A case haploinsuffificiency of A20 was initial diagnosed as systemic lupus erythematosus

doi:10.21203/rs.3.rs-3949629/v1

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A case haploinsuffificiency of A20 was initial diagnosed as systemic lupus erythematosus

https://doi.org/10.21203/rs.3.rs-3949629/v1

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Background

Haploinsuffificiency of A20 (HA20) is one of inborn errors of immunity causing severe autoinflammatory and autoimmune disorders.

Case presentation:

Here we reported a case of a 1-year-and-9-month-old boy presented for treatment with pain, swelling and limited mobility in his right ankle. Multiple positive autoantibodies were examined with a history of recurrent oral ulcers during follow-up, and finally diagnosed as HA20 by molecular genetic testing. Clinical symptoms were relieved after treatment.

Conclusion

The clinical heterogeneity of HA20 is significant, the child presented with arthritis, recurrent oral ulcer, positive autoantibodies, mild to moderate anemia, inflammatory markers, and multiple ulcers under colonoscopy, which were similar to systemic lupus erythematosus. Additionally, a new mutation determining a framesetter change of TNFAIP3 gene was detected.

Haploinsuffificiency of A20 (HA20)

TNFAIP3

gene

autoinflammatory disease

systemic lupus erythematosus (SLE)

A20, encoded by the tumor necrosis factor alpha-induced protein 3 (TNFAIP3) gene, has been identified as a negative regulator involved in the TNF-nuclear factor-kB (NF-kB) signaling pathway. Haploinsufficiency of A20 (HA20) was first reported to be generated from heterozygous mutation of TNFAIP3 gene since 2016, mainly characterized with Behcet-like features such as recurrent aphthous stomatitis, genital ulcers, and gastrointestinal symptoms^[1]. Variations in symptoms, disease severity, and response to treatment occurs even among individuals within the same family carrying same mutation.

A 1-year-and-9-month-old boy presented for treatment with pain, swelling, and limitation of motion in his right ankle for 40 days. Six months after birth, the patient underwent recurrent fevers and oral ulcers. During the onset of the disease, levels of C-reactive protein (CRP) and white blood cell (WBC) count were increased. Now the patient was admitted to our hospital for further evaluation and treatment. Physical examination demonstrated two ulcers in the oral cavity. Multiple enlarged lymph nodes were found palpable in the neck and left inguinal region, with a maximum size of 1.0 cm × 1.5 cm and medium mass. The right ankle joint was obviously swollen and the skin temperature was slightly higher, with mobility limitation, and clearly weakened dorsiflexion and plantarflexion.

Laboratory examination: Blood routine examination results showed that WBC count (9.45–12.53) × 10⁹/L, hemoglobin (84–86) g/L, CRP 36.54 mg/L, erythrocyte sedimentation rate (ESR) was 72 mm/h, human leukocyte antigen B27 (HLA B27) was positive, and cytokine levels of IL-2 18.21 pg/ml, IL-5 6.40 pg/ml. The direct anti-human globulin test was positive. Autoantibody series test indicated that ANA 1:320, anti-kinetochore B antibody+, anti-histone antibody+, anti-dsDNA antibody 584.97 IU/ml, anti-cardiolipin IgG (17.98 U/ml), anti-β2 glycoprotein 1 IgG (54.26 RU/mL), anti-β2 glycoprotein 1 antibody IgM (32.61 RU/mL). Other routine laboratory test findings were negative (e.g.urine and stool routines, procalcitonin (PCT), liver function, renal function, rheumatoid factor (RF), antistreptolysin O (ASO), complement, blood culture, joint fluid culture, and antibody analysis (T-SPOT, HSV, HCV, HIV, and syphilis). Bone marrow (BM) cytology indicated anemic BM. Images of brain CT, chest CT and echocardiography showed no obvious abnormalities. MRI showed a small amount of right ankle joint effusion, besides, soft tissue swelling was noted both in the muscle space of the right distal calf and around the right ankle joint.

Anti-infection treatment with cefuroxime was started after admission, but the recovery of joint swelling was poor.

