Paula Vähäsalo

A Prospective Study of the Role of Coxsackie B and Other Enterovirus Infections in the Pathogenesis of IDDM

Coxsackievirus B infections have been associated with clinical manifestation of insulin-dependent diabetes mellitus (IDDM) in several studies, but their initiating role in the slowly progressing β-cell damage is not known. This is the first prospective study designed to assess the role of coxsackie B and other enterovirus infections in the induction and acceleration of this process. Three separate series were studied: 1) an intrauterine exposure series comprising 96 pregnant mothers whose children subsequently manifested IDDM and 96 control mothers whose children remained nondiabetic; 2) a cohort of 22 initially unaffected siblings of diabetic children who were followed until they developed clinical IDDM (mean observation time, 29 months) and 110 control siblings who remained nondiabetic; 3) a case-control series comprising 90 children with newly diagnosed IDDM and 90 control subjects. Enterovirus infections were identified on the basis of significant increases in serum IgG, IgM, or IgA class antibodies against a panel of enterovirus antigens (capture radioimmunoassay). Enterovirus antibodies were significantly elevated in pregnant mothers whose children subsequently manifested IDDM, particularly in cases in which IDDM appeared at a very young age, before the age of 3 years (P < 0.005). Serologically verified enterovirus infections were almost two times more frequent in siblings who developed clinical IDDM than in siblings who remained nondiabetic (mean, 1.0 vs. 0.6 infections/follow-up year; P < 0.001). This difference was seen both close to the diagnosis of IDDM and several years before diagnosis. Up to 19% (10 of 52) of the infections in prediabetic siblings were associated with increases in islet cell antibody (ICA) levels, and 83% (10 of 12) of ICAs increase with enterovirus infections. The corresponding figures in control siblings were 3% (5 of 185, P < 0.001) and 38% (5 of 13, Ns). IgM class enterovirus antibodies were slightly elevated in young children (<3 years old)with newly diagnosed IDDM (P < 0.05), but not in older patients. These observations suggest that exposures to enterovirus infections, both in utero and in childhood, are able to induce β-cell damage and lead to clinical IDDM after a varying subclinical period.

Prediction of insulin-dependent diabetes mellitus in siblings of children with diabetes. A population-based study. The Childhood Diabetes in Finland Study Group.

An unselected population of 755 siblings of children with insulin-dependent diabetes mellitus (IDDM) was studied to evaluate the predictive characteristics of islet cell antibodies (ICA), antibodies to the IA-2 protein (IA-2A), antibodies to the 65-kD isoform of glutamic acid decarboxylase (GADA), insulin autoantibodies (IAA), and combinations of these markers. We also evaluated whether the histochemical ICA test could be replaced by the combined detection of other markers. 32 siblings progressed to IDDM within 7.7 yr of the initial sample taken at or close to the diagnosis of the index case (median follow-up, 9.1 yr). The positive predictive values of ICA, IA-2A, GADA, and IAA were 43, 55, 42, and 29%, and their sensitivities 81, 69, 69, and 25%, respectively. In contrast to the other three antibody specificities, GADA levels were not related to the risk for IDDM. The risk for IDDM in siblings with four, three, two, one, or no antibodies was 40, 70, 25, 2, and 0.8%, respectively. Combined screening for IA-2A and GADA identified 70% of all ICA-positive siblings, and all of the ICA-positive progressors were also positive for at least one of the three other markers. The sensitivity of the combined analysis of IA-2A and GADA was 81%, and the positive predictive value was 41%. In conclusion, combined screening for IA-2A and GADA may replace the ICA assay, giving comparable sensitivity, specificity, and positive predictive value. Accurate assessment of the risk for IDDM in siblings is complicated, as not even all those with four antibody specificities contract the disease, and some with only one or no antibodies initially will progress to IDDM.

