Infections in Disorders of Immune Regulation.

Primary immune regulatory disorders (PIRDs) constitute a spectrum of inborn errors of immunity (IEIs) that are primarily characterized by autoimmunity, lymphoproliferation, atopy, and malignancy. In PIRDs, infections are infrequent compared to other IEIs. While susceptibility to infection primarily stems from antibody deficiency, it is sometimes associated with additional innate immune and T or NK cell defects. The use of immunotherapy and chemotherapy further complicates the immune landscape, increasing the risk of diverse infections. Recurrent sinopulmonary infections, particularly bacterial infections such as those associated with staphylococcal and streptococcal organisms, are the most reported infectious manifestations. Predisposition to viral infections, especially Epstein-Barr virus (EBV)-inducing lymphoproliferation and malignancy, is also seen. Notably, mycobacterial and invasive fungal infections are rarely documented in these disorders. Knowledge about the spectrum of infections in these disorders would prevent diagnostic delays and prevent organ damage. This review delves into the infection profile specific to autoimmune lymphoproliferative syndrome (ALPS), Tregopathies, and syndromes with autoimmunity within the broader context of PIRD. Despite the critical importance of understanding the infectious aspects of these disorders, there remains a scarcity of comprehensive reports on this subject.

Wiskott-Aldrich syndrome protein expression in female WAS carriers: A flow cytometry study from North India.

INTRODUCTION: Wiskott-Aldrich syndrome (WAS) is a rare X-linked inborn error of immunity characterized by microthrombocytopenia, infections, eczema, and increased predisposition to develop autoimmunity and malignancy. Flow cytometric assay for determining WAS protein (WASp) is a rapid and cost-effective tool for detecting patients. However, very few studies described WASp expression in female carriers. Most WAS carriers are clinically asymptomatic. Active screening of female family members helps identify female carriers, distinguish de novo mutations, and to select appropriate donor prior to curative stem cell transplantation. This study was undertaken to evaluate the diagnostic capability of flow cytometry-based WASp expression in peripheral blood cells to identify carriers and compare WASp expression in different blood cell lineages. PATIENTS AND METHODS: Female patients, heterozygous for WAS gene, were enrolled in this study conducted at Pediatric Allergy Immunology Unit, Advanced Pediatric Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India. Flow cytometric assessment of WASp expression in lymphocytes, monocytes, and neutrophils was carried out and compared with healthy control and affected patients. The results were expressed in delta (Δ) median fluorescence intensity (MFI) as well as stain index (SI), which is the ratio of ΔMFI of patient and ΔMFI of control. RESULTS: Thirteen mothers and two sisters of genetically confirmed WAS patients were enrolled in the study. All enrolled females were clinically asymptomatic and did not have microthrombocytopenia. Low WASp expression (SI < 1) was seen in lymphocytes and monocytes in 10 (66.6%) carriers. Females with variants in proximal exons (exons 1 and 2) were found to have lesser expression than those with distal (exons 3-12) variants. CONCLUSION: Flow cytometry is a rapid, easily available, cost-effective tool for WASp estimation. Lymphocytes followed by monocytes are the best cell lineages for WASp estimation in carrier females. However, genetic testing remains the gold standard, as carrier females with variants in distal exons may have normal WASp expression.

X-Linked Lymphoproliferative Syndrome: A Spectrum of Clinical and Immunological Profile and Novel Pathogenic Variants from Chandigarh, India.

