Comprehensive Report of Primary Immunodeficiency Disorders from a Tertiary Care Center in India

Profile of 208 patients with inborn errors of immunity at a tertiary care center in South India

Primary immune deficiencies or inborn errors of immunity (IEI) are a heterogeneous group of disorders that predispose affected individuals to infections, allergy, autoimmunity, autoinflammation and malignancies. IEIs are increasingly being recognized in the Indian subcontinent. Two hundred and eight patients diagnosed with an IEI during February 2017 to November 2021 at a tertiary care center in South India were included in the study. The clinical features, laboratory findings including microbiologic and genetic data, and treatment and outcome details were analyzed. The diagnosis of IEI was confirmed in a total of 208 patients (198 kindreds) based on relevant immunological tests and/or genetic tests. The male-to-female ratio was 1.8:1. Of the 208 patients, 72 (34.6%) were < 1 yr, 112 (53.8%) were 1-18 years, and 24 (11.5%) were above 18 years. The most common IEI in our cohort was SCID (17.7%) followed by CGD (12.9%) and CVID (9.1%). We also had a significant proportion of patients with DOCK8 deficiency (7.2%), LAD (6.2%) and six patients (2.8%) with autoinflammatory diseases. Autoimmunity was noted in forty-six (22%) patients. Molecular testing was performed in 152 patients by exome sequencing on the NGS platform, and a genetic variant was reported in 132 cases. Twenty-nine children underwent 34 HSCT, and 135 patients remain on supportive therapy such as immunoglobulin replacement and/or antimicrobial prophylaxis. Fifty-nine (28.3%) patients died during the study period, and infections were the predominant cause of mortality. Seven families underwent prenatal testing in the subsequent pregnancy. We describe the profile of 208 patients with IEI, and to the best of our knowledge, this represents the largest data on IEI from the Indian subcontinent reported so far.

Clinical and Genetic Spectrum of Inborn Errors of Immunity in a Tertiary Care Center in Southern India

OBJECTIVES

To study the incidence, clinical manifestations, and genetic spectrum of primary immunodeficiency diseases (PID)/inborn errors of immunity (IEI) in a tertiary care hospital in Southern India.

METHODS

A retrospective analysis of all patients with a clinical suspicion of PID/IEI seen at a tertiary care hospital was performed. All patients had at least one or more warning signs of PID. Serum immunoglobulin levels and other targeted investigations were performed as warranted by the clinical presentation. All families with suspected PID were counseled and offered genetic testing.

RESULTS

A total of 225 children were evaluated for PID during the study period of 6 y. Fifty-six of them did not meet the European Society of Immunodeficiencies (ESID) criteria (working definition of clinical diagnosis) and were excluded. An IEI was found in 30/49 (61.2%) patients. The most frequent reason for referral was recurrent/unusual or serious infections (28%), or cytopenia (16%). Group IV diseases of immune dysregulation was the most common category (19%), followed by group III predominant antibody deficiencies in 23/163 (14%), as per the International Union of Immunological Societies (IUIS) classification.

CONCLUSIONS

This study highlights the heterogeneity of the present cohort, the underuse of genetic tests, and efforts to provide optimal care for children with possible IEI in this center.

Primary Immunodeficiencies in India: Molecular Diagnosis and the Role of Next-Generation Sequencing

Primary immunodeficiency diseases (PIDs) are a group of clinically and genetically heterogeneous disorders showing ethnic and geographic diversities. Next-generation sequencing (NGS) is a comprehensive tool to diagnose PID. Although PID is common in India, data on the genetic spectrum of PIDs are limited due to financial restrictions. The study aims to characterize the clinical and genetic spectrum of PID patients in India and highlight the importance of a cost-effective targeted gene panel sequencing approach for PID in a resource-limited setting. The study includes 229 patients with clinical and laboratory features suggestive of PIDs. Mutation analysis was done by Sanger sequencing and NGS targeting a customized panel of genes. Pathogenic variants were identified in 97 patients involving 42 different genes with BTK and IL12RB1 being the most common mutated genes. Autosomal recessive and X-linked recessive inheritance were seen in 51.6% and 23.7% of patients. Mendelian susceptibility to mycobacterial diseases (MSMD) and IL12RB1 mutations was more common in our population compared to the Western world and the Middle East. Two patients with hypomorphic RAG1 mutations and one female with skewed CYBB mutation were also identified. Another 40 patients had variants classified as variants of uncertain significance (VUS). The study shows that targeted NGS is an effective diagnostic strategy for PIDs in countries with limited diagnostic resources. Molecular diagnosis of PID helps in genetic counseling and to make therapeutic decisions including the need for a stem cell transplantation.

