Melanoma-like features in pediatric longitudinal melanonychia: A systematic review and meta-analysis.

BACKGROUND: Pediatric longitudinal melanonychia (LM) can exhibit atypical features that mimic red-flag signs for subungual melanoma in adults and lead to diagnostic uncertainty. Nail biopsy may be unnecessary if clinical inspection and dermoscopy suggest a benign nature. METHODS: We searched PubMed and Embase from inception to February 2023 for studies of any design reporting either the number or proportion of clinical and dermoscopic features in at least five children (≤18 years) with LM. Non-English articles, reviews, and abstracts were excluded. We performed a systematic review and meta-analysis to collate all existing data. RESULTS: A total of 1218 articles were screened and 24 studies with 1391 pediatric patients were included. Nevus was the most common diagnosis (86.3%). The most prevalent sites were fingernails (76.2%) and first digits (45.4%). Pooled proportions of common features were: dark-color bands (69.8%), multi-colored bands (47.6%), broad bandwidth (41.1%), pseudo-Hutchinson sign (41.0%), irregular patterns (38.1%), Hutchinson sign (23.7%), dots and globules (22.5%), nail dystrophy (18.2%), and triangular sign (10.9%). Outcomes included progression (widening or darkening, 29.9%), stability (23.3%), and spontaneous regression (narrowing or fading, 19.9%). Only eight cases of subungual melanoma in situ were reported, and no invasive melanomas were identified. CONCLUSION: Although atypical characteristics are common in pediatric LM, the probability of malignant transformation is exceedingly low. Appropriate evaluation and management of pediatric LM includes careful clinical and dermoscopic inspection with attention to benign features followed by long-term interval follow-up.

Recessive Mutations in AP1B1 Cause Ichthyosis, Deafness, and Photophobia.

We describe unrelated individuals with ichthyosis, failure to thrive, thrombocytopenia, photophobia, and progressive hearing loss. Each have bi-allelic mutations in AP1B1, the gene encoding the ß subunit of heterotetrameric adaptor protein 1 (AP-1) complexes, which mediate endomembrane polarization, sorting, and transport. In affected keratinocytes the AP-1 ß subunit is lost, and the γ subunit is greatly reduced, demonstrating destabilization of the AP-1 complex. Affected cells and tissue contain an abundance of abnormal vesicles and show hyperproliferation, abnormal epidermal differentiation, and derangement of intercellular junction proteins. Transduction of affected cells with wild-type AP1B1 rescues the vesicular phenotype, conclusively establishing that loss of AP1B1 function causes this disorder.

Inflammatory linear verrucous epidermal nevus (ILVEN) encompasses a spectrum of inflammatory mosaic disorders.

BACKGROUND: Inflammatory linear verrucous epidermal nevus (ILVEN) is a rare skin disease characterized by pruritic erythematous scaly plaques distributed along the lines of Blaschko. Two cases of ILVEN with CARD14 mutations and one case with a GJA1 mutation have been previously reported. OBJECTIVE: To elucidate the genetic cause of a cohort of patients diagnosed based on clinical and histopathological evaluation with ILVEN. METHODS: We recruited patients diagnosed with ILVEN based on clinical and histopathological criteria. Exome sequencing of affected skin with or without blood/saliva was performed and germline and somatic pathogenic variants were identified. RESULTS: Five patients were enrolled. All had skin lesions from birth or early childhood. Two patients developed psoriasis vulgaris after the diagnosis of ILVEN. The first had a germline heterozygous CARD14 mutation and a post-zygotic hotspot mutation in KRT10. The histopathologic evaluation did not show epidermolytic hyperkeratosis. The second had a post-zygotic hotspot mutation in HRAS. Her ILVEN became itchy once psoriasis developed. One patient was re-diagnosed with linear porokeratosis based on a germline mutation in PMVK and a post-zygotic second-hit mutation. Two patients were re-diagnosed with congenital hemidysplasia with ichthyosiform nevus and limb defect nevus based on germline NSDHL mutations. CONCLUSION: ILVEN is a clinical descriptor for a heterogenous group of mosaic inflammatory disorders. Genetic analysis has the potential to more precisely categorize ILVEN and permits pathogenesis-directed therapies in some cases.

JAK Inhibitors for the Treatment of Pediatric Alopecia Areata.