The patient suffered from three clinical manifestations of recurrent oral ulcer, synovitis and hemolytic anemia, which closely aligned with five immunological indicators including ANA positive, anti-dsDNA positive, antiphospholipid antibody positive, anti-β2 glycoprotein antibody 1 positive, and direct anti-human globulin test positive. Therefore, the definite diagnosis of systemic lupus erythematosus (SLE) was clearly established. According to SLEDAI-2000 scores, mucosal ulcer was scored 2, arthritis was scored 4, and anti-dsDNA antibody was scored 2, for a total of 8. The patient was administrated with methotrexate, ibuprofen and prednisone acetate. After treatment, improvement in the patient’s joint swelling was observed.

The age of the disease onset in this child patient was young. Six months after birth, the patient presented with recurrent oral ulcer, and combined now with polyarthritis. In addition, he usually had fever in the past, accompanied by elevated routine blood and CRP level. Autoinflammatory diseases (ADs) with the onset of SLE and BD should be excluded, hence genetic detection of ADs should be improved as soon as possible.

There was a heterozygous mutation in the TNFAIP3 gene, c.1494C > A (p.C498x) (Figs. 1 and 2). As indicated in Fig. 2, the patient’s father carried a heterozygous mutation in this locus, and his mother has normal TNFAIP3 gene sequence, hence HA20 was diagnosed. Moreover, this family self-reduced and ceased medication, and received traditional Chinese medicine treatment. Subsequently, the child patient left lower limb was unable to straighten, significant swelling was observed in the left knee. Therefore, the patient was readmitted for adjusted treatment.

Laboratory examination: Blood routine examination data showed WBC count 10.42 × 10⁹/L, hemoglobin 95 g/L, ESR 40 mm/h. Cytokines level detection results showed that IL-2 was 8.42 pg/mL and IL-6 was 13.93 pg/mL. Antinuclear antibody series test indicated that ANA 1:320, anti-dsDNA antibody IgG 102.71 IU/Ml. Antiphospholipid antibodies test: negative. Gastroscopy diagnosis: chronic superficial gastritis, ileocecal valve ulcer, with multiplicity of colon ulcer (Fig. 3).

The patient consisted of multiorganic involvement which polyarthritis and gastrointestinal ulcers appeared more significantly, so he was given colchicine, mesalazine, thalidomide and infliximab administration. After discharge, the patient continued with these drugs and returned to the hospital on time for infliximab subcutaneous treatment. Oral ulcer of the child patient was cured, and joint swelling was significantly improved. Reexamination of colonoscopy after 3 months indicated ileocecal valve ulcer and colitis were improved.

A20 is a cytosolic protein encoded by TNFAIP3 gene that inhibits nuclear factor-κB (NF-κB) activity and tumor necrosis factor (TNF)-mediated programmed cell death (PCD) ^[2]. The TNFAIP3 gene is located on chromosome 6q23.3, which consists of 9 exons encoding 790 amino acid residues. TNFAIP3 are comprised of two functional domains, ovarian tumor domain (OTU), and zinc finger domain (ZnF). OTU domain is a deubiquitinating enzyme which removes K63-ubiquitinated chain from the target protein ^[3–4]. ZnF domain is an ubiquitination ligase with seven repetitive zinc fingers which ubiquitinates the K48-ubiquitination chain with receptor interacting protein (RIP). The most common mutation forms of TNFAIP3 gene are nonsense and frameshift mutation. Some researchers indicated that HA20 onset in patients with disrupted ZnF domain is much earlier compared to those with disrupted OTU domain. Different to OTU domain, ZnF domain might be more closely related to musculoskeletal disorders ^[5].

Loss-of-function mutation in TNFAIP3 defines a newly described autoinflammatory disease called haploinsufciency of A20 (HA20) ^[6]. The definition of “Haploinsufficient” reveals that one allele is mutated while the other is normally expressed, but it is also recognized that only 50% of the normal level of protein is insufficient to maintain the normal physiological function of cells.

