Profile of patients with Juvenile Dermatomyositis and Anti-MDA5 autoantibodies.

BACKGROUND: Anti-MDA5 autoantibody-positive dermatomyositis (MDA5-DM) is associated with clinically amyopathic forms and rapidly progressive interstitial lung disease (ILD); however, data in children are limited. In this study, we described our cohort of anti-MDA5-positive juvenile DM (MDA5-JDM) from a tertiary care center in North India. METHODS: We performed a retrospective analysis of children with MDA5-JDM who were diagnosed and followed up at our center and compared them with our anti-MDA5-negative cohort. We also compared the published literature on MDA5-DM with the juvenile cohort. RESULTS: Of 66 children with JDM who underwent testing for MSA, 10(15.5%) had anti-MDA5 positivity. The mean age at onset of clinical manifestations was 8.4 years; male: female ratio was 7:3. Five of nine patients who underwent screening HRCT chest had ILD; one amongst them had a fatal rapidly progressive disease. Children with MDA5-JDM had significantly more arthralgia/arthritis (p = 0.006) and ILD (p = 0.0005) compared to anti-MDA5 negative JDM in our cohort. While MDA5-DM had high rates of Raynaud's phenomenon (p = 0.04) and pulmonary involvement (p = 0.001), juvenile patients had a higher prevalence of constitutional symptoms (p = 0.01), skin manifestations (p = 0.003), arthritis (p = 0.001), and muscle weakness (p = 0.001). CONCLUSIONS: Arthritis and ILD are commonly seen with MDA5-JDM; however, the frequency of ILD and clinically amyopathic forms are less common compared to adult counterparts. IMPACT: The frequency of anti-MDA5 antibodies in a North Indian cohort of JDM is much lower (15.5%) compared to adult studies in dermatomyositis from Southeast Asia (~25%). Incidence of interstitial lung disease (ILD) and arthritis is high in anti-MDA5 autoantibody-positive JDM. Rates of a rapidly progressive form of ILD and clinically amyopathic dermatomyositis are much lower in children compared to adults with anti-MDA5-associated dermatomyositis.

Incidence of Kawasaki disease among children in Chandigarh, India during 2015-2019: a trend analysis.

Background: Only limited information exists regarding the epidemiology of Kawasaki disease (KD) in low-income and middle-income countries. The present study provides the incidence of KD during 2015-2019 in Chandigarh, north India. Our centre follows the largest KD cohort in India. Methods: Children with KD at Chandigarh diagnosed during January 2015-December 2019 were enrolled in the study. Annual incidence rates were determined using decadal growth rates of the National Census 2011. We computed the incidence of KD in children aged <5, and <15 years. We also undertook linear trend analysis using our incidence data from 1994 to 2019. Findings: During 2015-2019, 83 patients (66 males, 17 females) were diagnosed with KD in Chandigarh. Incidence rates during these 5 years were 5.64, 9.25, 9.11, 9.87, and 9.72/100,000 in children aged <5 years, and 2.65, 4.44, 3.86, 5.07, 4.74/100,000 in children aged <15 years. The median age at diagnosis was 48 months (range: 12 days to 15 years). Compared to previous data (2009-2014), there was a 53.1% increase in annual incidence of KD in children aged <5 years, and a 53.7% increase in children aged <15 years. Coronary artery abnormalities during acute phase were noted in 16.9%, and in 7.2% of patients at 6 weeks of follow-up. The trend analysis indicated a monthly rise of 0.002 cases per 100,000 children aged <5 years, and 0.0165 cases per 100,000 children aged <15 years. Interpretation: The incidence of KD has continued to show an upward trend in Chandigarh over the period 2015-2019. This may indicate a true rise in the occurrence of KD or may reflect better disease ascertainment as a result of greater awareness about KD amongst healthcare professionals. Funding: None.

Proteomics approach for biomarker discovery in Kawasaki disease.

INTRODUCTION: Kawasaki disease (KD) is a medium vessel vasculitis mainly affecting children below the age of 5. KD is the leading cause of acquired heart disease in developed countries. Diagnosis of KD is clinical, and there are no pathognomonic laboratory tests to confirm the diagnosis. There is a paucity of studies that have utilized proteomic approach for biomarker discovery in KD. Identification of these biomarkers may be helpful for early and more effective diagnosis and may aid in the treatment of KD. AREA COVERED: The present review focuses on studies that have utilized the proteomic approach in the identification of biomarkers in patients with KD. We have divided these biomarkers into three different categories: the biomarkers used for (a) assessment of risk of KD; (b) assessment of risk of coronary artery aneurysms; and (c) assessment of treatment resistance. EXPERT OPINION: Efforts to improve the clinical and diagnostic evaluation of KD have focused on general markers of inflammation that are not specific for KD. Identification of a proteomic-based biomarker can reliably and specifically differentiate KD from other diseases and could help in the prompt diagnosis. Comprehensive analysis of the serum proteome of patients with KD may be helpful in identifying candidate protein biomarkers.

