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.

Transmission patterns of C1-INH deficiency hereditary angioedema favors a wild-type male offspring: Our experience at Chandigarh, India.

BACKGROUND: Deficiency of C1-inhibitor (C1-INH) protein, caused by pathogenic variants in the Serpin family G member 1 (SERPING1) gene, is the commonest pathophysiological abnormality (in ∼95 % cases) in patients with hereditary angioedema (HAE). C1-INH protein provides negative control over kallikrein-kinin system (KKS). Although the inheritance of the HAE-C1-INH is autosomal dominant, female predominance has often been observed in patients with HAE. OBJECTIVE: To analyze the risk of transmission of SERPING1 gene variant from father or mother to their offspring. METHODS: Pedigree charts of 42 families with a confirmed diagnosis of HAE-C1-INH and a pathogenic variant in the SERPING1 gene were analysed. Patients with HAE who had had at least one child were included for analyses to assess the risk of transmission from the father or mother to their offspring. RESULTS: Overall, 49 % (189/385) of all offspring inherited the genetic defect. In the subgroup analyses, 54.8 % (90/164) female offspring and 44.8 % (99/221; p < 0.02) male offspring inherited the genetic defect. Inheritance of the genetic defect was significantly lower in male offspring. Fathers with SERPING1 gene variant had a statistically significant skewed transmission of the wild type to the male offspring as compared to the variant (57.8 % wild type vs. 42.1 % variant; p < 0.02), whereas no statistically significant difference was found when a father transmitted the variant to a female offspring. Mothers with SERPING1 gene variant had no statistically significant difference in variant transmission to male or female offsprings. CONCLUSION: Results of the study suggest that the transmission pattern of SERPING1 gene variant favours the transmission of wild-type alleles in males, especially when the father is the carrier; hence, overall, fewer males and more female offspring inherited the variant. This could be because of a selection of wild-type male sperms during spermatogenesis, as the KLK system has been reported to play a crucial role in the regulation of spermatogenesis. Although, a similar pattern was observed in the maternal transmission of the SERPING1 gene variant; the difference was not statistically significant, likely because of a small sample size.

Delays in diagnosis is the commonest proximate reason for mortality in hereditary angioedema: our experience at Chandigarh, India.

BACKGROUND: Hereditary angioedema (HAE) is a rare autosomal dominant disorder characterized clinically by recurrent episodes of non-pruritic subcutaneous and/or submucosal edema. Laryngeal edema is the commonest cause of mortality in patients with HAE. Prior to the availability of first-line treatment options for management of HAE, the mortality used to be as high as 30%. The mortality has significantly reduced in countries where first-line treatment options are available and patients can access these therapies. There is paucity of literature on the outcomes of patients with HAE in developing countries where availability and access to first-line treatment options is still a challenge. OBJECTIVE: To report our experience with mortality in patients with HAE and to report factors associated with death of these patients. METHODS: We carried out a record review of all patients diagnosed to have HAE between January 1996 and August 2022. Families with HAE who had reported death of at least one family member/relative because of laryngeal edema were studied in detail. RESULTS: Of the sixty-five families (one hundred and seventy patients) registered in the clinic, sixteen families reported death of at least one family member/relative because of laryngeal edema (total thirty-six deaths). Of these sixteen families, fourteen families reported that one or more family members had experienced at least one attack of laryngeal edema. One patient died during follow-up when she was taking long-term prophylaxis with stanozolol and tranexamic acid while remaining thirty-five patients were not diagnosed to have HAE at the time of their death. At the time of death of all thirty-six patients, at least one other family member had symptoms suggestive of HAE but the diagnosis was not established for the family. CONCLUSIONS: This is the largest single centre cohort of patients with HAE in India reporting mortality data and factors associated with death in these families. Delay in diagnosis is the commonest reason for mortality.

Fatal COVID-19 Infection in Two Children with STAT1 Gain-of-Function.