Infliximab or etanercept in the treatment of children with refractory juvenile idiopathic arthritis: an open label study

Objective: To study infliximab and etanercept in the treatment of refractory juvenile idiopathic arthritis (JIA). Methods: In a non-randomised, prospective, open label study, 24 patients (mean age 10.2 years, range 3.3–16.3) with polyarticular JIA were treated with either infliximab (n=14) or etanercept (n=10). The patients had had active polyarthritis for at least one year and standard treatment had failed. Anti-tumour necrosis factor (TNF) treatment was added to the current drug treatment. Infliximab (3–4 mg/kg) was given intravenously at weeks 0, 2, and 6, and thereafter at 4 to 8 week intervals. Etanercept (0.4 mg/kg) was given subcutaneously twice a week. Improvement of the patients was assessed at 3, 6, and 12 months according to established JIA response criteria. Results: In intention to treat analyses, patients in both treatment groups improved significantly. ACR Paediatric 50 was achieved at 3, 6, and 12 months by 9/10 (90%), 8/9 (89%), and 8/9 (89%) patients with etanercept and by 8/12 (67%), 10/12 (83%), and 7/9 (78%) with infliximab, respectively. At 12 months, ACR Paediatric 75 was achieved by 67% of patients in both treatment groups. Five withdrawals due to adverse effects or lack of efficacy occurred in the infliximab group and one due to lack of compliance in the etanercept group. Conclusion: In this open label clinical study of active JIA, both infliximab and etanercept provided a significant rapid and sustained reduction in disease activity. Adequately powered randomised controlled trials are needed to elucidate the long term safety and efficacy of TNF modulators in the treatment of JIA.

IA-2 antibodies - a sensitive marker of IDDM with clinical onset in childhood and adolescence

Summary To study the relationship of IA-2 antibodies (IA-2A) to other autoantibodies and genetic risk markers in insulin-dependent diabetes mellitus (IDDM), 758 children and adolescents younger than 15 years of age (mean age 8.4 years) with newly diagnosed diabetes were analysed for IA-2A, GAD antibodies (GADA) and insulin autoantibodies (IAA) with radiobinding assays, for islet cell antibodies (ICA) with immunofluorescence and for HLA DR alleles by serology. IA-2A were detected in 85.9 % of cases with no association with gender or age. An overwhelming majority of the patients (71.3 %) tested positive for three or more antibodies, and 90.7 % for at least two. Fifty-four subjects (7.1 %) had one antibody detectable, whereas only 2.1 % of the patients tested negative for all four. A higher proportion of patients was positive for IA-2A and/or GADA than for ICA alone (95.5 vs 84.2 %, p < 0.001). The prevalence and level of IA-2A were increased in cases carrying HLA DR4/non-DR3 compared with other DR combinations. The results indicate that almost all patients with newly diagnosed childhood IDDM can be identified by screening with these four autoantibodies. The combination of IA-2A and/or GADA had a higher sensitivity for IDDM than ICA alone. The close association between IA-2A and HLA DR4, the strongest single allele predisposing to IDDM, suggests that IA-2A may be a more specific marker of beta-cell destruction than GADA, which have been shown to associate with the DR3 allele and thyroid autoimmunity. [Diabetologia (1998) 41: 424–429]

Autoantibodies associated with Type I diabetes mellitus persist after diagnosis in children

Summary To study the persistence of Type I (insulin-dependent) diabetes mellitus associated autoantibodies and their relation to genetic risk markers and clinical characteristics of the disease after clinical manifestation, serum samples were obtained from 90 children and adolescents at diagnosis and 2, 5 and 10 years later. The samples were analysed for islet cell antibodies (ICA) by immunofluorescence and for antibodies to glutamic acid decarboxylase (GADA), intracellular portion of the protein tyrosine phosphatase related IA-2 antigen (IA-2A) and insulin autoantibodies by specific radiobinding assays. Of the subjects tested 79 % were positive for IA-2A at diagnosis, 62 % for GADA, 81 % for ICA and 28 % for insulin autoantibodies, but the prevalence of IA-2A, GADA and ICA decreased substantially as a function of increasing duration of the disease (p < 0.05 or less), their levels following the same pattern (p < 0.001 for all three autoantibodies). Two thirds of the subjects still tested positive for at least one autoantibody specificity after the first 10 years of the disease and 42 % had two or three antibodies detectable. An increase over the initial antibody concentrations after the diagnosis was seen more often for GADA than for ICA (p < 0.001) or IA-2A (p < 0.05). In conclusion, autoantibodies associated with Type I diabetes appear to persist longer than expected after manifestation of the clinical disease, possibly due to small scale continuous beta-cell regeneration after diagnosis or to structural and/or functional mimicry between exogenous proteins and beta-cell antigens or both. [Diabetologia (1998) 41: 1293–1297]

Several different enterovirus serotypes can be associated with prediabetic autoimmune episodes and onset of overt IDDM