The patient was found carrying the TNFAIP3 gene mutation (c.1494C > A). Searching the Human Gene Mutation Database (HGMD) and other publically available database such as ClinVar, there was no literature report and collection. Moreover, TNFAIP3 single nucleotide polymorphism (SNP) has been revealed associated with juvenile idiopathic arthritis (JIA), inflammatory bowel disease (IBD), SLE, and other autoimmune disorders ^[7–8].

The HA20 is characterized by an early age of disease onset, aggregation of family, inherited in a dominant way. The clinical symptoms of HA20 are remarkably diverse, including oral ulcer, genital ulcer, pseudofolliculitis, erythema nodosa, binocular uveitis, and central nervous system vasculitis. Recurrent fever, polyarthritis, arthritis may even be the first symptom of the HA20 disease. HA20 patients in East Asia presented with recurrent fever more frequently compared to those from other regions, yet less frequently having classical BD symptoms such as skin rashes and genital ulcers ^[9]. In this case, the patient was treated due to arthritis. Recurrent oral ulcer was discovered by the medical history and physical examination, frequently prone to fever with elevated inflammatory indicators. His father had recurrent oral ulcer also.

Data from routine laboratory tests are generally not specific for HA20. Indicators for inflammatory status such as CRP and ESR are increased in the acute phase and returned to normal levels in the interictal period. However, in some of the untreated children, indices of inflammation can be further increased. Enhanced inflammatory signals and increased levels of pro-inflammatory factors (IL-1β, IL-6, TNF-α, IL-17, and IFN-γ) are usually observed in HA20 patients. Evidence indicates that most patients respond well to the treatment with cytokine inhibitors targeting anti-IL-1 and TNF. In some HA20 patients, autoantibodies such as antinuclear antibody and anti-double-stranded DNA antibody could be detected, which is closely related to the involvement of A20 in cellular development and function of B cells ^{[3, 10]}. In this case, results of inflammatory mediators and antibodies were consistent with previously reported findings.

There is no standard treatment protocol for HA20 disease. Currently, treatment for HA20 consists primarily of glucocorticoids, immunosuppressants, and biological agents. For example, sufficient or large doses of glucocorticoids are effective in most HA20 patients, but the adverse reactions and chemoresistance cannot be neglected. Immunosuppressive agents include colchicine, methotrexate, azathioprine, cystatin C, thalidomide, and mycophenolate mofetil, etc. Newly emerging biological agents mainly include TNF-inhibitors such as infliximab and adalimumab, IL-1 receptor antagonists such as anakinra, IL-6 receptor antagonist tocilizumab, JAK inhibitor tofacitinib, and anti-CD-20 mab rituximab, etc. For children with IgG subclass deficiency (IgSD), regular gamma globulin replacement therapy is aimed to reduce the infection ^[11].

To sum up, although HA20 has been revealed linked with many autoinflammatory and autoimmune disorders, the exact treatment and prognosis for this disease remains poorly understood. Herein, gene mutation locus accounting for HA20 was newly discovered and reported in this case. We further presented systematical analysis on one case in detail. This study might provide some clues for the diagnosis and treatment of HA20 in the future.

The clinical heterogeneity of HA20 is significant, mainly manifested as early-onset systemic autoinflammation and autoimmune diseases, including Behcet's syndrome, inflammatory bowel disease, lupus like syndrome, autoimmune lymphoproliferative like diseases, etc. The child presented with arthritis, recurrent oral ulcer, positive autoantibodies, mild to moderate anemia, inflammatory markers, and multiple ulcers under colonoscopy, which were similar to systemic lupus erythematosus. Additionally, a new mutation determining a framesetter change of TNFAIP3 gene was detected.

HA20 Haploinsuffificiency of A20

TNFAIP3 tumor necrosis factor alpha-induced protein 3

NF-kB TNF-nuclear factor-kB

CRP C-reactive protein

WBC white blood cell

HLA B27 human leukocyte antigen B27

PCT procalcitonin

RF rheumatoid factor

ASO antistreptolysin O

BM Bone marrow

SLE systemic lupus erythematosus

ADs Autoinflammatory diseases

OTU ovarian tumor domain

ZnF zinc finger domain

RIP receptor interacting protein

HGMD Human Gene Mutation Database

JIA juvenile idiopathic arthritis

IBD inflammatory bowel disease

Acknowledgements

Not applicable.

