Rare primary vasculitis: update on multiple complex diseases and the new kids on the block.

Systemic vasculitis is a group of rare diseases that share an essential characteristic: inflammation of blood vessel walls. This injury occurs during the disease course, but specific features vary for each entity. In this paper, we will address relevant aspects of the newest monogenic mutation vasculitis, such as deficiency of adenosine deaminase 2 (ADA2) and VEXAS syndrome (UBA1), and other relevant vasculitis, such as Cogan syndrome and Susac syndrome that may share some similarities with them.

Long-term cardiovascular inflammation and fibrosis in a murine model of vasculitis induced by Lactobacillus casei cell wall extract.

Background: Kawasaki disease (KD), an acute febrile illness and systemic vasculitis, is the leading cause of acquired heart disease in children in industrialized countries. KD leads to the development of coronary artery aneurysms (CAA) in affected children, which may persist for months and even years after the acute phase of the disease. There is an unmet need to characterize the immune and pathological mechanisms of the long-term complications of KD. Methods: We examined cardiovascular complications in the Lactobacillus casei cell wall extract (LCWE) mouse model of KD-like vasculitis over 4 months. The long-term immune, pathological, and functional changes occurring in cardiovascular lesions were characterized by histological examination, flow cytometric analysis, immunofluorescent staining of cardiovascular tissues, and transthoracic echocardiogram. Results: CAA and abdominal aorta dilations were detected up to 16 weeks following LCWE injection and initiation of acute vasculitis. We observed alterations in the composition of circulating immune cell profiles, such as increased monocyte frequencies in the acute phase of the disease and higher counts of neutrophils. We determined a positive correlation between circulating neutrophil and inflammatory monocyte counts and the severity of cardiovascular lesions early after LCWE injection. LCWE-induced KD-like vasculitis was associated with myocarditis and myocardial dysfunction, characterized by diminished ejection fraction and left ventricular remodeling, which worsened over time. We observed extensive fibrosis within the inflamed cardiac tissue early in the disease and myocardial fibrosis in later stages. Conclusion: Our findings indicate that increased circulating neutrophil counts in the acute phase are a reliable predictor of cardiovascular inflammation severity in LCWE-injected mice. Furthermore, long-term cardiac complications stemming from inflammatory cell infiltrations in the aortic root and coronary arteries, myocardial dysfunction, and myocardial fibrosis persist over long periods and are still detected up to 16 weeks after LCWE injection.

Navigating the diagnostic maze: A case presentation of C1q vasculitis mimicking hypocomplementemic urticarial vasculitis in a patient with systemic lupus erythematosus.

In rare instances, patients with SLE may exhibit atypical clinical manifestations, such as Hypocomplementemic Urticarial Vasculitis, which can pose diagnostic challenges. Here, we present a case report of a 28-year-old female with a history of SLE with lupus nephritis clase IV who developed HUV-like symptoms, ultimately leading to a diagnosis of C1q Vasculitis. This case underscores the importance of considering C1q Vasculitis in SLE patients presenting with HUV-like features and highlights Rituximab as a promising therapeutic option for managing this rare condition.

ANCA in patients with systemic lupus erythematosus. A cross sectional study in Brazilian patients and review of literature.

BACKGROUND: Antineutrophil cytoplasmatic antibodies (ANCA) have been detected in patients with systemic lupus erythematosus (SLE). In this study, we investigated the presence of ANCA in a sample of Brazilian SLE patients and its possible associations with clinical and serological outcomes. Additionally, we reviewed the literature of on ANCA in SLE. RESULTS: The presence of ANCA was detected in 130 patients using indirect immunofluorescence (IIF). The test was positive in 29.9% of the cases (17.6% pANCA and 11.5% cANCA). Male sex and peripheral vasculitis were more prevalent in the ANCA-positive sample. cANCA was associated with lupus anticoagulant and pANCA had a positive association with peripheral vasculitis and a negative association with anti- SSB/La antibodies. In the 22 studies included in the literature review, a wide range of ANCA positivity was found (13% to 81.1% by IIF and 0 to 22.2% by ELISA). ANCA was associated with renal damage in the Asian population. Although other associations have been found in isolated studies, they were not consistently reported. CONCLUSIONS: The ANCA prevalence found in this Brazilian sample was within the range reported in the literature and these autoantibodies were more frequent in males and in patients with vasculitis. The literature showed controversial results on the association between ANCA and SLE disease activity or clinical characteristics.