INTRODUCTION: X-linked lymphoproliferative syndrome (XLP) is a rare primary immune deficiency. Two types of XLP have been described: XLP-1 and XLP-2. METHODS: We found 7 patients with XLP (3 had XLP-1 and 4 had XLP-2) after reviewing the data from Pediatric Immunodeficiency Clinic from 1997 to 2021. RESULTS: Mean age at diagnosis was 3.8 years, and mean delay in diagnosis was 2.6 years. Five patients had recurrent episodes of infections. Four patients developed at least one episode of hemophagocytic lymphohistiocytosis (HLH) (2 with XLP-1 and 2 with XLP-2). Of these, 2 had recurrent HLH (both with XLP-2). Epstein-Barr virus (EBV) infection was detected in 2 (1 with XLP-1 and 1 with XLP-2). Both these patients had HLH. One child with XLP-2 had inflammatory bowel disease. Hypogammaglobulinemia was seen in 3 (2 with XLP-1 and 1 with XLP-2). Genetic analysis showed previously reported variants in 5, while 2 had novel variants (one in exon 7 of XIAP gene [c.1370dup p.Asn457Lysfs Ter16] and other had splice site variant in intron 1 of SH2D1A gene [c.138-2_138-1insG]). Episodes of HLH were managed with intravenous immunoglobulin (IVIg), methylprednisolone, oral prednisolone, cyclosporine, and rituximab. Inflammatory bowel disease was managed using oral prednisolone and azathioprine. One patient underwent haploidentical hematopoietic stem cell transplantation. One child with XLP-2 and WAS died because of fulminant pneumonia. DISCUSSION/CONCLUSIONS: XLP should be considered as a strong possibility in any patient with features of HLH, repeated infections with hypogammaglobulinemia, persistent EBV infection, and early-onset IBD.

Clinical, immunological and molecular profiles of DOCK8 deficiency in six patients from a tertiary care centre in North India.

BACKGROUND: Dedicator of cytokinesis protein 8 (DOCK8) deficiency is an autosomal recessive form of combined immunodeficiency. This rare disorder is characterized by an increased predisposition to allergy, autoimmunity and malignancies. OBJECTIVES: To analyse clinical, immunological and molecular profiles of patients with DOCK8 deficiency. METHODS: Clinic records of all patients attending the primary immunodeficiency clinic from 2018 to 2021 were reviewed. Six patients from five families were found to have DOCK8 deficiency. RESULTS: Median age at diagnosis was 7.5 years (range 2-13), with a male/female ratio of 5 : 1. Among the six patients, recurrent eczematous skin lesions were the predominant cutaneous manifestation, present in five patients (83%). Warts and molluscum contagiosum were evident in two patients (33%) and one patient (16%), respectively. Two patients had recalcitrant prurigo nodularis lesions and two had epidermodysplasia verruciformis-like lesions. Food allergies and asthma were reported by one patient each. Of the six patients, recurrent sinopulmonary infections were detected in five (83%). Epstein-Barr virus-driven non-Hodgkin lymphoma with liver metastases was the only case of malignancy, in a 4-year-old boy. IgE was elevated in all patients. Lymphopenia and eosinophilia were observed in three patients (50%) and five patients (83.3%), respectively. Genetic analysis showed DOCK8 pathogenic variants in all patients: homozygous deletion mutations in two patients, compound heterozygous deletion mutations in one, and homozygous nonsense mutations in two. A novel pathogenic homozygous missense variant in the DOCK8 gene was identified in one patient. CONCLUSIONS: DOCK8 deficiency should be considered as a possibility in any patient with early onset eczema, cutaneous viral infections and increased predisposition to allergy, autoimmunity and malignancy.

Tuberculosis and Bacillus Calmette-Guérin Disease in Patients with Chronic Granulomatous Disease: an Experience from a Tertiary Care Center in North India.

Chronic granulomatous disease (CGD) is a phagocytic defect characterized by recurrent bacterial and fungal infections. We report clinical profile of patients with CGD and mycobacterial infections in a cohort from North India. A review of clinical and laboratory records was carried out for patients with CGD registered at our center between 1990 and 2021. Of the 99 patients with CGD, 22 had mycobacterial infections-Mycobacterium tuberculosis and M. bovis-BCG in 11 each. Among the children with M. bovis-BCG infection, 6 had localized and 5 had disseminated BCG disease. Median age at onset of symptoms and diagnosis of BCG disease was 5 months and 15 months, respectively. While disseminated forms of BCG were noted only in CYBB defect, none of the patients with NCF1 defect developed complications due to BCG vaccine. A recurring radiological feature was left axillary lymph node calcification, which was present in around 50% of CGD patients with BCG infections. Of 11 patients with tuberculosis, pulmonary, pleuro-pulmonary, abdominal, and disseminated forms were present in 6, 1, 2, and 2, respectively. Median age at onset of symptoms and diagnosis of tuberculosis was 129 months and 130 months, respectively. Molecular defects were identified in CYBB (5), NCF1 (4), and CYBA (1). Incidence of tuberculosis and BCG-related complications in patients with CGD is higher than the normal population. Screening for CGD is warranted in any patient with adverse reactions to BCG vaccination, calcification of left axillary lymph node, and persistent, recurrent or disseminated forms of tuberculosis.

