The Paediatric Rheumatology International Trials Organization (PRINTO)

Reducing Immunogenicity by Design: Approaches to Minimize Immunogenicity of Monoclonal Antibodies

Monoclonal antibodies (mAbs) have transformed therapeutic strategies for various diseases. Their high specificity to target antigens makes them ideal therapeutic agents for certain diseases. However, a challenge to their application in clinical practice is their potential risk to induce unwanted immune response, termed immunogenicity. This challenge drives the continued efforts to deimmunize these protein therapeutics while maintaining their pharmacokinetic properties and therapeutic efficacy. Because mAbs hold a central position in therapeutic strategies against an array of diseases, the importance of conducting comprehensive immunogenicity risk assessment during the drug development process cannot be overstated. Such assessment necessitates the employment of in silico, in vitro, and in vivo strategies to evaluate the immunogenicity risk of mAbs. Understanding the intricacies of the mechanisms that drive mAb immunogenicity is crucial to improving their therapeutic efficacy and safety and developing the most effective strategies to determine and mitigate their immunogenic risk. This review highlights recent advances in immunogenicity prediction strategies, with a focus on protein engineering strategies used throughout development to reduce immunogenicity.

Association of ficolin-2 gene polymorphisms and susceptibility to systemic lupus erythematosus in Egyptian children and adolescents: a multicenter study

BACKGROUND

Pediatric-onset SLE (pSLE) is a multisystem autoimmune disease. Recently, the ficolin-2 (FCN2) gene has emerged as a potential candidate gene for susceptibility to SLE.

OBJECTIVES

The objective of this study was to evaluate the association of the FCN2 gene polymorphisms at positions -986 (G/A), -602 (G/A), -4 (A/G) and SNP C/T (rs3124954) located in intron 1, with susceptibility to pSLE in Egyptian children and adolescents.

METHODS

This was a multicenter study of 280 patients diagnosed with pSLE, and 280 well-matched healthy controls. The FCN2 promoter polymorphisms at -986 G/A (rs3124952), -602 G/A (rs3124953), -4 A/G (rs17514136) and SNP C/T (rs3124954) located in intron 1 were genotyped by polymerase chain reaction, while serum ficolin-2 levels were assessed using enzyme-linked immunosorbent assay.

RESULTS

The frequencies of the FCN2 GG genotype and G allele at -986 and -602 positions were significantly more represented in patients with pSLE than in controls (p < 0.001). Conversely, the FCN2 AA genotype and A allele at position -4 were more common in patients than in controls (p < 0.001). Moreover, patients carrying the FCN2 GG genotype in -986 position were more likely to develop lupus nephritis (odds ratio: 2.6 (95% confidence interval: 1.4-4.78); p = 0.006). The FCN2 AA genotype at position -4 was also identified as a possible risk factor for lupus nephritis (odds ratio: 3.12 (95% confidence interval: 1.25-7.84); p = 0.024).

CONCLUSION

The FCN2 promoter polymorphisms may contribute to susceptibility to pSLE in Egyptian children and adolescents. Moreover, the FCN2 GG genotype at position -986 and AA genotype at position -4 were associated with low serum ficolin-2 levels and may constitute risk factors for lupus nephritis in pSLE.

Comparison of Disease Characteristics, Organ Damage, and Survival in Patients with Juvenile-onset and Adult-onset Systemic Lupus Erythematosus in a Combined Cohort from 2 Tertiary Centers in Turkey

Objective.

Age at onset has been shown to affect the clinical course and outcome of systemic lupus erythematosus (SLE). Herein, we aimed to define the differences in clinical characteristics, organ damage, and survival between patients with juvenile-onset (jSLE) and adult-onset SLE (aSLE).

Methods.

For the study, 719 patients (76.9%) with aSLE and 216 (23.1%) with jSLE were examined. Comparisons between the groups were made for demographic characteristics, clinical features, auto-antibody profiles, damage, and survival rates.

Results.

These results were significantly more frequent in jSLE: photosensitivity, malar rash, oral ulcers, renal involvement, neuropsychiatric (NP) manifestations, and autoimmune hemolytic anemia (AIHA). Of the autoantibodies, a higher frequency of anti-dsDNA and anticardiolipin IgG and IgM were observed in the jSLE group. A significant proportion of patients with aSLE had anti-Sm positivity and pleuritis. The proportion of patients with jSLE who developed organ damage was comparable to that of patients with aSLE (53% vs 47%) and the mean damage scores were similar in both groups. Renal damage was significantly more frequent in jSLE while musculoskeletal and cardiovascular system damage and diabetes mellitus were more prominent in aSLE. Comparison of survival rates of the 2 groups did not reveal any significant differences.

Conclusion.

