Chromosome 22q11.2 deletion syndrome (22q11DS) presents a wide variability of phenotypic features, including different grades of immune dysfunctions, leading to increased susceptibility to infections, autoimmune diseases and atopy. The most common autoimmune manifestation in 22q11DS patients is immune thrombocytopenia (ITP), which is often relapsing and refractory to standard therapy.

Neonatal dengue is an underrecognized infection that can mimic neonatal sepsis, leading to diagnostic challenges, particularly in endemic regions and in the context of perinatal or household exposure. We report the case of a term male neonate, delivered by emergency cesarean section for abruptio placenta, who developed early respiratory distress, thrombocytopenia, and petechial rash shortly after birth. Initial management included respiratory support and empirical antibiotics for suspected sepsis; however, bacterial cultures remained negative. Dengue infection was confirmed by polymerase chain reaction and IgM serology in both the mother and the neonate. The infant improved with supportive care and had complete clinical and hematological recovery on follow-up. This case highlights the importance of considering dengue in neonates presenting with sepsis-like features to enable timely diagnosis, avoid unnecessary antibiotic exposure, and ensure appropriate monitoring for potential complications.

Henoch-Schönlein purpura (HSP) is an inflammatory condition affecting the small blood vessels, leading to organ damage and symptoms across various body systems, including skin, joints, and kidneys. The disease's pathogenesis involves the deposition of immunoglobulin (Ig) A immune complexes in vessels, triggering inflammation and damage. Recent research highlights the role of T follicular helper cells (Tfh cells) in HSP. The review delves into Tfh cells' biological functions, emphasizing their involvement in the HSP's development by activating autoreactive B cells and inducing the production of autoantibodies through the secretion of interleukin (IL)-21, IL-4, and IL-6. Additionally, the roles of different Tfh cell subsets in the pathogenesis of HSP are also characterized by their unique features. We also highlight the relationship between Tfh cells and galactose-deficient IgA1 (Gd-IgA1) production, compare Tfh-mediated immune responses in HSP with those in IgA nephropathy (IgAN) and systemic lupus erythematosus (SLE), and discuss emerging therapeutic strategies targeting the Tfh-B-cell axis. It concludes by suggesting the need for further research on Tfh cells to understand HSP pathogenesis better and develop effective treatments.

Evans syndrome (ES) is a rare autoimmune disorder characterized by autoimmune hemolytic anemia and immune thrombocytopenic purpura, conferring an increased risk of postoperative bleeding, thrombosis, and infection. Limited guidance for perioperative management is available for patients with ES undergoing free flap reconstruction.

Ethylmalonic (EMA) and methylsuccinic (MSA) acids concentrations are elevated in tissues and body fluids of patients with ethylmalonic encephalopathy (EE), a mitochondrial disorder associated with basal ganglia abnormalities. To clarify the pathophysiology of this disorder, we evaluated the effects of EMA and MSA on bioenergetics, redox homeostasis and mitochondrial permeability transition (MPT) in rat striatum. We verified that EMA and MSA reduced state 3 and uncoupled respiration and inhibited the activities of α-ketoglutarate dehydrogenase and complex IV of the electron transport chain. Both organic acids also decreased mitochondrial membrane potential and Ca[2+] retention capacity, which were normalized by cyclosporine A and ADP, indicating induction of MPT pore opening. These effects were further mitigated by N-ethylmaleimide and dithiothreitol, suggesting that thiol groups of the MPT pore were oxidized by EMA and MSA. Moreover, EMA and MSA mildly decreased reduced glutathione concentrations, reinforcing that thiol group are oxidized by these organic acids. Therefore, it is presumed that EMA- and MSA-induced bioenergetic impairment associated with MPT pore opening is involved in the pathophysiology of basal ganglia injury observed in EE.

Background. Acquired platelet dysfunction with eosinophilia (APDE) is a transient bleeding disorder initially thought to occur exclusively in Southeast Asia. There are no uniformly agreed diagnostic criteria, and its full clinical features have not been defined. Methods. A literature search was conducted through MEDLINE, EMBASE, and Google Scholar for publications on APDE in order to explore patient demography, epidemiology, diagnostic criteria, and laboratory findings of the disease. Results. Ten retrospective, observational studies, five case series, and 21 case reports were identified with a total of 431 patients. Diagnostic criteria varied, with a two-tier approach for the diagnosis of impaired platelet function. In recent years, cases of APDE have been reported extensively outside of the Malay peninsula. Male patients (243/390, 62.3%) predominated. Their ages ranged from 11 months to 30 years, with only 40 (9.3%) subjects aged 18 years or older. Eosinophilia was absent in 10 to 33% of subjects in a few observational studies. Thrombocytopenia was present in 42 (9.7%) subjects. Parasitic infestation was less common in the new millennium. Spontaneous recovery within six months was the trend, and serious complications were extremely rare. Conclusions. APDE is no longer restricted to Southeast Asia. A uniform set of diagnostic criteria is needed. Clinician awareness followed by reliable but easily available laboratory tests is essential to confirm diagnosis. It is proposed that rapid diagnosis can be accomplished by screening the blood smear for grey platelets by a trained examiner followed by confirmatory platelet aggregometry. National or international collaboration and prospective studies are required to delineate the core and variable clinical and laboratory features of APDE.