Occurrence of Kawasaki disease and neoplasms in temporal proximity-single-center experience and systematic review of literature.

Various factors (e.g., infections) have been postulated to trigger Kawasaki disease (KD) in genetically predisposed individuals. Whether neoplasms can trigger KD is largely unknown due to paucity of data. Herein, we provide a detailed account of KD occurring in temporal proximity (within 6 months) to neoplasms ('neoplasm-KD'). Patients with 'neoplasm-KD' diagnosed/treated at our center from January 1994 to May 2021 were included. Additionally, we performed a systematic literature review (as per PRISMA 2020 guidelines) utilizing PubMed, Web of Science and Scopus databases to retrieve details of all patients with 'neoplasm-KD' reported till June 2021. Patients with multisystem inflammatory syndrome in children were excluded. As all reports pertained to case description(s), risk of bias assessment was not performed. The details of patients with 'neoplasm-KD' were analyzed using SPSS software. Primary and secondary outcomes were occurrence of coronary artery abnormalities (CAAs) and clinical characteristics of 'neoplasm-KD', respectively. A total of 25 patients (data from 18 reports) were included in the 'neoplasm-KD' dataset. The most frequently diagnosed neoplasm was acute lymphoblastic leukemia followed by neuroblastoma and acute myeloblastic leukemia. Overall, CAAs were noted in 48% of patients. Interval between diagnoses of KD and neoplasm was shorter in patients with CAAs as compared to patients with normal coronary arteries (p-value = 0.03). Besides providing a comprehensive description of 'neoplasm-KD', this study raises a possibility that neoplasms might trigger KD. Also, 'neoplasm-KD' may be associated with a higher risk of development of CAAs. However, the small size of 'neoplasm-KD' dataset precludes definitive conclusions regarding this association. Funding: nil. Registration: PROSPERO (CRD42021270458).

This study is the first exhaustive description of cancers and Kawasaki disease (KD) occurring in close temporal proximity. Nearly half of these patients develop coronary artery abnormalities. In KD, persistent lymphadenopathy, enlargement of liver/spleen and development of low blood cell counts should trigger evaluation for cancer. Our study also raises a possibility that cancers might occasionally trigger KD.

A Well-Curated Cost-Effective Next-Generation Sequencing Panel Identifies a Diverse Landscape of Pathogenic and Novel Germline Variants in a Bone Marrow Failure Cohort in a Resource-Constraint Setting.

The current study is a 4-year experience in diagnosis and screening of inherited and immune bone marrow failure cases using a targeted sequencing panel. A total of 171 cases underwent targeted next-generation sequencing and were categorized as suspected inherited bone marrow failure syndrome (IBMFS) group (106; 62%) and immune/idiopathic aplastic anemia (IAA) group (65; 38%) based on clinical and laboratory criteria. A total of 110 (64%) were pediatric (aged 0 to 12 years) patients and 61 (36%) were adolescent and adult (aged 13 to 47 years) patients. In suspected IBMFS group, 47 (44%), and in IAA group, 8 (12%) revealed a likely germline pathogenic variation. Whole-exome sequencing performed in 15 of 59 suspected IBMFS group cases was negative on targeted panel, and revealed a clinically important variation in 3 (20%) cases. A total of 11 novel variants were identified. The targeted panel helped establish a diagnosis in 44% (27/61) of unclassified bone marrow failure syndrome cases and led to amendment of clinical diagnosis in 5 (4.7%) cases. Overall, diagnostic yield of this well-curated small panel was comparable to Western studies with larger gene panels. Moreover, this was achievable at a much lower cost, making it suitable for resource-constraint settings. In addition, high frequency (>10%) of cryptic pathogenic IBMFS gene variations in IAA cohort suggests routine incorporation of targeted next-generation sequencing screening in these cases.