Alopecia areata is a common autoimmune condition that disproportionately affects children and can significantly hinder quality of life. Few safe and effective therapies are available for the treatment of severely affected pediatric patients. JAK inhibitors have been recently established as an effective and well-tolerated therapy in adults, but there are limited data regarding the use of JAK inhibitors to treat alopecia areata in children. Here, we review the available literature regarding the use of JAK inhibitors in children in dermatology and across other medical disciplines.

Topical cholesterol/lovastatin for the treatment of porokeratosis: A pathogenesis-directed therapy.

BACKGROUND: Porokeratosis is associated with mevalonate pathway gene mutations. Therapeutic options are few and often limited in efficacy. We hypothesized that topical therapy that aims to replenish cholesterol, an essential mevalonate pathway end-product, and block the accumulation of mevalonate pathway toxic metabolites could alleviate porokeratosis. OBJECTIVE: To study the efficacy of topical cholesterol/lovastatin in different variants of porokeratosis. METHODS: We enrolled a series of 5 porokeratosis patients,1 with disseminated superficial actinic porokeratosis, 2 with porokeratosis palmaris et plantaris disseminata, and 2 with linear porokeratosis. Patients were genotyped before initiation of therapy. Patients then applied topical cholesterol/lovastatin twice daily to a unilaterally defined treatment area for up to 3 months. The response was evaluated and patients photographed at every visit. RESULTS: Three patients had MVD mutations, and 2 patients had PMVK mutations. Treatment with topical cholesterol/lovastatin (but not cholesterol alone) resulted in near complete clearance of disseminated superficial actinic porokeratosis lesions after 4 weeks of therapy and moderate improvement of porokeratosis palmaris et plantaris disseminata lesions and linear porokeratosis lesions. There were no adverse events. LIMITATIONS: Case series design with a small number of patients. CONCLUSION: Topical cholesterol/lovastatin is an effective and well-tolerated therapy for porokeratosis that underscores the utility of a pathogenesis-based therapy that replaces deficient end products and prevents accumulation of potentially toxic precursors.

Epitranscriptomic profiling across cell types reveals associations between APOBEC1-mediated RNA editing, gene expression outcomes, and cellular function.

Epitranscriptomics refers to posttranscriptional alterations on an mRNA sequence that are dynamic and reproducible, and affect gene expression in a similar way to epigenetic modifications. However, the functional relevance of those modifications for the transcript, the cell, and the organism remain poorly understood. Here, we focus on RNA editing and show that Apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-1 (APOBEC1), together with its cofactor RBM47, mediates robust editing in different tissues. The majority of editing events alter the sequence of the 3'UTR of targeted transcripts, and we focus on one cell type (monocytes) and on a small set of highly edited transcripts within it to show that editing alters gene expression by modulating translation (but not RNA stability or localization). We further show that specific cellular processes (phagocytosis and transendothelial migration) are enriched for transcripts that are targets of editing and that editing alters their function. Finally, we survey bone marrow progenitors and demonstrate that common monocyte progenitor cells express high levels of APOBEC1 and are susceptible to loss of the editing enzyme. Overall, APOBEC1-mediated transcriptome diversification is required for the fine-tuning of protein expression in monocytes, suggesting an epitranscriptomic mechanism for the proper maintenance of homeostasis in innate immune cells.

Ileitis associated with Meckel's diverticulum.

AIMS: Histological features of chronic active ileitis in the small intestine neighbouring a Meckel's diverticulum raise the possibility of concurrent Crohn's disease. Several studies have reported a significant association between Meckel's diverticulum and Crohn's disease, whereas some case reports have proposed that the ileitis is attributable to acid-secreting gastric heterotopia. The aim of this study was to evaluate the incidence, histomorphology and clinical follow-up of Meckel's diverticulum-associated ileitis. METHODS AND RESULTS: Medical records and slides from 48 consecutive surgical resections performed for Meckel's diverticulum were reviewed. Nine of 48 adults had significant inflammatory changes in the small intestine neighbouring the diverticulum. Two were transmural ulcers attributable to ingestion of a sharp object. Two patients had established Crohn's disease, both with long segments (>95 mm) of transmural inflammation located >100 mm from the diverticulum. The remaining five patients had inflammatory changes (ulceration, pseudopyloric metaplasia, submucosal fibrosis, and muscularis mucosa hyperplasia) confined to a short segment (<20 mm) of mucosa/submucosa within 50-60 mm of the diverticulum. Two had gastric heterotopia in the diverticulum. None of these five patients used non-steroidal anti-inflammatory drugs (NSAIDs). On follow-up, none had symptoms, imaging or pathology suggestive of Crohn's disease. CONCLUSIONS: Ileitis affecting a short segment of mucosa and submucosa in the small intestine near a Meckel's diverticulum is relatively common, and is not necessarily related to Crohn's disease.