Markers of Endothelial Dysfunction in Kawasaki Disease: An Update.

Kawasaki disease (KD) is a medium vessel vasculitis that has a special predilection for coronary arteries. Cardiovascular complications include the development of coronary artery abnormalities (CAAs) and myocarditis. Endothelial dysfunction (ED) is now recognized to be a key component in the pathogenesis of KD and is believed to contribute to the development of CAAs. ED has been evaluated by several clinical parameters. However, there is paucity of literature on laboratory markers for ED in KD. The evaluation of ED can be aided by the identification of biomarkers such as oxidative stress markers, circulating cells and their progenitors, angiogenesis factors, cytokines, chemokines, cell-adhesion molecules, and adipokines. If validated in multicentric studies, these biomarkers may be useful for monitoring the disease course of KD. They may also provide a useful predictive marker for the development of premature atherosclerosis that is often a concern during long-term follow-up of KD. This review provides insights into the current understanding of the significance of ED in KD.

Intravenous Immunoglobulin in Kawasaki Disease-Evolution and Pathogenic Mechanisms.

Kawasaki disease (KD) is an acute vasculitis of childhood that affects the medium vessels with a special predilection to the involvement of coronary arteries. The major morbidity of this disease is due to coronary artery aneurysm, which occurs in about 25-30% of untreated cases. For decades now, intravenous immunoglobulin (IVIg) has consistently been shown to reduce the risk of CAAs to less than 5%. However, the mechanism of immunomodulation remains unclear. Several studies on the role of IVIg in the modulation of toll-like receptor pathways, autophagy, and apoptosis of the mononuclear phagocytic system, neutrophil extracellular trap, and dendritic cell modulation suggest a modulatory effect on the innate immune system. Similarly, certain studies have shown its effect on T-cell differentiation, cytokine release, and regulatory T-cell function. In this review, we discuss the potential mechanisms underlying the immunomodulatory actions of IVIg in patients with Kawasaki disease. Furthermore, we provide a summary of the evidence regarding various infusion protocols and dosages utilized in the treatment of KD patients.

Granulomatous inflammation and hypogammaglobulinemia: Clinical conundrum of familial hemophagocytic lymphohistiocytosis type 5.

Familial hemophagocytic lymphohistiocytosis (HLH) is an inherited disorder characterized by systemic hyperinflammation caused by an uncontrolled immune response mediated by T-lymphocytes, natural killer (NK) cells, and macrophages. Most children with familial HLH present within first 2 years of life and can have fatal disease unless hematopoietic stem cell transplant (HSCT) is performed (1). However, few patients may have late presentation and prolonged survival. With increasing awareness and facilities to identify HLH these disorders are being identified beyond infancy (2-4). Clinical and laboratory features are often similar to other primary immune deficiency diseases and pose diagnostic challenges (4-6). We report two patients who presented beyond the first decade of life with HLH, granulomatous inflammation, hypogammaglobulinemia, reduced B cells and were diagnosed to have familial HLH type 5 due to defect in STXBP2 gene.

Juvenile dermatomyositis associated with autoantibodies to small ubiquitin-like modifier activating enzyme: a report of 4 cases from North India and a review of literature.