Indian Antimicrobial Prescription Guidelines in Critically Ill Immunocompromised Patients

How to cite this article: Kulkarni AP, Sengar M, Chinnaswamy G, Hegde A, Rodrigues C, Soman R, Khilnani GC, Ramasubban S, Desai M, Pandit R, Khasne R, Shetty A, Gilada T, Bhosale S, Kothekar A, Dixit S, Zirpe K, Mehta Y, Pulinilkunnathil JG, Bhagat V, Khan MS, Narkhede AM, Baliga N, Ammapalli S, Bamne S, Turkar S, Bhat KV, Choudhary J, Kumar R, Divatia JV. Indian Journal of Critical Care Medicine 2019;23(Suppl 1): S64-S96.

Poliovirus Excretion in Children with Primary Immunodeficiency Disorders, India

Prolonged excretion of poliovirus can occur in immunodeficient patients who receive oral polio vaccine, which may lead to propagation of highly divergent vaccine-derived polioviruses (VDPVs), posing a concern for global polio eradication. This study aimed to estimate the proportion of primary immunodeficient children with enterovirus infection and to identify the long-term polio/nonpolio enterovirus excreters in a tertiary care unit in Mumbai, India. During September 2014–April 2017, 151 patients received diagnoses of primary immunodeficiency (PID). We isolated 8 enteroviruses (3 polioviruses and 5 nonpolio enteroviruses) in cell culture of 105 fecal samples collected from 42 patients. Only 1 patient with severe combined immunodeficiency was identified as a long-term VDPV3 excreter (for 2 years after identification of infection). Our results show that the risk of enterovirus excretion among children in India with PID is low; however, systematic screening is necessary to identify long-term poliovirus excreters until the use of oral polio vaccine is stopped.

Latent therapeutic demand model for the immunoglobulin replacement therapy of primary immune deficiency disorders in the USA

BACKGROUND AND OBJECTIVES

Our research aim is to model latent therapeutic demand (LTD) for the immunoglobulin replacement therapy (IgGRT) of primary immune deficiency disorders (PIDDs) in the USA. Given the high level of variability of IgGRT use and major differences among American and European practices in the management of patients with PIDDs, we develop a USA-specific LTD model for common variable immune deficiency (CVID), hyper IGM syndrome, severe combined immune deficiency, Wiskott-Aldrich syndrome and X-linked agammaglobulinemia (XLA).

METHODS AND MATERIALS

We use decision analysis methods to model the underlying IgGRT demand for PIDDs by assessing USA-specific epidemiology and treatment. Data for the epidemiology and treatment variables were obtained from the medical literature, USIDNET and Immune Deficiency Foundation. The uncertainty surrounding the variables was modelled using probability distributions and evaluated using Monte Carlo simulation.

RESULTS

The mean treatment dose from USIDNET and European Society for Immunodeficiencies (ESID) was significantly different for treating CVID, and the number of annual infusions from USIDNET and ESID was significantly different for treating CVID and XLA. The mean and standard deviation of LTD for all PIDDs is 105·1 ± 88·5 g per 1000 population, with CVID contributing the most to LTD.

CONCLUSION

Estimating country-specific LTD is important to ensure an adequate supply of IgGRT and an optimal treatment for patients with PIDDs and for improving national healthcare policymaking and production planning.

X-linked agammaglobulinemia: Twenty years of single-center experience from North West India

BACKGROUND

X-linked agammaglobulinemia (XLA) is an X-linked genetic defect in maturation of B lymphocytes that results in the absence of B lymphocytes in the peripheral blood and profound hypogammaglobulinemia. It is caused by a mutation in the BTK gene located on the X chromosome. There are no large series describing XLA from the developing world.

OBJECTIVE

To analyze the clinical features, immunologic and genetic characteristics, and outcomes of 36 patients with XLA diagnosed and managed for a period of 2 decades.

METHODS

Diagnosis of XLA was made on the basis of presence of BTK gene mutation or marked reduction of B lymphocytes in peripheral blood with a family history of an affected male relative. The diagnosis was confirmed by genetic mutation studies in 28 patients with 25 unique mutations in the BTK gene.

RESULTS

There was a significant delay in diagnosis in most of the patients. The mean (SD) delay in the diagnosis was 4.2 (3.5) years. Point mutations were the most common mutations detected, accounting for 68% of all mutations. Deletions and insertions were also seen in a few cases. Four of the mutations are novel mutations that have not been previously reported. Seven of the 36 patients (19%) were dead at the time of analysis in the present cohort. The mean survival was 137 months (95% confidence interval, 13-163 months).