A Quality Improvement Initiative to Reduce Necrotizing Enterocolitis in Very Preterm Infants.

OBJECTIVE: To reduce the incidence of necrotizing enterocolitis (NEC) among very preterm infants in the Calgary Health Region to ≤2% within 2 years. METHODS: A multidisciplinary team developed key drivers for NEC. Targeted interventions included strategies to increase mothers' own milk (MOM), improve compliance with feeding regimens, standardize management of feeding intolerance, prevent intestinal microbial aberrations, and feed conservatively during blood transfusion and the treatment of patent ductus arteriosus. The outcome measure was NEC (≥ stage 2). Changes in NEC rates were examined among racial and ethnic groups. Process measures included MOM feeding at discharge, the difference between actual and expected time to reach full feeds, lowest hemoglobin, and the duration of empirical antibiotics. Growth, the rate of blood transfusion, and the duration of parenteral nutrition were balancing measures. The preintervention, intervention, and sustainment periods were January 2013 to June 2016, July 2016 to December 2018, and December 2018 to December 2021, respectively. RESULTS: We included 2787 infants born at ≤326/7 weeks' gestation (1105 preintervention, 763 during intervention, and 919 in sustainment). NEC decreased from 5.6% to 1.9%. Process measures indicated increased MOM feeding at discharge, improved compliance with feeding regimens, increased lowest hemoglobin levels, and shorter durations of empirical antibiotics. Balancing measures revealed improved weight Z-scores, shorter durations on parenteral nutrition, and increased rates of blood transfusion. CONCLUSIONS: Quality improvement initiatives to increase MOM, improve compliance with feeding regimens, feed conservatively during blood transfusion and treatment of patent ductus arteriosus, and prevent intestinal microbial aberrations were associated with reduced NEC.

Antimicrobial Stewardship at Birth in Preterm Infants: Not Just About a Decrease!

BACKGROUND: Early-onset sepsis results in increased morbidity and mortality in preterm infants. Antimicrobial Stewardship Programs (ASPs) address the need to balance adverse effects of antibiotic exposure with the need for empiric treatment for infants at the highest risk for early-onset sepsis. METHODS: All preterm infants <34 weeks gestational age born during a 6-month period before (January 2017-June 2017) and a 6-month period after (January 2019-June 2019) implementation of ASP in May 2018 were reviewed. The presence of perinatal sepsis risk factors, eligibility for, versus treatment with initial empiric antibiotics was compared. RESULTS: Our cohort comprised 479 infants with a mean of 30 weeks gestation and birth weight of 1400 g. Demographics were comparable, with more Cesarean section deliveries in the post-ASP cohort. Any sepsis risk factor was present in 73.6% versus 68.4% in the pre- versus post-ASP cohorts (P = 0.23). Fewer infants were treated with antibiotics in the later cohort (60.4%) compared with the earlier cohort (69.7%; P = 0.04). Despite the presence of risk factors (preterm labor in 93% and rupture of membranes in 60%), 42% of infants did not receive initial antibiotics. Twenty percent with no perinatal sepsis risk factors were deemed low-risk and not treated. CONCLUSIONS: Implementation of a neonatal ASP decreased antibiotic initiation at birth. Antibiotic use decreased (appropriately) in the subgroup with no perinatal sepsis risk factors. Of concern, some infants were not treated despite risk factors, such as preterm labor/rupture of membrane. Neonatal ASP teams need to be aware of potentially unintended consequences of their initiatives.

NLRP3 Inflammasome Priming and Activation Are Regulated by a Phosphatidylinositol-Dependent Mechanism.