BACKGROUND: Juvenile dermatomyositis (JDM) is the commonest inflammatory myositis in children. The clinical phenotype is often characterized by the presence of myositis-specific antibodies (MSA). Antibodies to small ubiquitin-like modifier activating enzyme (SAE) are amongst the rarest MSA reported in children. MATERIALS AND METHODS: A review of medical records of all patients diagnosed to have JDM during the period January 1992-April 2022 in our institute was done. Case records of children with JDM who had significant positivity for anti-SAE antibody by myositis immunoblot were analysed in detail. RESULTS: Of the 140 children with JDM, MSA immunoblot was carried out in 53 patients-4 (7.5%) amongst these had significant positivity for anti-SAE antibodies. Median age of onset of symptoms was 5.5 years (range: 5-11 years). Clinical features at presentation included fever, photosensitivity, heliotrope rash, and Gottron papules. Clinically significant proximal muscle weakness was noted in 3/4 patients; 1 had no discernible weakness but had radiological evidence of myositis. None of the 4 patients had evidence of interstitial lung disease or calcinosis. All patients were treated with intravenous pulse methylprednisolone: subcutaneous weekly methotrexate and hydroxychloroquine. One patient received mycophenolate mofetil because of a relapse of muscle disease, while none received cyclophosphamide or biologics. Median follow-up duration was 21.5 months (range: 6-39 months). CONCLUSION: Anti-SAE antibodies were found in 4/53 (7.5%) of North Indian children with JDM. All 4 patients had predominant cutaneous manifestations followed by muscle disease. Response to treatment was brisk and sustained. None had developed calcinosis in the follow-up. KEY MESSAGES: 1. We report high prevalence of anti-SAE antibody positivity (7.5%) in North Indian cohort of JDM. 2. Cutaneous disease precedes muscle weakness in children with anti-SAE positive JDM. 3. No evidence of interstitial lung disease/calcinosis was seen in these children.

Association of single nucleotide polymorphism rs113420705 of CASP3 in children with Kawasaki disease from North India.

Background: Kawasaki disease is a pediatric, systemic, vasculitic disorder. Its exact etiology is still unknown. Genetic polymorphisms are being investigated as susceptibility factor for this disorder. These are likely to vary among different populations. Aim: To investigate the association of single nucleotide polymorphism (SNP) rs113420705 of CASP3 in Kawasaki disease (KD) from North India. Settings and Design: Observational, case-control study. Methods: Polymerase chain reaction and bidirectional Sanger sequencing was used for determining genotypes of SNP rs113420705 in 45 cases of KD and 50 healthy age- and sex-matched controls. Allele and genotype frequencies were assessed and compared between the groups. Results: Among 45 cases, 32 had TT (71.1%), 13 had CT (28.9%) and none had CC genotype of SNP rs113420705. No significant differences in allele, genotype, or carrier frequencies of rs113420705 were found between the two groups. A comparison was also made between subgroups of KD with coronary abnormality (7 children; 15.5%) and KD with normal coronaries (38 children; 84.4%). The C allele was significantly overexpressed in KD with coronary abnormality group (P = 0.005). However, no difference was noted in the genotype frequencies. Conclusion: CT genotype of rs113420705 of CASP3 showed a trend to significance with the occurrence of KD in children in North India. However, we could not establish any association between minor allele C and susceptibility to KD. C allele appeared to be over expressed in children with KD with coronary abnormalities. Larger studies will help us to reach conclusive evidence applicable to all ethnicities.

Blau syndrome: Lessons learned in a tertiary care centre at Chandigarh, North India.

Objectives: Blau syndrome (BS) is a rare autoinflammatory disease characterized by arthritis, dermatitis, and granulomatous uveitis in early childhood. The study presents the clinical experience of patients with BS at a tertiary care centre in Chandigarh, North India. Methods: Analysis of the clinical profile of patients of BS with NOD2 gene mutations under follow-up was carried out. Results: Diagnosis of BS was genetically confirmed in 11 patients (10 children and one adult; six male and five female patients) from 10 families. The median age of onset of symptoms was 12 months (range, 4 months-4 years), while the age at diagnosis ranged from 2.3 to 26 years. The classic triad of arthritis, dermatitis, and uveitis was present in 6/11 (54.5%) patients. The frequency of arthritis, dermatitis, and uveitis was 100%, 81.8%, and 72.7%, respectively. The median age at diagnosis of ocular symptoms was 4 years (range, 2-26 years). Family history was noted in six families. Renal involvement was observed in two children. All patients in our cohort had the R334W variant in NOD2 gene. An asymptomatic carrier sibling with R334W mutation was identified in one family. Methotrexate was used as a first-line agent in all children. Adalimumab, which was commenced in five patients with uveitis, resulted in significant improvement in four patients. The total follow-up duration of the present cohort is 1,063.8 patient-months. Conclusions: The possibility of BS should always be considered in patients with arthritis and early ocular involvement. Uveitis is often progressive and refractory to currently available therapies. Systemic involvement appears to remain a significant cause of morbidity and mortality.

Features of Hemophagocytic Lymphohistiocytosis in Infants With Severe Combined Immunodeficiency: Our Experience From Chandigarh, North India.