Síndrome de Ramsay-Hunt associada à meningite e vasculite em indivíduo imunocompetente / Ramsay-Hunt syndrome associated with meningitis and vasculitis in an immunocompetent individual

O vírus varicela zoster (VVZ) causa a varicela como infecção primária e sua reativação leva à herpes zóster, que é uma erupção cutânea vesicular dolorosa na distribuição de um dermátomo associado à neuralgia. A sua reativação no sistema nervoso central também é possível e acontece sob a forma de meningite, meningoradiculite, mielopatia, vasculite e síndrome de Ramsay-Hunt. Neste relato, descrevemos o caso de um paciente de 22 anos do sexo masculino e previamente hígido, que apresentou hemiplegia à direita e paralisia facial periférica associada a vesículas dolorosas em pavilhão auditivo ipsilateral, febre e cefaleia. A ressonância magnética de encéfalo com estudo dos vasos arteriais evidenciou achados compatíveis com vasculite em segmento longo da artéria carótida interna à esquerda. Apesar das pesquisas dos vírus da família herpes por biologia molecular terem sido negativas no líquor, pudemos documentar altos títulos de anticorpos IgG para varicela zoster em duas amostras diferentes de sangue periférico. Decorridas duas semanas do início do tratamento com aciclovir parenteral, o paciente já se encontrava assintomático e com melhora expressiva dos déficits neurológicos. O presente relato ressalta a importância de incluir a reativação do VVZ como causa de meningite e vasculite em indivíduos jovens, sem comorbidades e aparentemente imunocompetentes.

Síndrome mielodisplásica e sua associação com doença autoimune / Myelodysplastic syndrome associated with autoimmune disease

Síndromes mielodisplásicas associadas a doenças autoimunes sistêmicas são descritas por muitos autores. Doenças da tireoide, vasculites, doenças do tecido conjuntivo, artrites e alterações cutâneas são as mais relatadas. Nos últimos anos tivemos avanços e o que foi descoberto recentemente é que mutações genéticas específicas envolvidas na fisiopatologia da SMD têm como consequência a ativação exacerbada da resposta imune inata, sendo o inflamassoma protagonista. Eles consistem em complexos multiproteicos intracelulares que quando ativados, liberam interleucinas inflamatórias e direcionam a célula para a morte celular dependente de caspase-1, chamada piroptose. Essa ativação exacerbada da resposta imune inata, foi relacionada por alguns autores com o aparecimento da SMD e da doença autoimune. Outra célula com importante papel nesta fisiopatologia são as células supressoras derivadas de mieloides (MDSCs), seu surgimento aparece no câncer e em condições patológicas associadas a inflamação ou estresse. Ela é responsável pela supressão de diferentes células do sistema imunológico, em especial os linfócitos T, facilitando a progressão do tumor. Em relação ao prognóstico, observamos resultados controversos, porém os maiores estudos demonstram um aumento de sobrevida, isso é correlacionado por alguns autores pela redução de linfócitos T reguladores. Esse trabalho tem como objetivo fazer uma revisão na literatura sobre a fisiopatologia dessa associação, doenças mais comuns e prognóstico

Myelodysplastic syndromes associated with systemic autoimmune diseases are described by many authors. Thyroid diseases, vasculitis, connective tissue diseases, arthritis and skin changes are the most reported. In recent years we have made advances and what has recently been discovered is that specific genetic mutations involved in the pathophysiology of MDS result in exacerbated activation of the innate immune response, with the inflammasome being the protagonist. They consist of intracellular multiprotein complexes that, when activated, release inflammatory interleukins and direct the cell toward caspase-1-dependent cell death, called pyroptosis. This exacerbated activation of the innate immune response has been related by some authors to the appearance of MDS and autoimmune disease. Another cell with an important role in this pathophysiology are myeloid-derived suppressor cells (MDSCs), their appearance appears in cancer and in pathological conditions associated with inflammation or stress. It is responsible for suppressing different cells of the immune system, especially T lymphocytes, facilitating tumor progression. Regarding the prognosis, we observed controversial results, however the largest studies demonstrate an increase in survival, which is correlated by some authors with the reduction of regulatory T lymphocytes. This work aims to review the literature on the pathophysiology of this association, most common diseases and prognosis

A Rare Skin Rash: Linezolid-Induced Purpuric Drug Eruption without Vasculitis in a Puerto Rican Man.