Impact of COVID-19 Pandemic on Clinical Care of Patients and Psychosocial Health of Affected Families with Chronic Granulomatous Disease: an Observational Study from North India.

Day-to-day clinical management of patients with inborn errors of immunity, including chronic granulomatous disease (CGD), has been affected by the coronavirus disease-2019 (COVID-19) pandemic. There is a dearth of information on impact of this pandemic on clinical care of children with CGD and psychological profile of the caretakers. Among the 101 patients with CGD followed up in our center, 5 children developed infection/complications associated with COVID-19. Four of these children had a mild clinical course, while 1 child developed features of multisystem inflammatory syndrome in children (MISC) requiring intravenous glucocorticoids. Parents and caretakers of CGD patients (n = 21) and 21 healthy adults with similar ages and genders were also evaluated on the following scales and questionnaires: COVID-19 Fear Scale (FCV 19S), Impact of Event Scale (IES-R), Depression, Anxiety, and Stress Scale (DASS 21), Preventive COVID-19 Behavior Scale (PCV 19BS), and a "COVID-19 Psychological wellbeing questionnaire." Median age of the parents/caregivers was 41.76 years (range: 28-60 years). Male:female ratio was 2:1. In the study group, 71.4% had higher IES scores compared to 14.3% in controls. The caregivers had a high prevalence of stress, anxiety, avoidance behavior, and depression compared to controls (p < 0.001). Children with CGD have had predominantly mild infection with COVID-19; however, caregivers/parents of these children were at risk of developing psychological distress. The COVID-19 pandemic has brought to light the importance of patients' and caretakers' mental health which needs periodic assessment and appropriate interventions.

Evaluation of immunodominant peptides of in vivo expressed mycobacterial antigens in an ELISA-based diagnostic assay for pulmonary tuberculosis.

Non-sputum-based biomarker assay is urgently required as per WHO's target product pipeline for diagnosis of tuberculosis. Therefore, the current study was designed to evaluate the utility of previously identified proteins, encoded by in vivo expressed mycobacterial transcripts in pulmonary tuberculosis, as diagnostic targets for a serodiagnostic assay. A total of 300 subjects were recruited including smear+, smear- pulmonary tuberculosis (PTB) patients, sarcoidosis patients, lung cancer patients and healthy controls. Proteins encoded by eight in vivo expressed transcripts selected from previous study including those encoded by two topmost expressed and six RD transcripts (Rv0986, Rv0971, Rv1965, Rv1971, Rv2351c, Rv2657c, Rv2674, Rv3121) were analyzed for B-cell epitopes by peptide arrays/bioinformatics. Enzyme-linked immunosorbent assay was used to evaluate the antibody response against the selected peptides in sera from PTB and controls. Overall 12 peptides were selected for serodiagnosis. All the peptides were initially screened for their antibody response. The peptide with highest sensitivity and specificity was further assessed for its serodiagnostic ability in all the study subjects. The mean absorbance values for antibody response to selected peptide were significantly higher (p<0.001) in PTB patients as compared to healthy controls; however, the sensitivity for diagnosis of PTB was 31% for smear+ and 20% for smear- PTB patients. Thus, the peptides encoded by in vivo expressed transcripts elicited a significant antibody response, but are not suitable candidates for serodiagnosis of PTB.

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.

Uncommon histopathological features of cytomegalovirus encephalitis and measles inclusion body encephalitis on autopsy in two patients with primary immunodeficiency.