Background: Hemophagocytic lymphohistiocytosis (HLH) is characterized by uncontrolled and excessive inflammation leading to high mortality. Aetiology of HLH can be primarily due to genetic causes or secondarily due to infections or rheumatological illness. However, rarely T-cell deficiencies like severe combined immunodeficiency (SCID) can develop HLH. Objective: To describe clinical and laboratory features of SCID cases who developed HLH. Methods: We collected clinical, laboratory, and molecular details of patients with SCID who developed HLH at our center at Chandigarh, North India. Results: Of the 94 cases with SCID, 6 were noted to have developed HLH-like manifestations. Male-female ratio was 5:1. Median (inter-quartile range) age of onset of clinical symptoms was 4.25 months (2-5 months). Median (inter-quartile range) delay in diagnosis was 1 month (1-3.5 months). Family history of deaths was seen in 4 cases. Molecular defects in IL2RG were seen in 5 out of 6 cases. Documented infections include disseminated bacillus calmette-guerin (BCG) infection (n=2), blood stream infections (n=3) with Staphylococcal aureus (n=1), Klebsiella pneumonia (n=1), and Pseudomonas aeruginosa (n=1), pneumonia (influenza H1N1 strain, and K. pneumoniae (n=1). Conclusion: Children with SCID can present with HLH-like manifestations secondary to fulminant infections. A high index of suspicion of SCID is needed in infants who present with HLH who have an associated infection or a suggestive family history. Occurrence of HLH-like manifestations in SCID suggests that T-lymphocytes may not have a significant role in immunopathogenesis of HLH.

Deficiency of Human Adenosine Deaminase Type 2 - A Diagnostic Conundrum for the Hematologist.

Deficiency of adenosine deaminase type 2 (DADA2) was first described in 2014 as a monogenic cause of polyartertitis nodosa (PAN), early onset lacunar stroke and livedo reticularis. The clinical phenotype of DADA2 is, however, very broad and may involve several organ systems. Apart from vasculitis, children may present with i) Hematological manifestations (ii) Lymphoproliferation and iii) Immunodeficiencies. Patients with DADA2 can have variable patterns of cytopenias and bone marrow failure syndromes. Patients with DADA2 who have predominant haematological manifestations are associated with ADA2 gene variants that result in minimal or no residual ADA2 activity. Lymphoproliferation in patients with DADA2 may range from benign lymphoid hyperplasia to lymphoreticular malignancies. Patients may present with generalized lymphadenopathy, splenomegaly, autoimmune lymphoproliferative syndrome (ALPS) like phenotype, Hodgkin lymphoma, T-cell large granular lymphocytic infiltration of bone marrow and multicentric Castleman disease. Immunodeficiencies associated with DADA are usually mild. Affected patients have variable hypogammaglobulinemia, decrease in B cells, low natural killer cells, common variable immunodeficiency and rarely T cell immunodeficiency. To conclude, DADA2 has an extremely variable phenotype and needs to be considered as a differential diagnosis in diverse clinical conditions. In this review, we describe the evolving clinical phenotypes of DADA2 with a special focus on haematological and immunological manifestations.

Association of SNP (rs1042579) in thrombomodulin gene and plasma thrombomodulin level in North Indian children with Kawasaki disease.

BACKGROUND: Kawasaki disease (KD) is the commonest systemic vasculitis in children. It predisposes to development of coronary artery abnormalities (CAAs). Thrombomodulin (THBD) gene polymorphism rs1042579 is associated with high risk of cerebrovascular diseases. However, association of THBD polymorphism (rs1042579) and plasma thrombomodulin (TM) levels with susceptibility to KD and CAAs remains unclear. METHODS AND RESULTS: Polymorphism in THBD gene (rs1042579) was analysed in 50 KD patients and 50 age, gender and ethnicity matched controls using Sanger sequencing. Plasma TM levels were measured by ELISA. RESULTS: Mean plasma TM level (± SD) in KD patients was 2549.41 (± 853.18) pg/ml and in controls was 2298.03 (± 869.14) pg/ml; p = 0.042. Mean plasma TM levels in CC genotype was 2299.98 (± 834.88) pg/ml and in CT/TT genotype was 2837.96 (± 857.14) pg/ml; p = 0.005. Genotyping data did not reveal significant differences in patients with KD as compared to controls (p = 0.25), and in KD patients with and without CAAs (p = 0.407). Odds of finding T allele in cases were 2.07 times greater than in controls (p = 0.093). CONCLUSIONS: This is the first study from India, and second in the world, that investigates association of THBD gene polymorphism with KD. This is also the first study to assess plasma TM levels in KD patients. Our data show that plasma TM levels were significantly higher in KD patients with CT/TT genotypes. Further, the polymorphism rs1042579 at exon 1 of THBD gene was found to be more common in KD patients than in controls although the difference was not statistically significant.