Imbalance in lipid homeostasis is associated with discrepancies in immune signaling and is tightly linked to metabolic disorders. The diverse ways in which lipids impact immune signaling, however, remain ambiguous. The phospholipid phosphatidylinositol (PI), which is implicated in numerous immune disorders, is chiefly defined by its phosphorylation status. By contrast, the significance of the two fatty acid chains attached to the PI remains unknown. In this study, by using a mass spectrometry-based assay, we demonstrate a role for PI acyl group chains in regulating both the priming and activation steps of the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome in mouse macrophages. In response to NLRP3 stimuli, cells deficient in ABC transporter ATP Binding Cassette Subfamily B Member 1 (ABCB1), which effluxes lipid derivatives, revealed defective inflammasome activation. Mechanistically, Abcb1 deficiency shifted the total PI configuration exhibiting a reduced ratio of short-chain to long-chain PI acyl lipids. Consequently, Abcb1 deficiency initiated the rapid degradation of Toll/IL-1R domain-containing adaptor protein, the TLR adaptor protein that binds PI (4,5)-bisphosphate, resulting in defective TLR-dependent signaling, and thus NLRP3 expression. Moreover, this accompanied increased NLRP3 phosphorylation at the Ser291 position and contributed to blunted inflammasome activation. Exogenously supplementing wild-type cells with linoleic acid (LA), but not arachidonic acid, reconfigured PI acyl chains. Accordingly, LA supplementation increased Toll/IL-1R domain-containing adaptor protein degradation, elevated NLRP3 phosphorylation, and abrogated inflammasome activation. Furthermore, NLRP3 Ser291 phosphorylation was dependent on PGE2-induced protein kinase A signaling because pharmacological inhibition of this pathway in LA-enriched cells dephosphorylated NLRP3. Altogether, our study reveals, to our knowledge, a novel metabolic-inflammatory circuit that contributes to calibrating immune responses.

Molecular and Clinical Outcomes After Intravenous Gentamicin Treatment for Patients With Junctional Epidermolysis Bullosa Caused by Nonsense Variants.

IMPORTANCE: Junctional epidermolysis bullosa (JEB) is an incurable blistering skin disorder with high infant mortality often caused by nonsense variants in the genes that encode laminin 332. OBJECTIVE: To evaluate the safety and outcomes following intravenous gentamicin readthrough therapy and subsequent laminin 332 expression in patients with JEB. DESIGN, SETTING, AND PARTICIPANTS: This open-label, pilot nonrandomized clinical trial assessed 1 course of low- or high-dose intravenous gentamicin, including follow-up at 30 and 90 days after treatment. Five pediatric patients with JEB (2 with intermediate JEB and 3 with severe JEB) and confirmed nonsense variants in LAMA3 or LAMB3 in 1 or 2 alleles and decreased expression of laminin 332 at the dermal-epidermal junction of their skin participated in the study, which was performed at a single institution in collaboration with physicians and home infusion services near the patients from April 1, 2019, to February 28, 2021, with follow-up until May 31, 2021. INTERVENTIONS: Three patients received gentamicin at 7.5 mg/kg daily for 14 days, and 2 patients received gentamicin at 10 mg/kg daily for 24 days. MAIN OUTCOMES AND MEASURES: Primary outcomes were change in expression of laminin 332 in patients' skin and assessments for safety (ototoxic effects, nephrotoxic effects, and autoimmune response). Secondary outcomes included wound healing in monitored wounds and Epidermolysis Bullosa Disease Activity and Scarring Index (EBDASI) score. RESULTS: After gentamicin treatment, all 5 patients (age range, 3 months to 10 years, 4 [80%] female) exhibited increased laminin 332 in the dermal-epidermal junction. By 1 month, 7 of 9 wounds in patients receiving low-dose intravenous gentamicin and all wounds in patients receiving high-dose intravenous gentamicin exhibited at least 50% wound closure. By 3 months, 8 of 9 wounds in patients receiving low-dose gentamicin and all wounds in patients receiving high-dose intravenous gentamicin exhibited greater than 85% closure. All 3 patients who were evaluated with EBDASI showed a decrease in total activity scores that met minimal clinically important differences 1 month after treatment. All 5 patients completed the study, and no ototoxic effects, nephrotoxic effects, or anti-laminin 332 antibodies were detected. CONCLUSIONS AND RELEVANCE: In this nonrandomized clinical trial, intravenous gentamicin therapy was associated with induced readthrough of nonsense variants in patients with JEB, restored functional laminin 332 in their skin, and wound closure during the 3-month study period. Although long-term safety and efficacy requires further evaluation, a single cycle of intravenous gentamicin may be a safe and readily available therapy in the short term for this population of patients with JEB. TRIAL REGISTRATION: ClinicalTrials.gov Identifiers: NCT03526159 and NCT04140786.