PURPOSE: To describe the neuropathological findings in two patients with primary immunodeficiency who had fatal viral encephalitis. MATERIALS AND METHODS: Severe combined immunodeficiency (SCID) was confirmed in case 1 by genetic testing, while case 2 had features suggestive of combined immunodeficiency; however, whole exome sequencing showed no pathogenic variants. Autopsies were performed in both cases after an informed consent. A detailed sampling of the brain including extracranial organs was conducted. Immunohistochemistry and electron microscopy was also performed to confirm the presence of viruses. RESULTS: Besides evidence of cystic encephalomalacia observed in both cases, the brain in case 1 revealed cytomegalovirus (CMV) ventriculoencephalitis accompanied by an exuberant gemistocytic response in the entire white matter. Nuclei of gemistocytes were loaded with several CMV nuclear inclusions, which was confirmed by immunohistochemistry. Case 2 demonstrated features of measles inclusion body encephalitis with several viral inclusions within neurons and astrocytes. Rare giant cells were also seen. Measles virus was confirmed on immunohistochemistry and electron microscopy. Plausibly, there was paucity of microglial nodules in both cases. Superadded bacterial pneumonia with diffuse alveolar damage was also seen in both cases. CONCLUSION: These cases add to the spectrum of unusual histological features of viral encephalitis seen in patients with underlying primary immunodeficiency diseases.

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.

Utility of targeted next generation sequencing for inborn errors of immunity at a tertiary care centre in North India.

Inborn errors of immunity (IEI) are a heterogeneous group of monogenic disorders that include primary immunodeficiency's and other disorders affecting different aspects of the immune system. Next-Generation Sequencing (NGS) is an essential tool to diagnose IEI. We report our 3-year experience in setting up facilities for NGS for diagnosis of IEI in Chandigarh, North India. We used a targeted, customized gene panel of 44 genes known to result in IEI. Variant analysis was done using Ion Reporter software. The in-house NGS has enabled us to offer genetic diagnoses to patients with IEI at minimal costs. Of 121 patients who were included pathogenic variants were identified in 77 patients. These included patients with Chronic Granulomatous Disease, Severe Combined Immune Deficiency, leukocyte adhesion defect, X-linked agammaglobulinemia, Ataxia Telangiectasia, Hyper-IgE syndrome, Wiskott Aldrich syndrome, Mendelian susceptibility to mycobacterial diseases, Hyper-IgM syndrome, autoimmune lymphoproliferative syndrome, and GATA-2 deficiency. This manuscript discusses the challenges encountered while setting up and running targeted NGS for IEI in our unit. Genetic diagnosis has helped our patients with IEI in genetic counselling, prenatal diagnosis, and accessing appropriate therapeutic options.

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.

Unusual clinical manifestations and predominant stopgain ATM gene variants in a single centre cohort of ataxia telangiectasia from North India.

Germline ATM gene variations result in phenotypic heterogeneity characterized by a variable degree of disease severity. We retrospectively collected clinical, genetic, and immunological data of 26 cases with A-T. Clinical manifestations included oculocutaneous telangiectasia (100%), ataxia (100%), fever, loose stools or infection (67%), cerebellar atrophy (50%), nystagmus (8%), dysarthria (15.38%), and visual impairment (8%). Genetic analysis confirmed ATM gene variations in 16 unrelated cases. The most common type of variation was stopgain variants (56%). Immunoglobulin profile indicated reduced IgA, IgG, and IgM in 94%, 50%, and 20% cases, respectively. T cell lymphopenia was observed in 80% of cases among those investigated. Unusual presentations included an EBV-associated smooth muscle tumour located in the liver in one case and Hyper IgM syndrome-like presentation in two cases. Increased immunosenescence was observed in T-cell subsets (CD4+CD57+ and CD8+CD57+). T-cell receptor excision circles (TRECs) were reduced in 3/8 (37.50%) cases.

Utility of Immunohistochemistry and Immunofluorescence in Determining the Pathogenic Variants of Chronic Granulomatous Disease.