While SARS-CoV-2 infection causes a mild disease in most children, SARS-CoV-2 infection may be lethal in a few of them. In the defense against SARS-CoV-2, type I interferons are key players, and several studies have identified a defective or neutralized interferon response as the cause of overwhelming viral infection. However, inappropriate, untimely, or excessive interferon production may also be detrimental to the host. Here, we describe two patients with STAT1 gain-of-function (GOF), a known type I interferonopathy, who died of COVID-19. Whole-exome sequencing and interferon-gamma-activated sequence (GAS) and interferon-sensitive responsive element (ISRE) reporter assay were performed to identify and characterize STAT1 variants. Patient 1 developed hemophagocytic lymphohistiocytosis (HLH) in the context of COVID-19 infection and died in less than a week at the age of 4 years. Patient 2 developed a high fever, cough, and hypoxemia and succumbed to COVID-19 pneumonia at the age of 5 years. Two heterozygous missense variants, p.E563Q and p.K344E, in STAT1 were identified. Functional validation by reporter assay and immunoblot confirmed that both variants are gain-of-function (GOF). GOF variants transiently expressing cells exhibited enhanced upregulation of downstream genes, including ISG15, MX1, and OAS1, in response to IFN-α stimulation. A catastrophic course with HLH or acute respiratory failure is thought to be associated with inappropriate immunoregulatory mechanisms to handle SARS-CoV-2 in STAT1 GOF. While most patients with inborn errors of immunity who developed COVID-19 seem to handle it well, these cases suggest that patients with STAT1-GOF might be at risk of developing fatal complications due to SARS-CoV-2.

Case report: Corticosteroids as an adjunct treatment for the management of liver abscess in Papillon-Lefèvre syndrome: A report on two cases.

Papillon-Lefèvre syndrome (PLS) is a rare autosomal recessive disorder characterized clinically by palmoplantar keratoderma, periodontitis, and recurrent pyogenic infections. Liver abscess is rarely reported in patients. The use of corticosteroids for the treatment of liver abscess akin to chronic granulomatous disease (CGD) has not been reported previously. Here, we report 2 cases of liver abscess in PLS that responded to corticosteroids.

Folate Deficiency: A Possible Association with Congenital Heart Defects.

Congenital heart defects continue to remain a major cause of serious morbidity and mortality, especially in the developing world. This study was planned to get some insight into the role of modifiable nutritional elements in structural CHD etiology. This cross-sectional, observational study was conducted at a hospital in Northern India from January 2017 to December 2017. Infants < 6 mo with structural CHD as cases and those without structural heart disease were enrolled as controls. Blood samples were collected from mother-child pairs and tested for serum folate, vitamin B12, and homocysteine. It was found that 46.7% infant-mother pairs, out of 45 in the cases group had folate deficiency, whereas in the control group, only 20% had folate deficiency, which was statistically significant (p = 0.013). Baby (0-6 mo) with congenital heart defects (CHD) and their mothers are more likely to have low folate levels compared to those not having CHD.

Disseminated drug-resistant tuberculosis and multiple autoimmune syndrome in a child with selective IgA deficiency-An uncustomary combination.

Polyautoimmunity or multiple autoimmune syndrome (MAIS) is increasingly being recognized in pediatric clinical practice, often in conjunction with systemic lupus erythematosus (SLE). Besides multi-organ autoimmunity, children with SLE are often at a higher risk of developing infections including tuberculosis. The tendency to develop infections and multiple autoimmune diseases in childhood SLE often occurs in the absence of monogenic primary immunodeficiency disease. Conversely, children with inborn errors of immunity, of which selective IgA deficiency (sIgAD) is the most common, may develop recurrent infections and autoimmune disorders including SLE. Herein, we report a child with MAIS (including SLE) and sIgAD who developed drug-resistant tuberculosis, which was managed successfully with second-line anti-tubercular drug therapy. To the best of our knowledge, this combination of rare findings has not been reported previously in the pediatric literature. Although a majority of patients with sIgAD are either asymptomatic or have mild infections/autoimmunity, the index child had a myriad of infectious illnesses and multi-organ autoimmunity. Our case highlights the prudence of thoroughly evaluating children with SLE for other autoimmune diseases and vice versa. Given the higher probability of inherited disorders, including early complement deficiencies and monogenic interferonopathies, in childhood SLE compared with adult SLE, it may be prudent to perform a basic immunological workup (for example, immunoglobulin levels, 50% hemolytic complement) in such patients. A more extensive immunological and genetic evaluation (including next-generation sequencing) may also be required in the presence of unusual clinical or laboratory features, a positive family history, or a complicated clinical course.