Manish Butte

Eur J Immunol. 2022 Jul 27. doi: 10.1002/eji.202149667. Online ahead of print.

ABSTRACT

Rituximab (RTX), a chimeric monoclonal antibody targeting CD20-positive cells, is a valuable treatment option for malignant and benign immune-related disorders. The rationale of targeting the CD20 antigen relies on depletion of both healthy and autoreactive/malignant CD20-espressing cells, but normal B cell reconstitution is expected within months after treatment. Nevertheless, a number of recent studies have documented prolonged B cell deficiency associated with new-onset hypogammaglobulinemia in patients receiving RTX. Awareness of post-RTX hypogammaglobulinemia has become wider among clinicians, with a growing number of reports about the increased incidence, especially in children. Although these patients were previously regarded as affected by secondary/iatrogenic immunodeficiency, atypical clinical and immunological manifestations (e.g. severe or opportunistic infections; prolonged B cell aplasia) raise concerns of delayed manifestations of genetic immunological disorders that have been unveiled by B cell perturbation. As more patients with undiagnosed primary immune deficiency (PID) receiving RTX have been identified, it remains the challenge in discerning those that might display a higher risk of persistent RTX-associated hypogammaglobulinemia and need a tailored immunology follow-up. In this review we summarize the principal evidence regarding post-RTX hypogammaglobulinemia and provide a guideline for identifying patients at higher risk of RTX-associated hypogammaglobulinemia that could harbor an inborn error of immunity. This article is protected by copyright. All rights reserved.

PMID:35892275 | DOI:10.1002/eji.202149667

Viruses. 2022 Jun 28;14(7):1423. doi: 10.3390/v14071423.

ABSTRACT

Alphaviruses cause significant outbreaks of febrile illness and debilitating multi-joint arthritis for prolonged periods after initial infection. We have previously reported that several host hnRNP proteins bind to the Sindbis virus (SINV) RNAs, and disrupting the sites of these RNA-protein interactions results in decreased viral titers in tissue culture models of infection. Intriguingly, the primary molecular defect associated with the disruption of the hnRNP interactions is enhanced viral structural protein expression; however, the precise underlying mechanisms spurring the enhanced gene expression remain unknown. Moreover, our previous efforts were unable to functionally dissect whether the observed phenotypes were due to the loss of hnRNP binding or the incorporation of polymorphisms into the primary nucleotide sequence of SINV. To determine if the loss of hnRNP binding was the primary cause of attenuation or if the disruption of the RNA sequence itself was responsible for the observed phenotypes, we utilized an innovative protein tethering approach to restore the binding of the hnRNP proteins in the absence of the native interaction site. Specifically, we reconstituted the hnRNP I interaction by incorporating the 20nt bovine immunodeficiency virus transactivation RNA response (BIV-TAR) at the site of the native hnRNP I interaction sequence, which will bind with high specificity to proteins tagged with a TAT peptide. The reestablishment of the hnRNP I-vRNA interaction via the BIV-TAR/TAT tethering approach restored the phenotype back to wild-type levels. This included an apparent decrease in structural protein expression in the absence of the native primary nucleotide sequences corresponding to the hnRNP I interaction site. Collectively, the characterization of the hnRNP I interaction site elucidated the role of hnRNPs during viral infection.

PMID:35891402 | DOI:10.3390/v14071423

Vaccines (Basel). 2022 Jul 18;10(7):1141. doi: 10.3390/vaccines10071141.

ABSTRACT

Information on the efficacy and safety of molnupiravir in daily clinical practice is very scarce. We aimed to describe the clinical characteristics and outcomes of fully vaccinated patients with mild to moderate breakthrough COVID-19 treated with molnupiravir between January 2022 and February 2022. Overall, 145 patients were enrolled. Their median age was 71.0 years, and 60.7% were males. The most common underlying condition was a severe cardiovascular disease (37.2%), followed by primary or acquired immunodeficiency (22.8%), and oncological/onco-hematological disease in the active phase (22.1%). At 30 days after breakthrough COVID-19 diagnosis, only 4 out of 145 patients (2.7%) required hospital admission. No patients developed severe COVID-19, were admitted to the ICU, or died during the follow-up period. Adverse events, mild in intensity, occurred in 2 patients (1.4%). Our results support the current evidence establishing positive clinical and safety outcomes of molnupiravir in fully vaccinated patients with mild or moderate breakthrough COVID-19.

PMID:35891305 | DOI:10.3390/vaccines10071141

J Clin Med. 2022 Jul 20;11(14):4220. doi: 10.3390/jcm11144220.

ABSTRACT

Inborn errors of immunity (IEI), formerly known as primary immunodeficiency disorders (PIDs), are inherited disorders caused by damaging germline variants in single genes, which result in increased susceptibility to infections and in allergic, autoimmune, autoinflammatory, nonmalignant lymphoproliferative, and neoplastic conditions. Along with well-known warning signs of PID, attention should be paid to signs of immune dysregulation, which seem to be equally important to susceptibility to infection in defining IEI. The modern diagnostics of IEI offer a variety of approaches but with some problems. The aim of this review is to discuss the diagnostic challenges in IEI patients in the context of an immune dysregulation background.

