base-exchange polymorphisms at positions -1082, -819, or -592 of the interleukin-10 (IL-10) gene predispose subjects to primary Sjögren's syndrome (SS). METHODS: The frequency of IL-10 polymorphisms was analyzed in 62 patients with primary SS and in 400 healthy subjects. These data were assessed for correlations with the concentration of IL-10 in the plasma. RESULTS: The frequency of the IL-10 GCC haplotype (G at position -1082, C at position -819, and C at position -592 of the IL-10 gene) was increased (P < 0.05, odds ratio [OR] 1.90, 95% confidence interval [95% CI] 0.955-3.62) and the frequency of the ACC haplotype decreased (P < 0.05, OR 0.443, 95% CI 0.257-0.764) in primary SS patients compared with healthy controls. Moreover, the frequency of the ATA haplotype was similar in primary SS patients and healthy controls, but the incidence of the GCC/ATA genotype was elevated in the primary SS patients (P < 0.05, OR 2.19, 95% CI 1.19-4.03). The concentration of plasma IL-10 was significantly higher in patients carrying the GCC haplotype than in non-carriers of GCC. CONCLUSION: These results suggest that the presence of the GCC haplotype or the GCC/ATA genotype and the absence of the ACC haplotype of the IL-10 gene are associated with an increased susceptibility to primary SS. This effect is probably mediated by the increased capability to produce IL-10 among carriers of the GCC haplotype.

Constant, but not pulsed calcitriol suppresses hemodialysis patients' antigen-induced lymphocyte proliferation.

BACKGROUND/AIMS: In vitro constant calcitriol [1,25-(OH)(2)D(3)] inhibits healthy individuals' T lymphocyte proliferation at supraphysiological concentrations. In contrast, among hemodialysis patients, intravenous 1,25-(OH)(2)D(3) pulse therapy of secondary hyperparathyroidism has been shown to be even immunostimulatory. We studied the effect of in vitro constant and intermittent 1, 25-(OH)(2)D(3) on lymphocyte antigen response of hemodialysis patients. METHODS: Twelve hemodialysis patients' peripheral blood mononuclear cells were stimulated with purified protein derivative of tuberculin (12.5, 25 and 50 mg/l) or tetanus toxoid (TT; 1,000, 5, 000 and 10,000 Lf/l, limit of flocculation) for 7 days. Constant 1, 25-(OH)(2)D(3) was added to all cultures at concentrations of 0, 10(-10) or 0.25 x 10(-9) mol/l (0, 42 and 105 ng/l) and to half of the cultures additionally as a 0.75 x 10(-9) mmol/l (315-ng/l) pulse on the 5th culture day. RESULTS: TT-induced lymphocyte proliferation was statistically related to a constant 1,25-(OH)(2)D(3) concentration (p = 0.001, analysis of variance). With constant 1, 25-(OH)(2)D(3) concentrations of 0, 42 and 105 ng/l, the TT-induced responses were 1.53, 1.44 and 1.40 log cpm, respectively (mean of TT concentrations). The responses of the (additionally) pulse-treated cells [1.65, 1.50 and 1.40 log cpm; concentrations of constant 1, 25-(OH)(2)D(3) as above] were similar to those of the nonpulsed cells. Thus constant, but not pulsed 1,25-(OH)(2)D(3) decreased the TT responses. On the purified protein derivative of tuberculin response, neither constant nor pulsed 1,25-(OH)(2)D(3) had any significant effect. CONCLUSIONS: The decline of TT response with constant 1,25-(OH)(2)D(3) corresponds with findings on immunosuppressive action of 1,25-(OH)(2)D(3) in previous studies done on normal subjects' cells. This was not seen with intermittently applied 1,25-(OH)(2)D(3). These results support the previous concept that intermittent 1,25(OH)(2)D(3) therapy is not immunosuppressive in hemodialysis patients.

Adequate seroresponse to influenza vaccination in dialysis patients.

BACKGROUND: Hemodialysis (HD) patients are immunocompromised, and they have been shown to react suboptimally to recommended vaccinations. Advances in dialysis therapy and other supportive measures may theoretically result in better immune system functions. Clinical evidence supporting this theory has, however, not been presented. With influenza vaccination response, we tried to address this question. METHODS: 42 HD and 15 continuous ambulatory peritoneal dialysis (CAPD) patients were vaccinated with a trivalent influenza vaccine, and the seroresponses at 5 weeks were measured. The results were compared with those of similarly vaccinated 20 nephrology outpatient clinic patients with varying degrees of renal insufficiency and those of 31 cardiac patients with normal renal function. RESULTS: The dialysis patients had higher prevaccination titers of hemagglutination-inhibiting (HI) antibodies to all three vaccine virus antigens than the other groups due to more frequent previous vaccinations. The dialysis patients exhibited lower antibody increases, but an almost comparable proportion of them reached a protective antibody level (HI titers > or =40) 5 weeks after vaccination [A/H3N2: 61% (cardiac patients), 35% (nephrology outpatient clinic patients), 67% (CAPD), and 36% (HD); A/H1N1: 71, 70, 80 and 60; B: 97, 90, 80, and 76%, respectively]. Among the HD group, all patients receiving parenteral calcitriol except 1 (83%), but only 50% of the other HD patients produced protective antibody titers at least to two out of three vaccine virus antigens. No other patient- or HD treatment-associated parameter was significantly related to the vaccination-induced antibody response. CONCLUSIONS: We conclude that influenza vaccination of dialysis patients according to current recommendations may be effective. Additionally, our results suggest that parenteral calcitriol treatment may augment the immune response of HD patients even in a clinically relevant way, an effect so far shown only in in vitro studies.

