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Kawasaki disease (KD) has replaced acute rheumatic fever as the most common cause of acquired heart disease in children in the developed world and is increasingly being recognized from several developing countries. It is a systemic vasculitis with a predilection for coronary arteries. The diagnosis is based on a constellation of clinical findings that appear in a temporal sequence. Quite understandably, this can become a problem in situations wherein the clinical features are not typical. In such situations, it can be very difficult, if not impossible, to arrive at a diagnosis. Several biomarkers have been recognized in children with acute KD but none of these has reasonably high sensitivity and specificity in predicting the course of the illness. A line up of inflammatory, proteomic, gene expression and micro-RNA based biomarkers has been studied in association with KD. The commonly used inflammatory markers e.g. erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and total leucocyte counts (TLC) lack specificity for KD. Proteomic studies are based on the identification of specific proteins in serum, plasma and urine by gel electrophoresis. A host of genetic studies have identified genes associated with KD and some of these genes can predict the course and coronary outcomes in the affected individuals. Most of these tests are in the early stages of their development and some of these can predict the course, propensity to develop coronary artery sequelae, intravenous immunoglobulin (IVIg) resistance and the severity of the illness in a patient. Development of clinical criteria based on these tests will improve our diagnostic acumen and aid in early identification and prevention of cardiovascular complications.

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BackgroundSevere Combined Immune Deficiency (SCID) is an inherited defect in lymphocyte development and function that results in life-threatening opportunistic infections in early infancy. Data on SCID from developing countries are scarce.ObjectiveTo describe clinical and laboratory features of SCID diagnosed at immunology centers across India.MethodsA detailed case proforma in an Excel format was prepared by one of the authors (PV) and was sent to centers in India that care for patients with primary immunodeficiency diseases. We collated clinical, laboratory, and molecular details of patients with clinical profile suggestive of SCID and their outcomes. Twelve (12) centers provided necessary details which were then compiled and analyzed. Diagnosis of SCID/combined immune deficiency (CID) was based on 2018 European Society for Immunodeficiencies working definition for SCID.ResultsWe obtained data on 277 children; 254 were categorized as SCID and 23 as CID. Male-female ratio was 196:81. Median (inter-quartile range) age of onset of clinical symptoms and diagnosis was 2.5 months (1, 5) and 5 months (3.5, 8), respectively. Molecular diagnosis was obtained in 162 patients - IL2RG (36), RAG1 (26), ADA (19), RAG2 (17), JAK3 (15), DCLRE1C (13), IL7RA (9), PNP (3), RFXAP (3), CIITA (2), RFXANK (2), NHEJ1 (2), CD3E (2), CD3D (2), RFX5 (2), ZAP70 (2), STK4 (1), CORO1A (1), STIM1 (1), PRKDC (1), AK2 (1), DOCK2 (1), and SP100 (1). Only 23 children (8.3%) received hematopoietic stem cell transplantation (HSCT). Of these, 11 are doing well post-HSCT. Mortality was recorded in 210 children (75.8%).ConclusionWe document an exponential rise in number of cases diagnosed to have SCID over the last 10 years, probably as a result of increasing awareness and improvement in diagnostic facilities at various centers in India. We suspect that these numbers are just the tip of the iceberg. Majority of patients with SCID in India are probably not being recognized and diagnosed at present. Newborn screening for SCID is the need of the hour. Easy access to pediatric HSCT services would ensure that these patients are offered HSCT at an early age.

Inborn errors of immunity usually not only result in immunodeficiency but may also manifest as immune dysregulation in the form of autoinflammation, autoimmunity, or sometimes malignancy. One of the most recently discovered monogenic disorder of immune dysregulation is COPA syndrome. COPA syndrome is an inherited autoimmune disorder caused by mutations in COPA gene. COPA gene encodes for α subunit of the COP1 protein, which is involved in the reverse vesicular protein transport from Golgi apparatus to the endoplasmic reticulum (ER). The inheritance pattern of COPA syndrome is autosomal dominant, and the patients typically present with interstitial lung disease with pulmonary hemorrhage and subsequently develop arthritis. Immunological features involve autoantibody formation, elevated expression of IL-1β and IL-6, and increase in the number of Th17 cells. Molecular pathophysiology of COPA syndrome is not clearly understood. However, it is known that accumulation of unfolded proteins in ER leads to ER stress, which is an indirect result of aberrant vesicular transport of proteins from Golgi apparatus to ER and defective cellular autophagy. ER stress induces inflammation and is responsible for pathogenesis of a large number of chronic inflammatory diseases. Unfolded protein response process responds to improperly folded proteins and defends against stress in ER to ensure the fidelity of the protein folding. It maintains the expression of stress-response genes and causes initiation of inflammatory signaling pathways essential for the innate immunity. Mutation in COPA gene associated with defective protein sorting to ER has unearthed a new primary immunodeficiency disease with a unique clinical phenotype. This review highlights the clinical and molecular aspects of COPA syndrome.