Low copy numbers of complement C4 and C4A deficiency are risk factors for myositis, its subgroups and autoantibodies

BACKGROUND

Idiopathic inflammatory myopathies (IIM) are a group of autoimmune diseases characterised by myositis-related autoantibodies plus infiltration of leucocytes into muscles and/or the skin, leading to the destruction of blood vessels and muscle fibres, chronic weakness and fatigue. While complement-mediated destruction of capillary endothelia is implicated in paediatric and adult dermatomyositis, the complex diversity of complement C4 in IIM pathology was unknown.

METHODS

We elucidated the gene copy number (GCN) variations of total C4, C4A and C4B, long and short genes in 1644 Caucasian patients with IIM, plus 3526 matched healthy controls using real-time PCR or Southern blot analyses. Plasma complement levels were determined by single radial immunodiffusion.

RESULTS

The large study populations helped establish the distribution patterns of various C4 GCN groups. Low GCNs of C4T (C4T=2+3) and C4A deficiency (C4A=0+1) were strongly correlated with increased risk of IIM with OR equalled to 2.58 (2.28-2.91), p=5.0×10^-53 for C4T, and 2.82 (2.48-3.21), p=7.0×10^-57 for C4A deficiency. Contingency and regression analyses showed that among patients with C4A deficiency, the presence of HLA-DR3 became insignificant as a risk factor in IIM except for inclusion body myositis (IBM), by which 98.2% had HLA-DR3 with an OR of 11.02 (1.44-84.4). Intragroup analyses of patients with IIM for C4 protein levels and IIM-related autoantibodies showed that those with anti-Jo-1 or with anti-PM/Scl had significantly lower C4 plasma concentrations than those without these autoantibodies.

CONCLUSIONS

C4A deficiency is relevant in dermatomyositis, HLA-DRB1*03 is important in IBM and both C4A deficiency and HLA-DRB1*03 contribute interactively to risk of polymyositis.

306. CD8+ T-Cell Responses to Chronic Hepatitis C in Pregnancy

Background

Chronic hepatitis C virus (HCV) infection is marked by stable, high -level viremia and a failed T-cell response. HCV-specific CD4+ helper T cells are rare, and CD8+ cytotoxic T cells are functionally exhausted or ineffective due to viral escape mutations. Postpartum, a subset of infected women experience a substantial drop in viremia. Preliminary data indicate that this unusual viral decline may be linked to a resurgence of HCV-specific CD4+ T cells producing Th1 cytokines. How improved CD4+ helper T-cell function might affect viral replication in this scenario is not established. Here we tested the hypothesis that improved CD4+ T cell help mediates control of chronic HCV replication through enhanced CD8+ T-cell function.

Methods

We examined plasma HCV RNA viral load (VL) and HCV-specific T-cell responses in 33 women with chronic HCV during the third trimester (T3) and at 3 months postpartum (3P). HCV-specific CD4+ and CD8+ T-cell IL2 and IFNγ responses were measured by intracellular cytokine staining following stimulation of peripheral blood mononuclear cells with peptide pools corresponding to the HCV proteins NS3, NS4a, and NS4B.

Results

Median VL dropped from 5.87 log₁₀ at T3 to 5.25 log₁₀ at 3P (P < 0.0001, Wilcoxson signed rank), with a wide range from +0.4 log₁₀ to -4.2 log₁₀. The degree of decline correlated significantly with improved frequencies of HCV-specific CD4+ T cells producing IFNγ (P = 0.015 Spearman) but did not correlate with CD8+ T-cell changes. Nevertheless, improved T helper function correlated with increased HCV-specific CD8+ T-cell function (ΔCD4+IL2+ vs. ΔCD8+IFNγ+, P = 0.015 Spearman, graph 1; ΔCD4+IFNγ+ vs. CD8+IFNγ+ at 3P, P = 0.004 Spearman, graph 2).