CONCLUSION

The present study is perhaps the largest series of patients with XLA from any developing country so far.

Guidelines for Screening, Early Diagnosis and Management of Severe Combined Immunodeficiency (SCID) in India

Severe combined immunodeficiency (SCID) is one of the most severe and fatal forms of inherited primary immunodeficiency. Early diagnosis of SCID improves the outcome of life before and after hematopoietic stem cell transplant (HSCT). SCID fulfills the internationally-established criteria for a condition to be screened for at birth. T cell receptor excision circle (TREC) assay is commonly used in western countries as part of newborn blood spot screening (NBS) program as the assay has high sensitivity and specificity to identify SCID infants, allowing early intervention and curative bone marrow (BM) transplantation. In India, the blood spot based screening programs are yet to mature into a full-fledged national program. Moreover, TREC assay, a PCR based test, is not widely available and may cost USD 5-7 per test; thus limiting its applicability for screening newborns in Indian scenario. Most of the SCID patients have lymphopenia at birth and routine evaluation for absolute lymphocyte count (ALC) on cord blood samples can help in pre-symptomatic detection and early intervention for neonates with SCID. Although ALC count lacks the sensitivity and specificity of TREC assay; its lower cost and widespread availability makes it an attractive option for identifying newborns with lymphopenia during the post-partum hospital stay. BCG vaccine and other live attenuated vaccines (e.g., oral polio vaccine) should be withheld in lymphopenic infants until SCID is excluded by clinical and/or immunological work-up. A diagnosis of SCID warrants immediate care to prevent and treat infections and wherever feasible, early stem cell transplantation for disease free survival.

Current Updates on Classification, Diagnosis and Treatment of Hemophagocytic Lymphohistiocytosis (HLH)

Hemophagocytic lymphohistiocytosis (HLH) is a life threatening hyperinflammatory syndrome characterized by excessive activation of macrophages and T cells resulting from defective cytotoxicity. Severe hyperinflammation caused by uncontrolled proliferation of activated lymphocytes and histiocytes (macrophages) secreting high amounts of inflammatory cytokines threatens the life of the patient and may lead to death unless arrested by appropriate treatment. HLH can be caused either by certain underlying genetic diseases (familial HLH), or may also occur due to particular triggers in patients with no known inherited disorder (acquired HLH). Due to life threatening nature of the disease, early diagnosis and initiation of immunosuppressive therapy is extremely important. HLH diagnosis is based on constellation of clinical manifestations and laboratory parameters which often overlap with those of severe infection or sepsis. Identification of patients with familial HLH and their underlying genetic defects requires specialized laboratory tests and is important for predicting relapses and planning early therapeutic hematopoietic stem cell transplantation (HSCT). A high suspicion and thorough clinical, immunological and genetic work-up is required for diagnosis of HLH. Prompt initiation of adequate treatment is essential for the survival. Substantial progress has been made in exploring the complex cause and pathophysiology of HLH and also in management of HLH patients.

The use of databases in primary immunodeficiencies

PURPOSE OF REVIEW

We provide an overview on the latest developments in primary immunodeficiency registries worldwide, on the basis of the recent literature amended by some older references to achieve completeness.

RECENT FINDINGS

New primary immunodeficiency registries are emerging worldwide, although existing databases continue to thrive and provide valuable insights for clinicians and researchers.

SUMMARY

In the area of rare disease research, data on a meaningful number of patients can only be achieved via collaboration. Registries for primary immunodeficiency are organized on different geographic levels and appear in various technical forms. Some registries are operated within single departments or hospitals, whereas others collect data from a country in the form of a national registry. With modern information technology and networks, it has become feasible to easily extend documentation to the transnational level. Most patient registries cover similar but not identical sets of data, whereas some have a special focus on, for example, genetics or incorporate only data from patients who have undergone a specific form of treatment. This review shows the usefulness and power of international immunodeficiency registries, as well as possible hurdles and limitations.

Molecular characterization of leukocyte adhesion deficiency-I in Indian patients: identification of 9 novel mutations

PURPOSE

Leukocyte adhesion deficiency type-I (LAD-I) is caused by mutations in the ITGB2 gene, encoding the β2-subunit of β2-integrin (CD18) which leads to markedly reduced expression of CD18 on leukocytes resulting into recurrent life threatening infections. Here we aim to identify the molecular defects underlying LAD-I in Indian patients and correlate with the clinical presentation.