Author contributions

LLG wrote the first draft of the manuscript. LLG and XQL contributed equally to this study. Each author listed on the manuscript has seen and approved the submission of this version of the manuscript and takes full responsibility for the manuscript. The author(s) read and approved the final manuscript.

Funding sources

The authors did not receive any external funding for this report.

Data Availability

All data available are included in this article. Further enquiries can be directed to the corresponding author.

Ethics Approval

All the studies were conducted in accordance with the Declaration of Helsinki. The ethics committee of Centro Hospitalar Universitário de São João has granted an exemption from requiring ethics approval to this study. All efforts were made to protect the identity of the patient.

Consent for publication

Written informed consent was obtained from the patient for publication of this case report and accompanying images.

Competing interests

The authors declare no conflicts of interest.

Author details

Department of Immunology and Rheumatology, Children’s Hospital Affiliated to Xi’an Jiaotong University, Xi’an, China

Zhou Q, Wang H, Schwartz DM, Stoffels M, Park YH, Zhang Y, et al. Loss-of Function Mutations in TNFAIP3 Leading to A20 Haploinsuffificiency Cause an Early-Onset Autoinflflammatory Disease. Nat Genet. 2016;48:67–73. 10.1038/ng.3459.
Wertz IE, Newton K, Seshasayee D, Kusam S, Lam C, Zhang J et al. Phosphorylation and linear ubiquitin direct A20 inhibition of inflammation [J].Nature.2015; 528(7582):370–5. 10.1038/nature16165.
Dong X, Liu L, Wang Y, Yang X, Wang W, Lin L, et al. Novel Heterogeneous Mutation of TNFAIP3 in a Chinese Patient with Behçet-Like Phenotype and Persistent EBV Viremia. J Clin Immunol. 2019;39(2):188–94. 10.1007/s10875-019-00604-9.
Hymowitz SG, Wertz IE. A20: from ubiquitin editing to tumour suppression. Nat Rev Cancer. 2010;10:332–41. 10.1038/nrc2775.
Chen Y, Ye Z, Chen L, Qin T, Seidler U, Tian D, et al. Association of Clinical Phenotypes in Haploinsufficiency A20 (HA20) With Disrupted Domains of A20. Front Immunol. 2020;11:574992. 10.3389/fimmu.2020.574992.
Yu MP, Xu XS, Zhou Q, Deuitch N, Lu MP. Haploinsufficiency of A20 (HA20): updates on the genetics, phenotype, pathogenesis and treatment. World J Pediatr. 2020;16(6):575–84. 10.1007/s12519-019-00288-6.
Momtazi G, Lambrecht BN, Naranjo JR, Schock BC. Regulators of A20 (TNFAIP3): new drug-able targets in inflammation. Am J Physiol Lung Cell Mol Physiol. 2019;316(3):L456–6469. 10.1152/ajplung.00335.2018.
MaA MBA. A20: linking a complex regulator of ubiquitylation to immunity and human disease. Nat Rev Immunol. 2012;12(11):774–85. 10.1038/nri3313.
Kadowaki T, Kadowaki S, Ohnishi H. A20 Haploinsufficiency in East Asia. Front Immunol. 2021;12:780689. 10.3389/fimmu.2021.780689.
Huang YY, He TY, Xia Y, Luo Y, Weng RH, Luo SL, et al. Clinical phenotype and immunological features of a patient with A20 haploinsufficiency. Chin J Pediatr. 2020;58(03):218–22. 10.3760/cma.j.issn.0578-1310.2020.03.011.
Wu CW, Sasa G, Salih A, Nicholas S, Vogel TP, Cahill G, et al. Complicated Diagnosis and Treatment of HA20 due to Contiguous Gene Deletions involving 6q23.3. J Clin Immunol. 2021;41(6):1420–3. 10.1007/s10875-021-01048-w.

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A case haploinsuffificiency of A20 was initial diagnosed as systemic lupus erythematosus

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Abstract

Background

Case presentation:

Conclusion

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Background

CASE REPORT

DISCUSSION

Conclusion

Abbreviations

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References

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