UNASSIGNED: Prolidase deficiency is a rare multisystemic disease associated with collagen metabolism. Clinical manifestations and age of onset are highly variable. Prolidase deficiency is caused by homozygous variants in the PEPD gene. In this report, three siblings with c.1103T>G (L368R) variant in the PEPD gene are presented. They had features not described in the literature and marked intrafamilial clinical heterogeneity. This is the first family of Syrian ancestral origin with prolidase deficiency.
UNASSIGNED: We performed whole-exome sequencing for the index case, and detected a homozygous c.1103T>G variant, in the PEPD gene. All family members were then screened for the same variant by Sanger sequencing analysis. Two siblings were found to be homozygous, and one of them had not yet developed clinical symptoms.
UNASSIGNED: Our data expand the clinical spectrum of prolidase deficiency. It also improves our knowledge of phenotype and genotype relationships of prolidase deficiency patients.

The complement system, a vital component of innate immunity, consists of various proteins and pathways crucial for the recognition and elimination of pathogens. In addition, it plays a major role in the initiation of adaptive response through the opsonization of antigens, contributing to B-cell activation and memory maintenance. Deficiencies in complement proteins, particularly C3, can lead to severe and recurrent infections as well as immune complex disorders. Here, we present a case report of two siblings with total C3 deficiency resulting from compound heterozygous mutations in C3 (NM_000064.4): c.305dup; [p.Asn103GlnfsTer66] and c.1269 + 5G>T, previously unreported in C3-related diseases. Both, the index case and her sister, presented a history of recurrent infections since early childhood and one of them developed hemolytic uremic syndrome (HUS). Immunological evaluation revealed absent plasma C3 levels, decreased memory B cells, hypogammaglobulinemia, and impaired response to polysaccharide antigens. The siblings showed partial responses to antimicrobial prophylaxis and vaccination, requiring intravenous immunoglobulin replacement therapy, resulting in clinical improvement. Genetic analysis identified additional risk polymorphisms associated with atypical HUS. This case highlights the importance of comprehensive genetic and immunological evaluations in complement deficiencies, along with the potential role of immunoglobulin replacement therapy in managing associated antibody defects.

OBJECTIVE: Individuals with Down Syndrome (DS) exhibit a higher susceptibility to infections, suggesting potential immunological alterations within this population. Consequently, this study aims to assess the immune response profile in children with DS to identify potential immune dysfunctions associated with recurrent infections.
METHODS: The authors conducted a retrospective analysis involving 49 DS patients, examining various epidemiological, clinical, cytogenetic, and laboratory variables. The study\'s sample comprised patients aged 2-20 years, with a predominance of males. These patients were categorized into two groups based on the presence or absence of recurrent infections, as indicated by the Jeffrey Modell Foundation alert signs.
RESULTS: Immunoglobulin (Ig) A, G, and M levels were deemed normal, although individuals with DS experiencing recurrent infections exhibited significantly lower IgA levels. Additionally, CD3, CD4, CD8, and CD19 lymphocyte counts were found to be within normal ranges, with no significant differences between the two groups. While overall data indicated normal seroconversion levels of pneumococcal polysaccharide antibodies, a notable impairment in seroconversion was observed among DS patients with recurrent infections compared to those without such infections.
CONCLUSIONS: The deficiency of anti-polysaccharide antibodies in individuals with DS may constitute an important immunological comorbidity. Therefore, it warrants further investigation, particularly among individuals with recurrent infections.

The relationship between warts and hyper-immunoglobulin E (IgE) syndrome lies in the fact that patients with this syndrome may have recurrent or persistent skin warts because of their immune dysfunction. Therefore, it is important to consider this possibility when evaluating a patient with skin warts, especially if they are associated with other symptoms such as recurrent infections or pulmonary issues. Warts can thus be an important clinical sign indicating the presence of this syndrome. We report the case of a young girl presenting with numerous warts accompanied by pulmonary involvement and weight delay, in whom the diagnosis of hyper IgE syndrome was established.