SHP-2 activates signaling of the nuclear factor of activated T cells to promote skeletal muscle growth.

The formation of multinucleated myofibers is essential for the growth of skeletal muscle. The nuclear factor of activated T cells (NFAT) promotes skeletal muscle growth. How NFAT responds to changes in extracellular cues to regulate skeletal muscle growth remains to be fully defined. In this study, we demonstrate that mice containing a skeletal muscle-specific deletion of the tyrosine phosphatase SHP-2 (muscle creatine kinase [MCK]-SHP-2 null) exhibited a reduction in both myofiber size and type I slow myofiber number. We found that interleukin-4, an NFAT-regulated cytokine known to stimulate myofiber growth, was reduced in its expression in skeletal muscles of MCK-SHP-2-null mice. When SHP-2 was deleted during the differentiation of primary myoblasts, NFAT transcriptional activity and myotube multinucleation were impaired. Finally, SHP-2 coupled myotube multinucleation to an integrin-dependent pathway and activated NFAT by stimulating c-Src. Thus, SHP-2 transduces extracellular matrix stimuli to intracellular signaling pathways to promote skeletal muscle growth.

Diverse functions for DNA and RNA editing in the immune system.

Polynucleotide DNA and RNA editing enzymes alter nucleic acid sequences and can thereby modify encoded informational content. Two major families of polynucleotide editing enzymes, the AID/APOBEC cytidine deaminases (which catalyze the deamination of cytidine to uridine) and the adenosine deaminases acting on RNA (ADARs, which catalyze the deamination of adenosine to inosine), function in a variety of host defense mechanisms. These enzymes act in innate and adaptive immune pathways, with both host and pathogen targets. DNA editing by the cytidine deaminase AID mediates immunoglobulin somatic hypermutation and class switch recombination, providing the antibody response with the flexibility and diversity to defend against an almost limitless array of varied and rapidly adapting pathogenic challenges. Other cytidine deaminases (APOBEC3) restrict retroviral infection by editing viral retrogenomes. Adenosine deaminases (ADARs) shape innate immune responses by modifying host transcripts that encode immune effectors and their regulators. Here we review current knowledge of polynucleotide DNA and RNA editors with a focus on these and other functions they serve in the immune system.

Attachment stability and the emergence of unresolved representations during adolescence.

This 15-year longitudinal study examined the stability of attachment representations from infancy to adolescence and investigated the emergence of unresolved representations during adolescence in a sample of 47 16-year-olds. Attachment was assessed at 12 months using the Strange Situation Procedure, at 4 years using the modified Strange Situation Procedure, and again at 16 years with the Adult Attachment Projective (AAP). The emergence of unresolved classifications in adolescence (AAP) was associated with higher rates of negative life events, low levels of early mother-child relationship security (an aggregate measure of the 12-month and 4-year measures), negative teacher-child relationship experiences in middle childhood, and low early adolescent friendship quality. The results support the growing body of evidence suggesting that changes in attachment are lawful, while adding to the growing understanding of the emergence of unresolved attachment representations.

Right place, right time: localisation and assembly of the NLRP3 inflammasome.

The NLRP3 inflammasome is a multimeric protein complex that cleaves caspase-1 and the pro-inflammatory cytokines interleukin 1 beta (IL-1ß) and IL-18. Dysregulated NLRP3 inflammasome signalling is linked to several chronic inflammatory and autoimmune conditions; thus, understanding the activation mechanisms of the NLRP3 inflammasome is essential. Studies over the past few years have implicated vital roles for distinct intracellular organelles in both the localisation and assembly of the NLRP3 inflammasome. However, conflicting reports exist. Prior to its activation, NLRP3 has been shown to be resident in the endoplasmic reticulum (ER) and cytosol, although, upon activation, the NLRP3 inflammasome has been shown to assemble in the cytosol, mitochondria, and mitochondria-associated ER membranes by different reports. Finally, very recent work has suggested that NLRP3 may be localised on or adjacent to the Golgi apparatus and that release of mediators from this organelle may contribute to inflammasome assembly. Therefore, NLRP3 may be strategically placed on or in close proximity to these subcellular compartments to both sense danger signals originating from these organelles and use the compartment as a scaffold to assemble the complex. Understanding where and when NLRP3 inflammasome assembly occurs may help identify potential targets for treatment of NLRP3-related disorders.