BACKGROUND Cutaneous adverse drug reactions are the skin's response to a systemic exposure to drugs. Linezolid is an oral oxazolidine used to treat methicillin-resistant Staphylococcus aureus infections. Even though it has well-known adverse effects, purpuric cutaneous adverse drug reactions to linezolid have been scarcely described. This report is of a Puerto Rican man in his 80s who developed an extensive purpuric drug eruption secondary to linezolid use. Clinicians should be aware of this phenomenon, since prompt identification and discontinuation of the agent are essential for recovery. CASE REPORT An 89-year-old Puerto Rican man was given oral linezolid therapy for healthcare-associated pneumonia and developed a widespread, purpuric cutaneous eruption 5 days into therapy. His condition prompted immediate discontinuation of the drug. Forty-eight hours after stopping the medication, he visited the Emergency Department. Abdominal punch biopsy revealed a superficial and perivascular lymphocytic infiltrate with dermal eosinophils, a pathologic finding consistent with a purpuric drug eruption. This allowed for a timely diagnosis, exclusion of other mimickers, such as cutaneous vasculitis, and effective management. CONCLUSIONS Cutaneous adverse drug reactions to linezolid have been scarcely reported in the literature. Due to the low incidence of this manifestation, the identification of the causative agent and accompanying treatment may be delayed. Mainstays in therapy are avoidance of the offending agent and treatment with corticosteroids, antihistamines, barrier ointments, and oral analgesics. Primary healthcare providers should be aware of linezolid-induced cutaneous manifestations, diagnostic clues, and treatment options so they can rapidly identify and effectively treat such complications.

Reporte de pacientes con espondiloartritis y arteritis de Takayasu en Argentina: ¿asociación causal o casual? / Report of patients with spondyloarthritis and Takayasu's arteritis in Argentina: is it a causal or casual association?

Introducción: tanto las espondiloartritis (EspA) como la arteritis de Takayasu (TAK) son enfermedades infrecuentes y su asociación es aún más rara. Objetivos: presentar una serie de pacientes con diagnóstico concomitante de EspA o con rasgos de EspA y TAK en Argentina, y realizar una revisión de la literatura respecto de esta asociación. Materiales y métodos: se recopilaron las características demográficas, clínicas y terapéuticas de pacientes con diagnóstico concomitante de EspA o con algunos rasgos de EspA y TAK, de distintos centros de salud de la República Argentina. Resultados: se describen 7 pacientes, de los cuales 4 presentaban EspA, uno con compromiso axial (EspAax) juvenil, otro con artritis psoriásica (APs), otro con espondilitis anquilosante (EA) y el último con EspAax pura, y 3 de ellos tuvieron rasgos de EspA (enfermedad Crohn, psoriasis y oligoartritis asimétrica de grandes articulaciones). En la mayoría de los casos, los rasgos de EspA se presentaron con una mediana de 4 años antes de la TAK. Conclusiones: varios reportes y series de casos relatan la superposición entre estas dos enfermedades. Si bien las mismas podrían compartir cierta base genética común, todavía no contamos con evidencia sólida que permita estimar que esta asociación no es casual.

Introduction: both spondyloarthritis (SpA) and Takayasu arteritis (TAK) are rare diseases, and their association is even rarer. Objectives: to present a series of patients with a concomitant diagnosis of SpA or with features of SpA and TAK in Argentina and review the literature regarding this association. Materials and methods: the demographic, clinical and therapeutic characteristics of patients with a concomitant diagnosis of SpA or with some features of SpA and TAK were collected from different health centers in Argentina. Results: 7 patients are described, of which 4 had SpA, one with juvenile axial involvement (axSpA), another with psoriatic arthritis (PsA), another with ankylosing spondylitis (AS) and the last patient with pure axSpA and 3 of them had features of SpA (Crohn's disease, psoriasis and asymmetric oligoarthritis of large joints). In most cases, SpA features presented a median of 4 years before TAK. Conclusions: several case reports and case series reported overlap between these two diseases. Although they could share a certain common genetic basis, we still do not have solid evidence that allows us to estimate that this association is not coincidental.

The role of TNF receptors as mediators of chronic vasculitis in possible milder forms of the CNS tuberculosis.