PMID:35887984 | DOI:10.3390/jcm11144220

Clin Pediatr (Phila). 2022 Jul 26:99228221113630. doi: 10.1177/00099228221113630. Online ahead of print.

ABSTRACT

To our knowledge, late, late-onset group B streptococcal (GBS) meningitis in identical twins has yet to be reported. We describe a case of 14-week-old twins who developed fever hours apart and presented simultaneously to the emergency department 2 days later with seizures. Blood and cerebrospinal fluid (CSF) cultures from both infants were positive for GBS. Their clinical courses were highly similar, with magnetic resonance imaging (MRI) demonstrating ventriculitis and subdural empyema, complicated by clinical and subclinical seizures requiring quadruple antiepileptic treatment. The CSF was sterile for both on follow-up lumbar puncture 48 hours after the initial positive CSF culture. Both showed marked improvement on antimicrobial and antiepileptic therapy, with fever resolving after 5 days of therapy, control of seizures, and slowly improving MRI findings. Twin A received a 6-week course of penicillin, whereas twin B received 6 weeks plus an additional 10 days due to persistent left cochlear enhancement consistent with labyrinthitis. Evaluation for an underlying primary immunodeficiency was negative. Genomic analysis revealed that the patients’ CSF GBS isolates were essentially identical and of capsular polysaccharide serotype Ia.

PMID:35883267 | DOI:10.1177/00099228221113630

Ann Clin Transl Neurol. 2022 Jul 25. doi: 10.1002/acn3.51634. Online ahead of print.

ABSTRACT

OBJECTIVE: Intracellular signaling networks rely on proper membrane organization to control an array of cellular processes such as metabolism, proliferation, apoptosis, and macroautophagy in eukaryotic cells and organisms. Phosphatidylinositol 4-phosphate (PI4P) emerged as an essential regulatory lipid within organelle membranes that defines their lipid composition and signaling properties. PI4P is generated by four distinct phosphatidylinositol 4-kinases (PI4K) in mammalian cells: PI4KA, PI4KB, PI4K2A, PI4K2B. Animal models and human genetic studies suggest vital roles of PI4K enzymes in development and function of various organs, including the nervous system. Bi-allelic variants in PI4KA were recently associated with neurodevelopmental disorders (NDD), brain malformations, leukodystrophy, primary immunodeficiency, and inflammatory bowel disease. Here, we describe patients from two unrelated consanguineous families with PI4K2A deficiency and functionally explored the pathogenic mechanism.

METHODS: Two patients with PI4K2A deficiency were identified by exome sequencing, presenting with developmental and epileptic-dyskinetic encephalopathy. Neuroimaging showed corpus callosum dysgenesis, diffuse white matter volume loss, and hypoplastic vermis. In addition to NDD, we observed recurrent infections and death at toddler age. We further explored identified variants with cellular assays.

RESULTS: This clinical presentation overlaps with what was previously reported in two affected siblings with homozygous nonsense PI4K2A variant. Cellular studies analyzing these human variants confirmed their deleterious effect on PI4K2A activity and, together with the central role of PI4K2A in Rab7-associated vesicular trafficking, establish a link between late endosome-lysosome defects and NDD.

INTERPRETATION: Our study establishes the genotype-phenotype spectrum of PI4K-associated NDD and highlights several commonalities with other innate errors of intracellular trafficking.

PMID:35880319 | DOI:10.1002/acn3.51634

Immunol Res. 2022 Jul 25. doi: 10.1007/s12026-022-09310-y. Online ahead of print.

ABSTRACT

Hyper immunoglobulin M (HIGM) syndrome is a rare disorder of the immune system with impaired antibody functions. The clinical picture of the patients varies according to the underlying genetic variation. In this study, we identified two novel variants in AID and UNG genes, which are associated with autosomal recessive type HIGM, by targeted next-generation sequencing (NGS) panel. A biallelic 11 base pair deletion (c.278_288delATGTGGCCGAC) in the coding sequence of activation-induced cytidine deaminase (AID) gene was identified in a 36-year-old patient. Biallelic two base pair insertion in exon 7 of uracil nucleoside glycosylase (UNG) gene (c.924_925insGG) was identified in a 40-year-old patient. Both variants were confirmed by Sanger sequencing. HIGM, like many of the other primary immunodeficiencies, is a rare and difficult-to-diagnose entity with heterogeneous clinical phenotypes. It should be suspected in patients with a history of early-onset recurrent respiratory infections, enlarged lymph nodes, and autoimmune disorders. There might be a delay in diagnosis until adulthood especially in subtle cases or if HIGM is not included in the differential diagnosis due lacking of awareness. In this regard, genetic testing with NGS-based diagnostic panels provide a rapid and reasonable tool for the molecular diagnosis of patients with immunodeficiencies and hence, decrease the time to diagnose and prevent infection-related complications associated with increased morbidity and mortality.