Glutamatergic calcium dynamics and deregulation of rat retinal ganglion cells.

A rise in intracellular calcium levels ([Ca(2+)](i)) is a key trigger for the lethal effects of the excitatory neurotransmitter glutamate in various central neurons, but a consensus has not been reached on the pathways that mediate glutamate-dependent increases of [Ca(2+)](i) in retinal ganglion cells (RGCs). Using Ca(2+) imaging techniques we demonstrated that, in the absence of external Mg(2+), the Ca(2+) signal evoked by glutamate was predominantly mediated by NMDA-type glutamate receptors (NMDA-Rs) in immunopanned RGCs isolated from neonatal or adult rats. Voltage-gated Ca(2+) channels and AMPA/kainate-Rs contributed a smaller portion of the Ca(2+) response at saturating concentrations of glutamate. Consistent with NMDA-R involvement, extracellular Mg(2+) inhibited RGC glutamate responses, while glycine had a potentiating effect. With Mg(2+) present externally, the effect of AMPA/kainate-R antagonists was enhanced and both NMDA- and AMPA/kainate-R antagonists greatly reduced the glutamate-induced increases of RGC [Ca(2+)](i). This finding indicates that the primary contribution of AMPA/kainate-Rs to RGC glutamatergic Ca(2+) dynamics is through the depolarization-dependent relief of the Mg(2+) block of NMDA-R channels. The effect of glutamate receptor antagonists on glutamatergic Ca(2+) signals from RGCs in adult rat retinal wholemounts yielded results similar to those obtained using immunopanned RGCs. Additional experiments on isolated RGCs revealed that during a 1 h glutamate (10-1000 microm) exposure, 18-28% of RGCs exhibited delayed Ca(2+) deregulation (DCD) and the RGCs that underwent DCD were positive for the death marker annexin V. RGCs with larger glutamate-evoked Ca(2+) signals were more likely to undergo DCD, and NMDA-R blockade significantly reduced the occurrence of DCD. Identifying the mechanisms underlying RGC excitotoxicity aids in our understanding of the pathophysiology of retinal ischaemia, and this work establishes a major role for NMDA-R-mediated increases in [Ca(2+)](i) in glutamate-related RGC death.

Trafficking of cholesterol to the ER is required for NLRP3 inflammasome activation.

Cellular lipids determine membrane integrity and fluidity and are being increasingly recognized to influence immune responses. Cellular cholesterol requirements are fulfilled through biosynthesis and uptake programs. In an intricate pathway involving the lysosomal cholesterol transporter NPC1, the sterol gets unequally distributed across intracellular compartments. By using pharmacological and genetic approaches targeting NPC1, we reveal that blockade of cholesterol trafficking through the late endosome-lysosome pathway blunts NLRP3 inflammasome activation. Altered cholesterol localization at the plasma membrane (PM) in Npc1-/- cells abrogated AKT-mTOR signaling by TLR4. However, the inability to activate the NLRP3 inflammasome was traced to perturbed cholesterol trafficking to the ER but not the PM. Accordingly, acute cholesterol depletion in the ER membranes by statins abrogated casp-1 activation and IL-1ß secretion and ablated NLRP3 inflammasome assembly. By contrast, assembly and activation of the AIM2 inflammasome progressed unrestricted. Together, this study reveals ER sterol levels as a metabolic rheostat for the activation of the NLRP3 inflammasome.

Immunity to uropathogens: the emerging roles of inflammasomes.

Urinary tract infections (UTIs) cause a huge burden of morbidity worldwide with recurrent UTIs becoming increasingly frequent owing to the emergence of antibiotic-resistant bacterial strains. Interactions between the innate and adaptive immune responses to pathogens colonizing the urinary tract have been the focus of much research. Inflammasomes are part of the innate immune defence and can respond rapidly to infectious insult. Assembly of the multiprotein inflammasome complex activates caspase-1, processes proinflammatory cytokines IL-1ß and IL-18, and induces pyroptosis. These effector pathways, in turn, act at different levels to either prevent or resolve infection, or eliminate the infectious agent itself. In certain instances, inflammasome activation promotes tissue pathology; however, the precise functions of inflammasomes in UTIs remain unexplored. An improved understanding of inflammasomes could provide novel approaches for the design of diagnostics and therapeutics for complicated UTIs, enabling us to overcome the challenge of drug resistance.