In a prospective multicentre study described previously on prediabetic events in siblings of index cases with insulin‐dependent diabetes mellitus, 31 children developed clinical diabetes during the observation period and 51 children seroconverted for islet cell antibodies or insulin autoantibodies. By using nonserotype specific EIA and RIA, it has shown recently that enterovirus infections in both groups were frequently associated with increases of islet cell antibody and/or insulin autoantibody titres. Serum specimens sequentially collected from 12 children during the prediabetic period were still available and were then tested for serotype‐specific neutralizing antibodies. Plaque‐neutralization assays were carried out for coxsackievirus A9, coxsackievirus B types 1 to 6, and echovirus types 1 and 11. An unequivocal monotypic increase in neutralizing antibodies was observed on seven occasions in six children, on one occasion with coxsackievirus A9, one with coxsackievirus B1, two with coxsackievirus B2, two with coxsackievirus B3, and one with coxsackievirus B5. In four patients, the infection was associated temporally with increases in the levels of islet cell antibodies, insulin autoantibodies and/or antibodies to glutamic acid decarboxylase, and in three other patients, it coincided with the clinical onset of insulin‐dependent diabetes mellitus. These results suggest that the association of enterovirus infections with insulin‐dependent diabetes mellitus is not restricted to serotype 4 of coxsackie B viruses suspected previously, but that several different serotypes might play a role in the pathogenesis of the disease. J. Med. Virol. 56:74–78, 1998.

Aggressive Combination Drug Therapy in Very Early Polyarticular Juvenile Idiopathic Arthritis (ACUTE–JIA): a multicentre randomised open-label clinical trial

Objectives In juvenile idiopathic arthritis (JIA), the efficacy of very early disease-modifying drug therapy, synthetic or biological, is not well known. Three alternative strategies were compared for treating recent‑onset polyarticular JIA. Methods In a 54-week multicentre open-label clinical trial, 60 disease-modifying antirheumatic drug (DMARD)-naive patients aged 4–15 years were randomly assigned into three treatment arms. The efficacy of infliximab plus methotrexate (TNF) was compared to that of two synthetic therapies: methotrexate alone (MTX) and DMARD methotrexate, sulphasalazine and hydroxychloroquine in combination (COMBO). Primary endpoint was American College of Rheumatology paediatric 75% improvement (ACR Pedi 75). Secondary endpoints were inactive disease and safety. Results In 59 patients, mean (±SE) age at baseline was 9.6±0.4 years, duration of JIA 1.9±0.2 months and number of active joints 18±1. ACR Pedi 75 was achieved in 100% (19/19) of patients receiving TNF, 65% (13/20) on COMBO (95% CI 44% to 86%) and 50% (10/20) on methotrexate (95% CI 28% to 72%) p<0.0001. Thirteen patients receiving TNF (68%; 95% CI 47% to 89%) achieved inactive disease, whereas eight (40%; 95% CI 22% to 63%) on COMBO and five (25%; 95% CI 6% to 44%) on methotrexate did (p=0.002). Patients on TNF spent a mean 26 weeks (95% CI 18 to 34) with inactive disease, longer than did those receiving COMBO (13 weeks; 95% CI 6 to 20), or methotrexate (6 weeks; 95% CI 2 to 10). Serious adverse events were rare. Conclusion In early polyarticular JIA, targeting to achieve minimally active or inactive disease, infliximab plus methotrexate was superior to synthetic DMARD in combination and strikingly superior to methotrexate alone.

Predictive Characteristics of Diabetes-Associated Autoantibodies Among Children With HLA-Conferred Disease Susceptibility in the General Population

OBJECTIVE As data on the predictive characteristics of diabetes-associated autoantibodies for type 1 diabetes in the general population are scarce, we assessed the predictive performance of islet cell autoantibodies (ICAs) in combination with autoantibodies against insulin (IAAs), autoantibodies against GAD, and/or islet antigen 2 for type 1 diabetes in children with HLA-defined disease predisposition recruited from the general population. RESEARCH DESIGN AND METHODS We observed 7,410 children from birth (median 9.2 years) for β-cell autoimmunity and diabetes. If a child developed ICA positivity or diabetes, the three other antibodies were measured in all samples available from that individual. Persistent autoantibody positivity was defined as continued positivity in at least two sequential samples including the last available sample. RESULTS Pre-diabetic ICA positivity was observed in 1,173 subjects (15.8%), 155 of whom developed type 1 diabetes. With ICA screening, 86% of 180 progressors (median age at diagnosis 5.0 years) were identified. Positivity for four antibodies was associated with the highest disease sensitivity (54.4%) and negative predictive values (98.3%) and the lowest negative likelihood ratio (0.5). The combination of persistent ICA and IAA positivity resulted in the highest positive predictive value (91.7%), positive likelihood ratio (441.8), cumulative disease risk (100%), and specificity (100%). Young age at seroconversion, high ICA level, multipositivity, and persistent positivity for IAA were significant risk markers for type 1 diabetes. CONCLUSIONS Within the general population, the combination of HLA and autoantibody screening resulted in disease risks that are likely to be as high as those reported among autoantibody-positive siblings of children with type 1 diabetes.

