Volume 9 • Number 4 • December 2022
Original Artilce
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Background: Autoinflammatory diseases are a genetically heterogeneous group of conditions characterized by excessive activation of the innate immune system. They frequently present with overlapping features, particularly in cases of digenic or polygenic inheritance. The most common cause of autoinflammation arises from causative variants in the MEFV gene, responsible for familial Mediterranean fever. Clinical features include recurrent episodes of fever with serositis and amyloidosis. Individuals with variants in MEFV that present atypically with heterogeneous autoinflammatory features have also been described. Notably, gene modifiers of MEFV, such as NOD2 encoding an intracellular bacterial sensor, can result in more severe disease. NOD2 underlies a number of autoinflammatory and immunodeficiency conditions, including Blau syndrome. To date, Blau syndrome has not been described in the context of MEFV.Aim: To expand the presentation and phenotype of autoinflammatory disease associated with defects in the NOD2 and MEFV genes.Methods: A retrospective review of the patient’s chart was performed, including family history, medical history, immune laboratory evaluation, and genetics.Results: We describe here a 68-year-old male with a remarkable medical history since childhood of skin rash, erythroderma, recurrent infections, autoinflammation, arthritis, uveitis, and malignancy. A significant family history of cancer and autoinflammation was noted. Genetic work-up involving a 17-gene autoinflammatory panel revealed 3 heterozygous variants of uncertain significance, 2 of which were present in the MEFV gene and one in the NOD2 gene. His features were consistent with an overlapping phenotype of Blau syndrome and atypical FMF.Conclusion: Heterozygous variants in NOD2 and MEFV can result in a spectrum of autoinflammatory disorders with a heterogeneous phenotype. The NOD2 variant identified in our patient has not previously been associated with Blau syndrome.Statement of Novelty: We describe a patient harbouring heterozygous mutations in the MEFV and NOD2 genes marked by recurrent childhood infections.
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Background: Hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening disease in which cells of the immune system are overactivated, leading to uncontrolled inflammation and tissue destruction. Inherited or familial forms of HLH (FHL) are further classified into FHL1 to 5, based on the underlying genetic etiology. The most common form, FHL2, is associated with mutations in the PRF1 gene encoding perforin, a pore-forming glycoprotein required for natural killer and cytotoxic T cell-mediated apoptosis. Importantly, diagnosis of FHL can be challenging, particularly in late-onset cases in which presentation is delayed beyond the first years of life.Aim: We report the essential role of whole exome sequencing in the diagnostic work-up of a patient with complex, late-onset FHL.Methods: A comprehensive retrospective chart review was performed.Results: Our patient presented at 11 years of age with recurrent fever, hepatosplenomegaly, and pancytopenia. In the following years, she was admitted to hospital on multiple occasions, including twice for febrile neutropenia, and once for febrile cytopenia. Serial immune evaluation revealed features of immune dysregulation. While HLH was suspected, she did not fulfil the diagnostic criteria. Initial genetic work-up involving a targeted primary immunodeficiency gene panel identified only a single novel variant of uncertain significance, c.T374C (p.I125T) in PRF1. Subsequently, research-based whole exome sequencing was performed which revealed a second variant, c.C272T (p.A91V), in the same gene. The expanded genetic findings, a set of compound heterozygous missense mutations in PRF1, strengthened the diagnosis of FHL. She later fulfilled the diagnostic criteria for HLH.Conclusion: Whole exome sequencing identified compound heterozygous mutations in the PRF1 gene in a patient with late-onset FHL.Statement of Novelty: We report the use of whole exome sequencing to identify compound heterozygous mutations in PRF1, including a novel p.I125T variant not previously identified in FHL.
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Background: Polyclonal hypergammaglobulinemia (PHGG) is commonly associated with liver disorders and could signify an enhanced or defective immune system. This study was conducted to determine the distribution and significance of PHGG in phases of chronic hepatitis B infection (CHB).Methods: Serum protein electrophoresis and colorimetric protein were assayed in 80 inactive (IA), 45 immune-clearance (IC) and 17 immune-escape (IE) CHB participants. ANOVA and Student’s t-test were used for the comparison of data, while area under curve analysis was used to assess the performance.Results: A significant elevation in γ-globulin was observed in the 3 phases studied in relation to non-hepatitis B virus-infected controls. The incidence of PHGG in different phases of CHB are IA (61.3%), IC (33.3%), and IE (29.4%). The IA phase, considered the least severe, has the highest incidence of PHGG.Conclusion: Occurrence of PHGG seems to signify enhanced immune responses. It may also be used to some extent to predict the IA phase.Statement of novelty: This study utilized both qualitative and quantitative methods to evaluate the patterns of PHGG in untreated and categorized CHB infections.