METHODS

Blood was collected from 30 patients and their parents for absolute neutrophil count, expression of CD18 and CD11 by flow cytometry and DNA extraction. PCR and DNA sequencing of the ITGB2 gene was done for mutation characterization.

RESULTS

Phenotypically, 22 patients were LAD-I(0), 1 was LAD-I(-) and 7 were LAD-I(+) showing no expression and reduced expression of CD18 respectively. Nine novel mutations in 15 patients and 11 known mutations in 16 patients were detected. Prenatal diagnosis was performed for 5 families.

CONCLUSION

In this study 30 patients were phenotypically and genotypically evaluated for a less known disease LAD-I. Unavailability of curative options to majority of the patients and high cost of supportive care emphasize the need to increase awareness about a suspicious case so that timely management can be given to the patient and prenatal diagnosis can be offered to their families.

Primary immunodeficiency disorders in the developing world: data from a hospital-based registry in India

Primary immunodeficiency disorders (PID) are under-reported from the developing world. We present data regarding diagnosis and outcome from a hospital-based registry in India. Forty-seven patients fulfilled diagnostic criteria. Majority were males. Subgroups were disorders of immune dysregulation-29%, B&T-cell abnormalities-28%, predominant antibody deficiencies-23%, other well-defined immunodeficiencies-15%, and phagocyte disorders-4%. Molecular diagnosis was attempted in 12 and was positive in seven. Overall 24 children died. Only three out of 28 children needing stem cell transplant (SCT) underwent the same. Registry data highlights that molecular diagnosis and SCT are a rarity for children with PIDs in the developing world and mortality is high.

X linked agammaglobulinemia: a single centre experience from India

The authors report a series of seven cases of X-linked Agammaglobulinemia, diagnosed and receiving treatment at a tertiary care centre in Mumbai. The ages of the patients ranged from 15 mo to 15 y. After diagnosis at a mean age of 3 ½ y, all were advised intravenous immunoglobulin (IvIg) infusion therapy in doses of 400-600 mg/kg every 3-4 wk. They were followed up for an average duration of 9 y, throughout which the complications and overall response to immunoglobulin therapy have been observed. The clinical profiles of each of these cases were retrospectively analysed with respect to age at diagnosis, frequency and severity of infections before and after initiation of treatment, co-morbidities and response to therapy. The results demonstrate the importance of early diagnosis and its correlation with decreased complications.

Spectrum of primary immunodeficiency disorders in Sri Lanka

Background

While primary immunodeficiencies (PID has been recognized in the west for decades, recognition has been delayed in the third world. This study attempts to detail the spectrum of PID, the therapy provided, and constraints in the diagnosis and treatment in a middle income country such as Sri Lanka.

Methods

Nine hundred and forty two patients with recurrent infections and features suggestive of immune deficiency, referred from the entire country in a 4 year period, to the sole immunology unit in Sri Lanka were included. The following tests were performed. Full blood counts, serum Immunoglobulin and complement C3 and C4 levels, functional antibody levels, enumeration of lymphocyte subsets, in vitro and in vivo T cell functional assays,, nitroblue tetrazolium assay to diagnose chronic granulomatous disease, hair shaft assay to diagnose Griscelli syndrome. Sequencing of the common gamma chain to identify x linked severe combined immune deficiency, and X linked agammaglobulinemia was confirmed by assaying for Btk mutations by single sequence conformation polymorphism. HIV/AIDS was excluded in all patients.

Results

Seventy three patients were diagnosed with a primary immune deficiency. The majority (60.27%) had antibody deficiency. Common variable immune deficiency was the commonest (28.76%), followed by X linked agammaglobulinemia (XLA) (20.54%). Five patients had possible hyper IgM syndrome.

Ten patients had severe combined immune deficiency (SCID), including 2 with x linked SCID, in addition to DiGeorge syndrome (2), ataxia telangiectasia (6), autosomal dominant hyper IgE syndrome (2), chronic granulomatous disease (4), leucocyte adhesion deficiency type 1 (2) and Griscelli syndrome (3).

Patients with autoinflammatory, innate immune and complement defects could not be identified due to lack of facilities.

Conclusions

Antibody deficiency is the commonest PID, as in the west.IgA deficiency is rare. Autoinflammatory diseases, innate immune and complement deficiencies could not be identified due to lack of diagnostic facilities. Lack of awareness of PID among adult physicians result in delay in treatment of adult patients. While treatment of antibody deficiencies provided in state hospitals has extended life expectancy, there is no treatment available for severe T cell defects.