Cow's milk consumption, disease-associated autoantibodies and Type 1 diabetes mellitus: A follow-up study in siblings of diabetic children

Evidence from case–control studies for the diabetogenicity of introduction of cow’s milk‐based formulas at early age in infancy is inconclusive. We followed siblings of children with Type 1 diabetes mellitus (Type 1 DM) to investigate a possible relationship between cow’s milk consumption during infancy or later in childhood and the emergence of diabetes‐associated autoantibodies and progression to clinical Type 1 DM. A cohort of 725 initially unaffected 0 to 25‐year‐old siblings of 801 index children with Type 1 DM diagnosed in 1986–1989 participated in the study (82 % of those invited). The siblings were observed for Type 1 DM associated autoantibodies at intervals of 3–12 months for 4 years, starting from the diagnosis of Type 1 DM in the index child. The follow‐up for Type 1 DM started at the same time and ended on 31 October 1995. The combined prevalence of Type 1 DM associated autoantibodies (islet cell antibodies (ICA), insulin autoantibodies (IAA), GAD autoantibodies (GADA), and/or antibodies to the insulinoma associated cDNA2 protein (IA‐2A)) was 13.6 % (95/697) at the beginning of the study. Of the initially seronegative siblings, 7.5 % (45/602) converted to antibody positivity during 4 years, and of all siblings 4.6 % (33/725) developed Type 1 DM during the total follow‐up time. The age at introduction of supplementary milk feeding was not significantly related to seroconversion to positivity for Type 1 DM associated autoantibodies or to the development of Type 1 DM in the siblings. When adjusted for age, sex, infant feeding patterns, and maternal age and education, high milk consumption in childhood (≥3 glasses daily) was associated with more frequent emergence of Type 1 DM‐associated autoantibodies than low consumption (<3 glasses daily) (adjusted odds ratio 3.97, 95 % confidence interval 1.3–11.7, p = 0.01). There was a non‐significant association between high milk consumption and progression to clinical Type 1 DM (adjusted hazard ratio 2.75, 95 % confidence interval 0.9–8.4, p = 0.07). To conclude, this study suggests that high consumption of cow’s milk during childhood may be associated both with seroconversion to positivity for diabetes‐associated autoantibodies and progression to clinical Type 1 DM among siblings of children with diabetes.

Impact of anti-TNF treatment on growth in severe juvenile idiopathic arthritis.

Objectives: To evaluate the impact of anti-tumour necrosis factor (TNF) treatment on growth and to identify the predictors for the change in growth in severe juvenile idiopathic arthritis (JIA). Methods: Data from 71 JIA patients (43 on etanercept, 28 on infliximab) were reviewed two years before and two years on the anti-TNF treatment. The patients had polyarticular disease course (48 polyarthritis, 19 extended oligoarthritis, two systemic arthritis, and two enthesitis related arthritis). At the initiation of the anti-TNF treatment, their mean age was 9.6 years and the mean duration of JIA, 5.7 years. Results: In the patients with delayed growth before anti-TNF treatment (n = 53), the growth velocity, measured as the change in height standard deviation score, accelerated +0.45 (95% confidence interval, 0.33 to 0.56) (p<0.001) during the anti-TNF treatment. In the patients with normal or accelerated growth before anti-TNF treatment (n = 18), the change in growth velocity was +0.05 (0.07 to 0.16) (p = 0.39). At two years on anti-TNF treatment, the growth velocity between these two groups was similar. No difference was found between the patients treated with etanercept or infliximab. A decelerating growth rate before the anti-TNF treatment was the strongest predictor for the observed increase in the growth velocity. The change in the inflammatory activity remained a significant predictor of the growth velocity even after the decrease in glucocorticoid dose was taken into account. Conclusions: In the treatment of polyarticular JIA, the anti-TNF treatment not only suppresses inflammation but also restores growth velocity.