We report a higher frequency in the jSLE group of renal involvement, cutaneous symptoms, oral ulcers, NP manifestations, AIHA, and anti-dsDNA positivity. A significant proportion of patients in the jSLE group had damage, most prominently in the renal domain. Our findings might support different genetic/environmental backgrounds for these 2 subgroups.

Interleukin-10 promoter polymorphisms and expression in Thai children with juvenile systemic lupus erythematosus

Interleukin (IL)-10 expression is regulated by its promoter and correlated with the activity of adult-onset lupus (systemic lupus erythematosus (SLE)). As the pathogenesis of adult-onset SLE may differ from SLE with the age at onset <18 years old (juvenile SLE or JSLE), we evaluated polymorphisms at positions −1082A/G, −819T/C and −592A/C of the IL-10 promoter and serum IL-10 levels in 71 patients with JSLE. Disease activity was determined by the SLE disease activity index (SLEDAI). Active SLE was defined by SLEDAI ≥6 and inactive SLE was defined by SLEDAI equal to zero. The mean age was 14.5 ± 2.8 years. Nephritis occurred in 57 patients. In JSLE patients, −592 CC and −819 CC were identified with a higher frequency than in controls with the odds ratio (OR) of 2.75 (95% confidence interval (CI) 1.11–6.81, p = 0.04). GCC increased the susceptibility to nephritis in patients with JSLE (OR 2.16, 95% CI 1.07–4.35, p = 0.03). Serum IL-10 levels were significantly higher in 20 JSLE patients with active disease than in 27 patients with inactive disease and in 15 healthy children ( p < 0.001). In conclusion, IL-10 expression was upregulated in active JSLE. The −819 CC and −592 CC genotypes increased the susceptibility to JSLE and GCC increased the susceptibility to nephritis.

Diagnostic value and clinical laboratory associations of antibodies against recombinant ribosomal P0, P1 and P2 proteins and their native heterocomplex in a Caucasian cohort with systemic lupus erythematosus

Introduction

In this study, we sought to determine the diagnostic value and clinical laboratory associations of autoantibodies against recombinant ribosomal P0, P1 and P2 proteins and their native heterocomplex in systemic lupus erythematosus (SLE).

Methods

Autoantibodies against recombinant ribosomal P proteins (aRibP_R0, aRibP_R1 and aRibP_R2) and antibodies against native ribosomal P heterocomplex (aRibP_NH) were determined in sera from patients with SLE (n = 163), systemic sclerosis (n = 66), Sjögren's syndrome (n = 54), rheumatoid arthritis (n = 90) and healthy donors (n = 100) using enzyme-linked immunosorbent assay. Test results were correlated to medical records, including the American College of Rheumatology criteria, the Systemic Lupus Erythematosus Disease Activity Index 2000, laboratory data and medications of all SLE patients.

Results

Sensitivities of 22.0% for aRibP_R0, 14.9% for aRibP_R2, 14.3% for aRibP_NH and 10.7% for aRibP_R1 were obtained at a specificity of 99%. The assay for aRibP_R0 detection demonstrated the best performance in receiver-operating characteristics analysis, with aRibP_R0 detectable in 10% of anti-Smith antibody and anti-double-stranded DNA-negative sera at a specificity of 100%. ARibP_R0 positivity was associated with lymphocytopenia. ARibP_R1⁺ patients had significantly higher γ-glutamyl transpeptidase (GGT) levels than their aRibP_R1^- counterparts. No specific damage occurred in aRibP⁺ lupus patients compared with a group of age-, sex- and nephritis-matched aRibP^- lupus patients within 3 years.

Conclusions

The determination of antibodies against ribosomal P proteins improves the diagnosis of SLE and should therefore be implemented in upcoming criteria for the diagnosis or classification of SLE. High titers of aRibP_R0 can be associated with lymphocytopenia, and high titers of aRibP_R1 can be associated with elevated GGT levels. So far, there is no evidence for a prognostic value of aRibPs for damage.

Clinical presentations and outcomes of Filipino juvenile systemic lupus erythematosus

OBJECTIVE

Juvenile Systemic Lupus Erythematosus (SLE) varies by location and ethnicity. This study describes the clinical, laboratory profile and outcome of juvenile SLE seen at Philippine General Hospital (PGH) from 2004-2008.

METHOD

Medical charts of all Filipino Juvenile SLE cases admitted at PGH during the 5-year period were reviewed collecting demographic profile, clinical and laboratory manifestations and treatment during disease course.