Exploration of Potential Biomarker Genes and Pathways in Kawasaki Disease: An Integrated in-Silico Approach.

Kawasaki disease (KD) is a common childhood systemic vasculitis with a special predilection for coronary arteries. Even after more than five decades of the initial description of the disease, the etiology of KD remains an enigma. This transcriptome data re-analysis study aimed to elucidate the underlying pathogenesis of KD using a bioinformatic approach to identify differentially expressed genes (DEGs) to delineate common pathways involved in KD. Array datasets from the Gene Expression Omnibus database were extracted and subjected to comparative meta-analysis for the identification of prominent DEGs. Fifteen hub genes with high connectivity were selected from these DEGs (IL1B, ITGAM, TLR2, CXCL8, SPI1, S100A12, MMP9, PRF1, TLR8, TREM1, CD44, UBB, FCER1G, IL7R, and FCGR1A). Of these 15 genes, five genes (CXCL8, FCGR1A, IL1B, TLR2, and TLR8) were found to be involved in neutrophil degranulation. To gain further insight into the molecular mechanism, a protein-protein network was established. Significantly enriched pathways based on the above-mentioned genes were mainly centered on biological regulation and signaling events. In addition, the pathway analysis also indicated that the majority of the DEGs in KD were enriched in systemic lupus erythematosus, suggesting a strong interplay between immunological and genetic factors in the pathogenesis of KD. These findings could significantly aid in identifying therapeutic targets and understanding KD biosignatures to design a biomarker panel for early diagnosis and severity of the disease.

Association of ITPKC gene polymorphisms rs28493229 and rs2290692 in North Indian children with Kawasaki disease.

BACKGROUND: Single-nucleotide polymorphisms (SNPs) of several genes are linked to the etiopathogenesis of Kawasaki disease (KD). Association of SNPs of inositol 1,4,5-triphosphate-3-kinase C (ITPKC) gene with susceptibility to KD and coronary artery lesions (CALs) has been observed in children of certain ethnicities, but not from others. The present study was planned to explore this genetic association in the North Indian cohort. METHODS: Fifty children with KD and 50 age- and sex-matched controls were studied for two SNPs (rs28493229 and rs2290692) of the ITPKC gene using polymerase chain reaction and restriction fragment length polymorphism. Findings were confirmed by Sanger sequencing. A meta-analysis was also carried out for GG and CC genotypes of the SNPs. RESULTS: There was significant association between KD susceptibility and CG + GG genotype of rs2290692 (p = 0.015, odds ratio = 4.1, 95% confidence interval = 1.38-13.83). None of the single alleles or genotypes of the SNPs of ITPKC were, however, significantly associated with KD susceptibility. A meta-analysis also did not show any significant association of these SNPs to KD susceptibility. CONCLUSIONS: Our findings suggest that ITPKC gene SNPs (rs28493229 and rs2290692) did not have a significant association with susceptibility to KD in children from North India. Larger multicentric studies incorporating different ethnicities are required to understand the genetic basis of KD. IMPACT: While SNP rs28493229 of the ITPKC gene is not found to be associated with susceptibility to KD, the combined genotype of SNP rs2290692 is shown to be associated. Impact of ITPKC gene SNP on KD is different across different races and ethnicities. We could find an association of the combined genotype of rs2290692 with it in the Indian population. This study highlights that phenotype and genotypic association of KD varies with ethnicities. Larger multicentric studies are required to reach a conclusion regarding the genetic association of KD.

What Lies Ahead for Young Hearts in the 21st Century - Is It Double Trouble of Acute Rheumatic Fever and Kawasaki Disease in Developing Countries?

Rheumatic heart disease (RHD), the principal long-term sequel of acute rheumatic fever (ARF), has been a major contributor to cardiac-related mortality in general population, especially in developing countries. With improvement in health and sanitation facilities across the globe, there has been almost a 50% reduction in mortality rate due to RHD over the last 25 years. However, recent estimates suggest that RHD still results in more than 300,000 deaths annually. In India alone, more than 100,000 deaths occur due to RHD every year (Watkins DA et al., N Engl J Med, 2017). Children and adolescents (aged below 15 years) constitute at least one-fourth of the total population in India. Besides, ARF is, for the most part, a pediatric disorder. The pediatric population, therefore, requires special consideration in developing countries to reduce the burden of RHD. In the developed world, Kawasaki disease (KD) has emerged as the most important cause of acquired heart disease in children. Mirroring global trends over the past two decades, India also has witnessed a surge in the number of cases of KD. Similarly, many regions across the globe classified as "high-risk" for ARF have witnessed an increasing trend in the incidence of KD. This translates to a double challenge faced by pediatric health care providers in improving cardiac outcomes of children affected with ARF or KD. We highlight this predicament by reviewing the incidence trends of ARF and KD over the last 50 years in ARF "high-risk" regions.