UNASSIGNED: Extraintestinal Escherichia coli infections represent a growing public health threat, However, current studies often overlook important factors such as temporal patterns of infection, phylogenetic and clonal background, or the host gut E. coli population, despite their likely significance.
UNASSIGNED: In this study, we analyzed >7000 clinical E. coli isolates from patients at the Minneapolis Veterans Affairs Health Care System (2012-2019), and concurrent fecal E. coli from uninfected veterans. We assessed phylogenetic group distribution, membership in selected sequence types (STs), and subsets thereof-including the pandemic, resistance-associated ST131-H30R, and ST1193 lineages-and strain type, as defined by pulsed-field gel electrophoresis. We then analyzed these features alongside the temporal patterns of infection in individual hosts.
UNASSIGNED: The H30R lineage emerged as the leading lineage, both overall and among fluoroquinolone-resistant isolates, with ST1193 following among fluoroquinolone-resistant isolates. Recurrences were common, occurring in 31% of subjects and 41% of episodes, and often multiple and delayed/prolonged (up to 23 episodes per subject; up to 2655d post-index). Remarkably, these recurrences typically involved the subject\'s index strain (63% of recurrences), even when affecting extra-urinary sites. ST131, H30R, ST1193, and fluoroquinolone-resistant strains generally caused significantly more recurrences than did other strains, despite similar recurrence intervals. ST131 strain types shifted significantly over the study period. Infection-causing strains were commonly detectable in host feces at times other than during an infection episode; the likelihood of detection varied with surveillance intensity and proximity to the infection. H30R and ST1193 were prominent causes of fecal-clinical clonal overlap.
UNASSIGNED: These findings provide novel insights into the temporal and clonal characteristics of E. coli infections in veterans and support efforts to develop anti-colonization interventions.

ELF4 deficiency has been recently recognized as a novel disorder within the spectrum of inborn errors of immunity (IEIs), specifically categorized as a \"disease of immune dysregulation.\" Cases of this condition, reported by our team and others, are very limited worldwide. As such, our current knowledge of this new disease remains preliminary. This review aims to provide a brief overview of the clinical manifestations, pathogenesis, and treatment strategies for this novel IEI.
A comprehensive review was conducted after an extensive literature search in the PubMed/Medline database and websites concerning transcriptional factor ELF4 and reports concerning patients with ELF4 deficiency. Our search strategy was \"ELF4 OR ETS-related transcription factor Elf-4 OR EL4-like factor 4 OR myeloid Elf-1-like factor\" as of the time of manuscript submission.
The current signature manifestations of ELF4 deficiency disorder are recurrent and prolonged oral ulcer, abdominal pain, and diarrhea in pediatric males. In some cases, immunodeficiency and autoimmunity can also be prominent. Targeted Sanger sequencing or whole exome sequencing can be used to detect variation in ELF4 gene. Western blotting for ELF4 expression of the patient\'s cells can confirm the pathogenic effect of the variant. To fully confirm the pathogenicity of the variant, further functional test is strongly advised. Glucocorticoid and biologics are the mainstream management of ELF4 deficiency disorder.
Pediatric males presenting with recurring ulcerations in digestive tract epithelium with or without recurrent fever should be suspected of DEX. When atypical presentations are prominent, variations in ELF4 gene should be carefully evaluated functionally due to the complex nature of ELF4 function. Experience of treating DEX includes use of glucocorticoid and biologics and more precise treatment needs more patients to identify and further mechanistic study.