RESULTS

Seventy-eight cases of juvenile SLE were reviewed. There were 7 boys and 71 girls. The mean age at diagnosis was 14 years (SD 2.7) with a range of 8-18 years. Fever (52.5%) and malar rash (41.0%) were the most common features at disease onset. At the time of diagnosis, the most common features were malar rash (65.3%), renal involvement (62.8%) and photosensitivity (55.1%). Mucocutaneous (92.3%), renal (71.7%) and hematologic (69.2%) involvement were the most common features during the entire course of illness. Infection (34.5%) and neurologic (19.0%) complications were observed most frequently. Corticocosteroid treatment was given in most of the patients in the form of prednisone (97.4%) and concomitant methylprednisolone intravenous pulses (29.4%). Nine patients died during the study period. The overall 5-year mortality rate was 11.5%. Infection (77.0%) was the most frequent cause of death.

CONCLUSION

Malar rash was a common feature at disease onset and at diagnosis among Filipinos with juvenile SLE. Throughout the disease course, renal involvement occurs in 71.7% of patients. Infection was the leading cause of complication and death. The clinical presentations of Filipinos with juvenile SLE were similar to juvenile SLE in other countries.

Epidemiologic, socioeconomic and psychosocial aspects in lupus erythematosus

Epidemiologic, socioeconomic, and psychosocial factors play an important role in health care and handling of patients with the various clinical forms of lupus erythematosus (LE). Patients with LE are mostly young women; adolescents and some ethnic groups are especially prone to a severe course of disease. The unpredictable and fluctuating flares of disease, the need for longterm treatment, and the side effects and damage caused by the disease itself severely reduce quality of life. Problems arise, involving family members, adherence to medical advice and therapy, communication and self management. Socioeconomically, patients are often unable to take regular employment and to pay for health insurance. Stress factors that arise have a negative impact on the course of disease, increasing both fatigue and the basic burden of illness. Healthcare professionals must pay careful attention to all these items, as they attempt to treat flares, minimize drug side effects, provide pain relief, arrange communication and exercise programs along with behavioral and psychosocial interventions in multidisciplinary cooperation, and also involve and support family members.

Overlapping juvenile idiopathic arthritis and systemic lupus erythematosus: a case report

Hereby, we report the case of a 12-year-old girl developing oligoarthritis and progressing into a polyarticular form. Rheumatoid factor was positive, and juvenile idiopathic arthritis (JIA) was diagnosed. After a poor response to DMARDs, an anti-TNF agent (infliximab) was initiated, but to be discontinued due to an allergic reaction. The same complication was observed with the fully human derivative, adalimumab. At the age of 22, the patient presented septicemia with severe anemia and subsequent development of leukopenia, myocarditis with heart failure, and ANA, aSm, aSS-A, aCL positives, and nephrotic syndrome. These new clinical manifestations fulfilled the classification criteria for the diagnosis of systemic lupus erythematosus. Due to the poor therapeutic responses for both diseases, alternative medical options have to be considered, such as targeted therapy with anti-CD20 or interleukin-6 receptor antagonist monoclonal antibodies. This patient may also be a candidate for autologous hemopoietic stem cell transplantation.

Epidemiology and course of disease in childhood uveitis

PURPOSE

To describe the disease characteristics and visual outcome of pediatric uveitis.

DESIGN

Retrospective, longitudinal observation.

PARTICIPANTS

Five hundred twenty-seven pediatric uveitis patients from the National Eye Institute, University of Illinois, Chicago, and Oregon Health Sciences University.

METHODS

Retrospective chart review.

MAIN OUTCOME MEASURES

Demographics, uveitis disease characteristics, complications, treatments, and visual outcomes were determined at baseline and at 1-, 3-, 5-, and 10-year time points.

RESULTS

The patient population was 54% female; 62.4% white, 12.5% black, 2.7% Asian, 2.1% multiracial, and 14.61% Hispanic. Median age at diagnosis was 9.4 years. The leading diagnoses were idiopathic uveitis (28.8%), juvenile idiopathic arthritis-associated uveitis (20.9%), and pars planitis (17.1%). Insidious onset (58%) and persistent duration (75.3%) were most common. Anterior uveitis was predominant (44.6%). Complications were frequent, and cystoid macular edema (odds ratio [OR] 2.94; P = 0.006) and hypotony (OR, 4.54; P = 0.026) had the most significant visual impact. Ocular surgery was performed in 18.9% of patients. The prevalence of legal blindness was 9.23% at baseline, 6.52% at 1 year, 3.17% at 3 years, 15.15% at 5 years, and 7.69% at 10 years. Posterior uveitis and panuveitis had more severe vision loss. Hispanic ethnicity was associated with a higher prevalence of infectious uveitis and vision loss at baseline.

CONCLUSIONS

The rate and spectrum of vision threatening complications of pediatric uveitis are significant. Prospective studies using standard outcome measures and including diverse populations are needed to identify children most at risk.