Background Thrombocytopenia is a common hematological disorder encountered in clinical practice. To improve diagnostic efficiency and patient outcomes, it is important to understand its frequent clinical manifestations and predominant etiologies in different healthcare settings. This study aimed to describe the typical clinical presentations and underlying causes of thrombocytopenia among patients at a tertiary care hospital in the Kingdom of Saudi Arabia. Study design A single-center, retrospective cross-sectional study. Materials and methods Patients with thrombocytopenia (platelet count < 150,000/microL) admitted between January and December 2022 were included. Patients with pseudothrombocytopenia were excluded. Demographic, clinical, and laboratory data were collected through manual review of electronic medical records. Etiologies were recorded, and statistical analysis was performed using Stata software. Here and throughout, n denotes the number of patients contributing data to a given comparison, and N denotes the total cohort (N = 114). Where applicable, denominators were adjusted for missing data. Results Of 114 patients, 73 (64.04%) were male. The mean age was 40.80 ± 15.93 years, and the mean length of hospital stay was 11.83 ± 15.73 days. The mean platelet count was 51,480 ± 39,690/microL. Mild thrombocytopenia was observed in 19 (16.67%) patients, moderate in 31 (27.19%), and severe in 64 (54.14%). Infection was the most common etiology (n = 48, 42.11%), with Plasmodium species accounting for the largest number of cases (n = 25). Bleeding manifestations were observed in 72 (63.07%) patients, most commonly epistaxis (n = 16, 14.04%), ecchymosis (n = 13, 11.4%), and petechiae (n = 9, 7.89%). Patients with bleeding, particularly petechiae, ecchymosis, epistaxis, and gum bleeding, had significantly lower platelet counts than those without bleeding symptoms. Conclusion Infections were the predominant cause of thrombocytopenia in this cohort. Lower platelet counts were significantly associated with bleeding manifestations, particularly epistaxis, emphasizing the need for early recognition and appropriate clinical management.

Severe ADAMTS13 deficiency causes congenital thrombotic thrombocytopenic purpura (cTTP), a potentially life-threatening thrombotic microangiopathy. Considering ADAMTS13 regulates thrombosis, ADAMTS13 activity might correlate with clinical outcomes in cTTP; however, evidence evaluating this relationship remains limited.

Cytomegalovirus (CMV) establishes lifelong latency following primary infection and can reactivate to cause severe illness in immunocompromised hosts. CMV DNAemia in non-HIV-infected, non-solid organ/bone marrow transplant (NHNT) hosts is poorly characterized, with limited clinical insights. We aim to describe the clinical presentation, prognostic indicators, and outcomes of CMV DNAemia among NHNT patients. We used the TriNetX international patient database to identify adult patients diagnosed with CMV DNAemia from 2016 until March 2023. We evaluated hospitalization, intensive care unit (ICU) level care, and all-cause mortality at 30 days and 1 year. We also completed a post-propensity score analysis comparing clinical characteristics of survivors versus non-survivors at 90 days. We identified 1123 NHNT patients with CMV DNAemia, most of whom had neoplasms (63%). Venous thromboembolism occurred in 31% of the population. The 30-day hospitalization and all-cause mortality rates were 35% and 14%, respectively. After propensity score matching and Bonferroni correction, weakness, purpura, acute respiratory failure, malnutrition, encephalopathy, and hypotension were associated with increased 90-day all-cause mortality. NHNT patients with CMV DNAemia carry a substantial morbidity and all-cause mortality. Further studies are warranted to clarify whether CMV DNAemia is a causative factor or an incidental finding in this population.