PMID:35879489 | DOI:10.1007/s12026-022-09310-y

J Cardiovasc Dev Dis. 2022 Jul 5;9(7):216. doi: 10.3390/jcdd9070216.

ABSTRACT

Myocarditis is an inflammatory disease of the heart. Pediatric myocarditis with the dilated cardiomyopathy (DCM) phenotype may be caused by likely pathogenic or pathogenic genetic variants [(L)P] in cardiomyopathy (CMP) genes. Systematic analysis of immune disorder gene defects has not been performed so far. We analyzed 12 patients with biopsy-proven myocarditis and the DCM phenotype together with their parents using whole-exome sequencing (WES). The WES data were filtered for rare pathogenic variants in CMP (n = 89) and immune disorder genes (n = 631). Twelve children with a median age of 2.9 (1.0-6.8) years had a mean left ventricular ejection fraction of 28% (22-32%) and myocarditis was confirmed by endomyocardial biopsy. Patients with primary immunodeficiency were excluded from the study. Four patients underwent implantation of a ventricular assist device and subsequent heart transplantation. Genetic analysis of the 12 families revealed an (L)P variant in the CMP gene in 8/12 index patients explaining DCM. Screening of recessive immune disorder genes identified a heterozygous (L)P variant in 3/12 index patients. This study supports the genetic impact of CMP genes for pediatric myocarditis with the DCM phenotype. Piloting the idea that additional immune-related genetic defects promote myocarditis suggests that the presence of heterozygous variants in these genes needs further investigation. Altered cilium function might play an additional role in inducing inflammation in the context of CMP.

PMID:35877578 | DOI:10.3390/jcdd9070216

Front Immunol. 2022 Jul 8;13:883446. doi: 10.3389/fimmu.2022.883446. eCollection 2022.

ABSTRACT

To address inborn errors of immunity (IEI) which were underdiagnosed in resource-limited regions, our centre developed and offered free genetic testing for the most common IEI by Sanger sequencing (SS) since 2001. With the establishment of The Asian Primary Immunodeficiency (APID) Network in 2009, the awareness and definitive diagnosis of IEI were further improved with collaboration among centres caring for IEI patients from East and Southeast Asia. We also started to use whole exome sequencing (WES) for undiagnosed cases and further extended our collaboration with centres from South Asia and Africa. With the increased use of Next Generation Sequencing (NGS), we have shifted our diagnostic practice from SS to WES. However, SS was still one of the key diagnostic tools for IEI for the past two decades. Our centre has performed 2,024 IEI SS genetic tests, with in-house protocol designed specifically for 84 genes, in 1,376 patients with 744 identified to have disease-causing mutations (54.1%). The high diagnostic rate after just one round of targeted gene SS for each of the 5 common IEI (X-linked agammaglobulinemia (XLA) 77.4%, Wiskott-Aldrich syndrome (WAS) 69.2%, X-linked chronic granulomatous disease (XCGD) 59.5%, X-linked severe combined immunodeficiency (XSCID) 51.1%, and X-linked hyper-IgM syndrome (HIGM1) 58.1%) demonstrated targeted gene SS should remain the first-tier genetic test for the 5 common X-linked IEI.

PMID:35874699 | PMC:PMC9304939 | DOI:10.3389/fimmu.2022.883446

Caspian J Intern Med. 2022;13(Suppl 3):277-280. doi: 10.22088/cjim.13.0.277.

ABSTRACT

BACKGROUND: The most common causes of immunodeficiency are iatrogenic and the result of the widespread use of therapies which modulates the immune system, whether they are planned or haphazardly. Mucormycosis is an invasive fungal disease which is usually secondary to immunosuppression, diabetic ketoacidosis, and long-term use of antibiotics, corticosteroids, and cytotoxic drugs. There are researches which show patients with coronavirus disease 2019 (COVID-19), especially severely ill or immunocompromised, are more likely to suffer from invasive fungal infections. Patients with diabetes are at a higher risk for severe COVID-19 outcomes. However, there has been no clear evidence on the relationship between pre-diabetes state and mucormycosis as a complication of SARS-CoV-2 infection so far.

CASE PRESENTATION: Here, we report a case of sino-orbital mucormycosis in a pre-diabetic 54-year-old female without any underlying diseases. The patient suffered from COVID-19 pneumonia. She received 8 mg dexamethasone for 12 days. Afterwards, she returned three days after her discharge with a complaint of pre-orbital cellulitis, unilateral facial numbness and decreased visual acuity. Therefore, after primary diagnostic imaging, she was regarded as a candidate for invasive surgical intervention and was consequently treated with a combination of liposomal amphotericin B, radical recurrent surgery and posaconazole.

CONCLUSION: It is very important to consider patients who are in the pre-diabetic state or possibly immunocompromised before prescribing steroids. The patients should be examined for invasive fungal infections in post-discharge period.

PMID:35872692 | PMC:PMC9272951 | DOI:10.22088/cjim.13.0.277