BACKGROUND: Chronic granulomatous disease (CGD) is a primary immunodeficiency disorder of phagocytes due to defects in any of the five subunits of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex. An initial diagnosis of CGD is made by flow cytometry-based dihydrorhodamine assay or nitro blue tetrazolium test, which is further confirmed by molecular assays. Expression of five subunits of NADPH oxidase components by either flow cytometric or western blot analysis provides clues toward the potential gene targets which are subsequently confirmed by various genetic assays. Immunohistochemistry (IHC) and immunofluorescence (IF) have never been earlier used to determine the expression of different subunits of NADPH oxidase system. We evaluated the utility of IHC and IF in determining the underlying pathogenic variants of CGD. MATERIALS AND METHODS: Twelve genetically confirmed cases of CGD, comprising of biopsy specimens (n = 6), tissue blocks from autopsy cases (n = 3), and cellblocks of cell pellet prepared from peripheral blood (n = 4) were included. IHC for p67phox and p47phox subunits and IF for cytochrome b558 were performed. RESULTS: All 4 cases with pathogenic variation of NCF2 gene showed loss of expression for p67phox subunit. Two cases with pathogenic variation of NCF1 gene showed loss of expression for p47phox subunit. Five cases, except a single case with CYBB gene pathogenic variation, showed loss of expression for cytochrome b558 on IF. Thus, loss of expression consistently matched with the underlying genetic defects assessed by sequencing. CONCLUSIONS: Our results confirm our hypothesis that IHC and IF are two rapid, economical, pathologist-friendly techniques providing pertinent information regarding the underlying pathogenic variants and such immuno-analysis can be easily performed on the tissue.

Autoimmunity in Wiskott-Aldrich Syndrome: Updated Perspectives.

Wiskott-Aldrich syndrome (WAS) is an uncommon X-linked combined-immunodeficiency disorder characterized by a triad of thrombocytopenia, eczema, and immunodeficiency. Patients with WAS are also predisposed to autoimmunity and malignancy. Autoimmune manifestations have been reported in 26%-72% of patients with WAS. Autoimmunity is an independent predictor of poor prognosis and predisposes to malignancy. Development of autoimmunity is also an early pointer of the need for hematopoietic stem-cell transplantation. In this manuscript, we have collated the published data and present a narrative review on autoimmune manifestations in WAS. A summary of currently proposed immunopathogenic mechanisms and genetic variants associated with development of autoimmunity in WAS is also included.

Wiskott Aldrich Syndrome: A Multi-Institutional Experience From India.

Background: Wiskott Aldrich syndrome (WAS) is characterized by bleeding manifestations, recurrent infections, eczema, autoimmunity, and malignancy. Over the last decade, improved awareness and better in-house diagnostic facilities at several centers in India has resulted in increased recognition of WAS. This study reports collated data across major primary immunodeficiency diseases (PID) centers in India that are involved in care of children with WAS and highlights the varied clinical presentations, genetic profile, and outcomes of patients in India. Methods: Request to share data was sent to multiple centers in India that are involved in care and management of patients with PID. Six centers provided requisite data that were compiled and analyzed. Results: In this multi-institutional cohort, clinical details of 108 patients who had a provisional diagnosis of WAS were received. Of these, 95 patients with 'definite WAS' were included Fourteen patients were classified as XLT and 81 patients as WAS. Median age at onset of symptoms of patients was 3 months (IQR 1.6, 6.0 months) and median age at diagnosis was 12 months (IQR 6,48 months). Clinical profile included bleeding episodes (92.6%), infections (84.2%), eczema (78.9%), various autoimmune manifestations (40%), and malignancy (2.1%). DNA analysis revealed 47 variants in 67 cases. Nonsense and missense variants were the most common (28.4% each), followed by small deletions (19.4%), and splice site defects (16.4%). We also report 24 novel variants, most of these being frameshift and nonsense mutations resulting in premature termination of protein synthesis. Prophylactic intravenous immunoglobulin (IVIg) was initiated in 52 patients (54.7%). Hematopoietic stem cell transplantation (HSCT) was carried out in 25 patients (26.3%). Of those transplanted, disease-free survival was seen in 15 patients (60%). Transplant related mortality was 36%. Outcome details were available for 89 patients. Of these, 37% had died till the time of this analysis. Median duration of follow-up was 36 months (range 2 weeks- 12 years; IQR 16.2 months- 70 months). Conclusions: We report the first nationwide cohort of patients with WAS from India. Bleeding episodes and infections are common manifestations. Mortality continues to be high as curative therapy is not accessible to most of our patients.