Toll-like receptors (TLRs) play an important role in innate immunity. Previous studies have shown that single nucleotide polymorphisms (SNPs) in the genes coding for these innate immune molecules can affect susceptibility to and the outcome of certain diseases. The aim of the present study was to examine the clinical relevance of well-studied TLR1-4 SNPs in individuals who are prone to infections. Four functional SNPs, TLR1 rs5743618 (1805C > A, Ser602Ile), TLR2 rs5743708 (2258G > A, Arg753Gln), TLR3 rs3775291 (1234C > T, Leu412Phe) and TLR4 rs4986790 (896A > G, Asp299Gly), were analysed in 155 patients with recurrent respiratory infections (n = 84), severe infections (n = 15) or common variable immunodeficiency (n = 56), and in 262 healthy controls, using the High Resolution Melting Analysis method. Polymorphisms of TLR2 rs5743708 (odds ratio [OR] 3.16; 95% confidence interval [CI] 1.45-6.83, p = .004, ap = .016) and TLR4 rs4986790 (OR 1.8; 95% CI 1.05-3.12, p = .028, ap = .112) were more frequent in patients with recurrent or severe infections than in controls. Interestingly, seven patients were found to carry both variant genotypes of TLR2 and TLR4, whereas none of the control group carried such genotypes (p  ≤ .0001). Moreover, TLR2 polymorphism was associated with increased risk for acute otitis media episodes (OR, 3.02; 95% CI 1.41-6.47; p = .012). This study indicates that children and adults who are more prone to recurrent or severe respiratory infections carry one or both variant types of TLR2 and TLR4 more often than control subjects. Genetic variations of TLRs help explain why some children are more susceptible to respiratory infections.

Kabuki Syndrome (KS) is a multisystemic genetic disorder. A portion of patients has immunological manifestations characterized by increased susceptibility to infections and autoimmunity. Aiming to describe the clinical and laboratory immunological aspects of KS, we conducted a retrospective multicenter observational study on patients with KS treated in centers affiliated to the Italian Primary Immunodeficiency Network.Thirty-nine patients were enrolled, with a median age at evaluation of 10 years (range: 3 m-21y). All individuals had organ malformations of variable severity. Congenital heart defect (CHD) was present in 19/39 patients (49%) and required surgical correction in 9/39 (23%), with associated thymectomy in 7/39 (18%). Autoimmune cytopenia occurred in 6/39 patients (15%) and was significantly correlated with thymectomy (p < 0.002), but not CHD. Individuals with cytopenia treated with mycophenolate as long-term immunomodulatory treatment (n = 4) showed complete response. Increased susceptibility to infections was observed in 22/32 patients (69%). IgG, IgA, and IgM were low in 13/29 (45%), 13/30 (43%) and 4/29 (14%) patients, respectively. Immunoglobulin substitution was required in three patients. Lymphocyte subsets were normal in all patients except for reduced naïve T-cells in 3/15 patients (20%) and reduced memory switched B-cells in 3/17 patients (18%). Elevated CD3 + TCRαβ + CD4-CD8-T-cells were present in 5/17 individuals (23%) and were correlated with hematological and overall autoimmunity (p < 0.05).In conclusion, immunological manifestations of KS in our cohort include susceptibility to infections, antibody deficiency, and autoimmunity. Autoimmune cytopenia is correlated with thymectomy and elevated CD3 + TCRαβ + CD4-CD8-T-cells, and benefits from treatment with mycophenolate.

Good Syndrome is a rare disease that comprises the presence of a thymoma, immunodeficiency, and recurrent opportunistic infections. We report the case of a young woman who was diagnosed with Good Syndrome, who had a long-term history of recurrent infections, often due to atypical agents, and who also had a previous history of immunodeficiency and a B1 thymoma invading the large vessels, lung, and pericardium (Masaoka stage IV). She underwent surgical resection of the mediastinal mass, requiring vena cava superior reconstruction due to the extent of invasion, followed by adjuvant radiotherapy and immunoglobulin G supplementation. Despite relative stability in the subsequent years, without serious infections, after three years she had a thymoma recurrence requiring a new therapeutic approach. This case highlights the importance of a thorough investigation of the underlying causes of recurrent infections, which may be the result of an immunodeficiency secondary to malignancy. In young patients, early diagnosis is crucial to avoid disease progression and to reduce mortality rates. To achieve such outcomes, a multidisciplinary team and a comprehensive therapeutic strategy are necessary.

Retained needle fragments commonly serve as sources of recurrent infections with a potential to embolize to the heart and lungs and can lead to life-threatening consequences. Here, we report a case of a 46-year-old male with a history of intravenous drug user and chronic forearm wounds, presenting with sepsis. Several retained needles are identified on CT scan, several days postadmission. This case highlights the importance of timely assessment of infectious sources in patients with history of intravenous drug abuse.