Conclusion

Despite no significant association between virus-specific CD8+ T-cell Tc1 cytokine production and postpartum viral control, our data suggest that recovery of CD4+ T-cell help may augment CD8+ T-cell function. Further study incorporating viral genomic sequences to focus on intact class I epitopes is needed to clarify the relationship of improved CD8+ function and viral control in this unique model of immune restoration.

Disclosures

All authors: No reported disclosures.

A controlled trial of two forms of self-management education for adults with asthma

PURPOSE

Excess morbidity and mortality due to asthma, aggravated by demonstrably poor patient self-management practices, suggest the need for formal patient education programs. Individual and group asthma education programs were developed and evaluated to determine their cognitive, behavioral, and clinical effects.

PATIENTS AND METHODS

We compared changes in asthma symptoms, utilization of medical services, knowledge about asthma, metered-dose inhaler (MDI) technique, and self-management behaviors for 323 adult Kaiser Permanente patients with moderate to severe asthma who were randomly assigned to small-group education, individual teaching, or 1 of 2 control conditions--an information (workbook) control or usual control (no formal asthma education). Data were collected from patients by questionnaire, diary, and physical examination at enrollment and at 5 months and 1 year after intervention. Medical record data on these patients were abstracted for a total 3-year period, from 1 year before to 2 years after enrollment.

RESULTS

Compared with the usual control, the self-management education programs were associated with significant improvements in control of asthma symptoms (reduced "bother" due to asthma and increased symptom-free days), MDI technique, and environmental control practices. Small-group education also was associated with significant improvements in physician evaluation of the patients' asthma status and in patients' level of physical activity. For both group and individual education recipients, improvement in MDI technique was positively correlated with improved control of symptoms; however, the degree of improvement in symptoms was greater than that which could be accounted for on the basis of improvement in MDI technique alone. The time course over which changes occurred in the various outcome measures suggests the mechanism by which education resulted in improvement in the patient's status. Significant improvements in MDI technique and environmental control practices were manifest immediately following education (5-month follow-up) and at the 1-year follow-up. Significant improvements in symptom measures were not apparent until the 1-year follow-up. The rate of utilization of medical care for acute exacerbations decreased between baseline and the 2-year follow-up period, but this decrease did not differ significantly among treatment conditions. However, there was a trend toward greater reduction in patients receiving small-group education. An ad hoc finding of a significant difference favoring small-group education between the baseline and the second follow-up year acute visit rates was observed. This result must be regarded as tentative, since it is not clear that unambiguous statistical significance is attained in the light of multiplicity issues. However, this trend is consistent with the antecedent benefits of the small-group education, and appears to warrant further investigation.

CONCLUSIONS

Carefully designed asthma education programs for adults can improve patients' understanding of their condition and its treatment and increase their motivation and confidence that the condition can be controlled, thereby increasing their adherence to the treatment regimen and management of symptoms, and, in turn, improving control of symptoms. Both small-group education and individual education were associated with significant benefits, but the group program was simpler to administer, better received by patients and educators, and more cost-effective. The results show promise for improving clinical outcomes, through well-designed educational programs, for patients with asthma and other chronic health problems.

An evaluation of approaches to asthma self-management education for adults: the AIR/Kaiser-Permanente Study

The purpose of the AIR/Kaiser-Permanente asthma project is to evaluate various approaches to the education of adults with asthma, identifying those types of patients for whom particular approaches are most cost effective. Critical self-management practices for adults with asthma were identified using the critical incident technique. An individualized and a group administered educational program are being developed to teach the identified critical skills, using the instructional models previously employed in AIR WISE and AIR POWER programs for children with asthma. Three hundred patients with moderate to severe asthma from Northern California Kaiser-Permanente Medical Group clinics will participate in a trial of these programs. Patients will be randomly assigned to one of four conditions: One of two educational programs, an information/attention control, or a data-only control condition. Data will be collected on all patients for 15 months; health care utilization data covering a two-year period will be available from medical records. Program effectiveness will be evaluated in terms of pre-post changes in the patients' knowledge, attitudes, self-management practices, medical condition, daily functioning, and utilization of services. Cost effectiveness will be evaluated, paying specific attention to the cost effectiveness of different educational approaches for different types of patients.