Spectrum of Systemic Auto-Inflammatory Diseases in India: A Multi-Centric Experience.

Background: Systemic autoinflammatory diseases (SAID) are rare inherited disorders involving genes regulating innate immune signaling and are characterized by periodic or chronic multi-systemic inflammation. Objective: To describe spectrum of clinical, immunological, molecular features, and outcomes of patients with SAID in India. Methods: Request to share data was sent to multiple centers in India that are involved in care and management of patients with Inborn Errors of Immunity. Six centers provided requisite data that were compiled and analyzed. Results: Data on 107 patients with SAID were collated-of these, 29 patients were excluded due to unavailability of complete information. Twelve patients (15%) had type 1 interferonopathies, 21 (26%) had diseases affecting inflammasomes, 30 patients (41%) had non-inflammasome related conditions and 1five patients (19%) had Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis (PFAPA). Type1 interferonopathies identified in the cohort included patients with Deficiency of Adenosine Deaminase 2 (DADA2) (six patients; five families); STING-associated vasculopathy infantile-onset (SAVI) (three patients, one family); Spondyloenchondro-dysplasia with Immune Dysregulation (SPENCD) (two patients). Diseases affecting inflammasomes include Mevalonate Kinase Deficiency (eight patients); Cryopyrin-Associated Periodic Syndromes (CAPS) (seven patients); NLR Family, Pyrin domain-containing 12 (NLRP12) (two patients); Familial Mediterranean fever (FMF) (two patients); Autoinflammation and PLCG2-associated antibody deficiency and immune dysregulation (APLAID) (two patients). TNF receptor-associated periodic syndrome (TRAPS) (three patients); A20 haploinsufficiency (four patients); Deficiency of Interleukin 1 Receptor Antagonist (DIRA) (two patients) were categorized as non-inflammasome related conditions. There were significant delays in diagnosis Corticosteroids and other immunosuppressive agents were used for treatment as anti-IL-1 drugs and other biological agents were and still are not available in India. Eight (16.3%) patients had so far succumbed to their illness. Conclusions: This is the first nationwide cohort of patients with SAID from India. Clinical manifestations were diverse. Overlapping of clinical features with other relatively common rheumatological disorders often resulted in delays in diagnosis. More nationwide efforts are needed to enhance awareness of SAID among health care professionals and there is an urgent need to make targeted immunotherapies universally available.

Syndrome of progressive deforming non-inflammatory arthritis of childhood: two patients of camptodactyly-arthropathy-coxa vara-pericarditis syndrome.

Camptodactyly-arthropathy-coxa vara-pericarditis (CACP) syndrome is a rare familial arthropathy of childhood, commonly misdiagnosed as juvenile idiopathic arthritis. It is characterized by non-inflammatory arthropathy, coxa vara deformity, and sterile pericarditis. We describe two children with CACP syndrome who were referred to the rheumatology clinic for the suspicion of inflammatory arthritis. A literature search was carried out using PubMed/ Medline and Embase databases. English language reports of mutation-proven cases of CACP syndrome reported until 31 March 2020 were retrieved and analysed. Both the children had a delay in diagnosis (age at diagnosis- 12 and 13 years, respectively) and had received immunomodulatory therapy for suspected inflammatory arthritis. Presence of symmetrical arthropathy of large joints, camptodactyly, and normal inflammatory parameters are clues that indicated CACP syndrome. One child with a novel variant in PRG4 also had associated mitral valve prolapse and regurgitation. Both had severe constrictive pericarditis requiring pericardiectomy. On literature review, a total of 98 mutation-proven cases of CACP syndrome have been reported till date. Arthropathy in CACP syndrome mainly involves knees, wrists, ankles, and hips. Pericarditis is usually mild, however, can present rarely with severe symptoms requiring surgical intervention. CACP syndrome can closely mimic inflammatory arthritis and early clinical recognition is important to avoid misdiagnosis. Molecular confirmation is essential for early diagnosis and future genetic counselling for affected families.