Upshaw-Schulman syndrome (USS) is a rare inherited autosomal recessive thrombotic microangiopathy affecting less than 1/1,000,000 individuals. It is a congenital form of thrombotic thrombocytopenic purpura (TTP) caused by ADAMTS13 protease deficiency because of mutations in the ADAMTS13 gene. USS is characterized by the formation of platelet thrombi in the microcirculation, accompanied by hemolytic anemia, thrombocytopenia, and clinical and laboratory signs of renal and neurological failure. The aim of this study was to describe the ADAMTS13 gene mutation spectrum in the Russian population. We analyzed the ADAMTS13 gene in 45 unrelated patients with TTP of unknown origin. DNA was extracted from blood cells using the phenol-chlorophorm method, and all exons of the gene were investigated using Sanger sequencing. In 15 out of 45 patients, we identified 20 different variants associated with USS, including two frameshift, two variants affecting the splice site, one nonsense and fifteen missense mutations. Eight out of those mutations were previously undescribed. Tree variants were revealed more than once: p.Arg1060Trp (7 patients), p.Glu1326ArgfsTer6 (7 patients) and p.Cys1067SerfsTer30 (3 patients). Variants (p.Arg1060Trp) and p.Glu1326ArgfsTer6 prevailed in the global population; however, p.Cys1067SerfsTer30 was not previously described in the European population. Our results expand the existing knowledge of the molecular basis of USS and may contribute to improved genetic diagnostics in Russia.

IgA vasculitis (IgAV) primarily affects small vessels, but rare cases with necrotizing arteritis (NA) raise questions about overlap with polyarteritis nodosa (PAN). To characterize IgAV with necrotizing arteritis (IgAV-NA) and compare its phenotype with classical IgAV and PAN. We performed a multicenter retrospective study combined with a systematic literature review (1990-2025). Patients fulfilled EULAR/PRINTO/PRES IgAV criteria, had pathological or imaging evidence of NA in small or medium arteries, and were ANCA-negative. Thirty patients were included (7 from databases, 23 from the literature). NA was confirmed by biopsy (n = 16) or vascular imaging (n = 14). Clinical features, treatments, remission, and mortality were compared with 257 adult IgAV and 196 PAN patients. Median age was 54.5 years. IgAV-NA was characterized by severe manifestations, including gastrointestinal bleeding, perforation, surgical abdomen, neuropathy, pancreatitis, and livedo. Compared with classical IgAV, IgAV-NA showed significantly higher rates of multi-organ involvement and mortality. Compared with PAN, IgAV-NA shared vascular complications but had less fever and neuropathy. Despite arterial involvement, patients did not fulfil PAN criteria. IgAV-NA represents a rare, severe IgAV phenotype with life-threatening complications rather than an IgAV-PAN overlap. Severe or atypical IgAV presentations should prompt vascular imaging and intensified immunosuppression.

Legionnaires' disease is a severe form of pneumonia most commonly caused by Legionella pneumophila serogroup 1. While primarily affecting the lungs, extrapulmonary manifestations such as hyponatremia, renal dysfunction, and hepatic involvement are well described. In contrast, cutaneous manifestations are rare and remain poorly characterized. We report the case of a 62-year-old immunocompetent man with a history of chronic alcohol use and active smoking who presented with fever, dyspnea, and productive cough. On admission, he was febrile (38.5°C), tachycardic, and had crackles over the right lower lung field. Laboratory evaluation revealed hyponatremia (132 mmol/L) and markedly elevated inflammatory markers (CRP 480 mg/L, procalcitonin 41 ng/mL). Chest imaging demonstrated right lower lobe pneumonia. Initial empiric therapy with amoxicillin-clavulanate was started. Within 48 hours, the patient developed acute respiratory failure requiring intubation and ICU admission. Urinary antigen testing confirmed Legionella pneumophila infection, and antibiotic therapy was switched to levofloxacin and spiramycin. The course was complicated by severe ARDS (PaO2/FiO2 ratio 100) requiring prone positioning, and septic shock requiring vasopressors. On day 9 of hospitalization (seven days after targeted therapy initiation), the patient developed a diffuse, non-pruritic erythematous maculopapular rash with targetoid lesions, involving the trunk and limbs, with palmar involvement and petechiae at the ankles, without mucosal involvement. A drug eruption was initially suspected; however, skin biopsy showed mild interkeratinocytic edema with superficial lymphocytic infiltrate and rare keratinocyte necrosis, without eosinophilia or features of toxidermia. Direct immunofluorescence and PCR testing for herpes simplex virus and Mycoplasma pneumoniae were negative. These findings supported a diagnosis of erythema multiforme (EM) secondary to Legionella infection. The rash resolved spontaneously without specific treatment. The patient improved clinically, was extubated on day 12, weaned off vasopressors by day 10, and discharged on day 20 after completing antibiotic therapy. This case illustrates a rare presentation of Legionnaires' disease complicated by EM. Recognition of this association is important, as cutaneous findings may mimic drug reactions and lead to inappropriate modification of effective antimicrobial therapy. This report contributes to the limited literature describing dermatologic manifestations of Legionella infection and underscores the need for clinical awareness of this uncommon presentation.