Increased in vitro production of interleukin 6 in response to trimethoprim among persons with trimethoprim induced systemic adverse reactions.

OBJECTIVE: Trimethoprim occasionally triggers a systemic adverse reaction including fever, malaise, head and backache, and even overt meningeal irritation, particularly in women with an autoimmune rheumatic disease. To study the unknown pathogenesis of the reaction we measured the effect of trimethoprim upon the cytokine [interleukin (IL) 2, 6, 10, and tumor necrosis factor-alpha] production of trimethoprim reactive and tolerant persons' peripheral blood mononuclear cells in vitro. METHODS: Peripheral blood mononuclear cells from 12 women reactive to trimethoprim (3 with primary Sjögren's syndrome, 3 with systemic lupus erythematosus, 1 with systemic scleroderma, 5 with no rheumatic disease) were cultured in the presence of trimethoprim, and the cytokine production was measured. Eleven women who tolerated trimethoprim (6 with Sjögren's syndrome and 5 with no rheumatic disease) served as controls. RESULTS: Therapeutic trimethoprim concentration induced in the mononuclear cells of the trimethoprim reactive patients significantly higher IL-6 production [mean +/- SD (median), 2034+/-2965 (572) pg/ml] versus cells of the trimethoprim tolerant subjects [954+/-2552 (89) pg/ml; p = 0.036]. No significant differences in the production of other cytokines were detected. CONCLUSION: Trimethoprim induces IL-6 production in the peripheral blood mononuclear cells of trimethoprim reactive persons. We suggest that IL-6 production is the probable trigger leading to the clinical reaction.

Adverse drug reactions in Sjögren's syndrome. Frequent allergic reactions and a specific trimethoprim-associated systemic reaction.

Trimethoprim-associated systemic reactions, including aseptic meningitis, have been reported to be very rare adverse drug reactions. Patients with Sjögren's syndrome have been overrepresented, but no epidemiological surveys of the reaction have been conducted. To study the overall frequency of adverse drug reactions, and especially trimethoprim-associated reactions, we interviewed 85 primary Sjögren's syndrome patients and compared the results with those of 45 similarly interviewed osteoarthritis patients. Antimicrobial allergy was more common among Sjögren's syndrome patients than in osteoarthritis patients (46% vs. 27%). Eleven Sjögren's syndrome patients (13%), but no osteoarthritis patient, had experienced at least a partial, non-allergic systemic reaction with trimethoprim. Of them five (6%) had had a full-blown systemic reaction including both chills/fever and headache/backache and at least one of the following: malaise, vomiting, dizziness, confusion or meningeal irritation. Our findings confirm that allergic reactions to antimicrobials are frequent in Sjögren's syndrome. In addition to allergic reactions Sjögren's syndrome patients are prone to a specific trimethoprim-associated systemic reaction. This should be remembered when prescribing antimicrobials.

Severe antibody-mediated human insulin resistance: successful treatment with the insulin analog lispro. A case report.

OBJECTIVE: To evaluate the efficacy of the insulin analog lispro (Lys B28, Pro B29) in severe insulin resistance caused by human insulin antibodies. CASE: A 27-year-old man with a history of diabetes treated with human insulin for 3 years developed severe immunological insulin resistance caused by human insulin antibodies. Throughout follow-up (12 months) the insulin analog lispro was administered with an infusion pump as the only insulin therapy. The insulin dose decreased from an average of 300 U/day to 58 U/day, HbA1c decreased from 12.6 to 7.4%, and human insulin antibodies decreased from 8,057 to 1,860 nU/ml. Hypoglycemic episodes during early morning disappeared. CONCLUSIONS: The insulin analog lispro might be suitable for the treatment of diabetic patients with substantially increased insulin antibody levels Apparently, the structural difference between the lispro and human insulin molecules prevented lispro from binding to the human insulin antibodies in this patient and consequently was nonimmunogenic.

Intravenous calcitriol therapy restores reduced antigen-induced T-lymphocyte response in 1,25-(OH)2D3-deficient hemodialysis patients.

Ten hemodialysis patients were treated with intravenous calcitriol (1-1.5 micrograms 3 times per week) for 3 months and parameters reflecting cell-mediated immunity were measured before and at the end of treatment. Peripheral blood CD4+ cells increased from 33.1 +/- 14.2 to 43.8 +/- 5.8% (p < 0.05) causing a comparable increase in CD3+ cells (67.3 +/- 14.3 vs. 77.1 +/- 7.9%, p < 0.05), whereas CD8+ cells did not change significantly (22.2 +/- 5.4 vs. 25.5 +/- 3.0%). Mitogen-induced lymphocyte stimulation responses were normal even before treatment and did not change. Antigen-induced T-cell responses were very heterogeneous before calcitriol therapy; those 5 with initially unmeasurably low serum 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) had a weaker response than the other patients (3,873 +/- 1,528 vs. 22,948 +/- 13,684 cpm, p < 0.05). After calcitriol treatment the patients with pretherapy unmeasurably low serum 1,25-(OH)2D3 had a comparable response to other patients (16,220 +/- 9,674 vs. 22,064 +/- 10,331 cpm). Our study shows that calcitriol therapy restores the depressed antigen-induced T-cell response of the hemodialysis patients most deficient in 1,25-(OH)2D3.