INTRODUCTION: Central nervous system (CNS) tuberculosis (TB) is the most severe form of TB due to its high mortality and functional sequelae. There are several differential diagnoses for TB; and, it can also cause secondary conditions, such as vasculitis. METHODOLOGY: 155 biopsies, corresponding to 155 different patients out of 5,386 registered biopsies from 2008-2013, met the criteria of unknown etiology vasculitis and evidence of cerebral vascular disease. These were analyzed to assess the presence of central nervous system TB. The selected cases were assessed with Suzaan Marais (SM) criteria for clinical tuberculosis. After that, Ziehl-Neelsen (ZN) staining and polymerase chain reaction (PCR) were performed to amplify a fragment of the insertion sequence IS6110 of M. tuberculosis. 21 patients met the criteria for definitive tuberculosis by ZN staining and PCR, and 2 met the criteria for possible tuberculosis. Tumor necrosis factor (TNF)-α, TNF-R1, and TNF-R2 were determined by immunohistochemistry in histological sections from formalin-fixed paraffin-embedded (FF-PE) tissues in the 23 selected patients. RESULTS: Granulomatous TB was present in almost half of the cases. TNF-R1 and TNF-R2 were expressed mainly in blood vessels, histiocytes, and macrophages. TNF-R2 expression was higher than the other markers, which suggests an anti-inflammatory response against M. tuberculosis. CONCLUSIONS: The histopathological presentation of TB is not always limited to granulomas, abscesses, or meningitis; there are also clinical presentations characterized only with chronic inflammation of nervous and vascular tissue.

Reporte de caso: vasculitis leucocitoclastica como forma de presentación de hepatitis b crónica / Case report: leukocytoclastic vasculitis as presenting manifestation of chronic hepatitis b virus infection

La vasculitis leucocitoclástica, también denominada angeitis cutánea leucocitoclástica, es la forma más común de vasculitis. Si bien la mayoría de los casos son idiopáticos, entre los agentes etiológicos que podemos nombrar se encuentran los agentes infecciosos, las enfermedades del tejido conectivos, las reacciones de hipersensibilidad a medicamentos y las neoplasias solidas o hematológicas. Si bien los procesos infecciosos son una causa conocida de vasculitis leucocitoclástica, la infección por virus de Virus de hepatitis B (VHB) es muy infrecuente. Presentamos una mujer de 47 años, sin antecedentes patológicos previos, que consultó por artralgias en rodillas y tobillos, mialgias en gemelos y rash purpúrico con leve prurito en ambos miembros inferiores, de un mes de evolución. La biopsia cutánea de las lesiones de miembros inferiores fue compatible con vasculitis leucocitoclástica. La serología de hepatitis B fue positiva por lo que inició tratamiento antiviral con Tenofovir y Prednisona con buena evolución de sus lesiones cutáneas

Leukocytoclastic vasculitis, also called leukocytoclastic cutaneous angiitis, is the most common form of vasculitis. Although most cases are idiopathic, etiologic agents include infectious agents, connective tissue diseases, drug hypersensitivity reactions, and solid or hematologic malignancies. Although infectious processes are a known cause of leukocytoclastic vasculitis, hepatitis B virus (HBV) infection is very rare. We present a 47-year-old woman, with no previous pathologic history, who consulted for arthralgias in the knees and ankles, myalgia's and purpuric rash with mild pruritus in both lower limbs, of one month evolution. Skin biopsy of lower extremity lesions was compatible with leukocytoclastic vasculitis. Hepatitis B serology was positive, so she started antiviral treatment with tenofovir and prednisone with good evolution of her skin lesions

Clinical, radiological and laboratory characteristics of central nervous system histoplasmosis: A systematic review of a severe disease.

BACKGROUND: The knowledge of central nervous system (CNS) histoplasmosis is limited to case reports and series. OBJECTIVES: Our objective was to synthesise clinical, radiological and laboratory characteristics of CNS histoplasmosis to improve our understanding of this rare disease. METHODS: We performed a systematic review using Pubmed/MEDLINE, Embase and LILACS databases accessed on March 2023 without publication date restrictions. Inclusion criteria comprised: (1) histopathological, microbiological, antigen or serological evidence of histoplasmosis; (2) CNS involvement based on cerebrospinal fluid pleocytosis or neuroimaging abnormalities. We classified the certainty of the diagnosis in proven (CNS microbiological and histopathological confirmation), probable (CNS serological and antigen confirmation) or possible (non-CNS evidence of histoplasmosis). Metaproportion was used to provide a summary measure with 95% confidence intervals for the clinical, radiological and laboratory characteristics. Chi-squared test was used to compare mortality between pairs of antifungal drugs. RESULTS: We included 108 studies with 298 patients. The median age was 31 years, predominantly male, and only 23% were immunocompromised (134/276, 95%CI: 3-71), mainly due to HIV infection. The most common CNS symptom was headache (130/236, 55%, 95%CI: 49-61), with a duration predominantly of weeks or months. Radiological presentation included histoplasmoma (79/185, 34%, 95%CI: 14-61), meningitis (29/185, 14%, 95%CI: 7-25), hydrocephalus (41/185, 37%, 95%CI: 7-83) and vasculitis (18/185, 6%, 95%CI: 1-22). There were 124 proven cases, 112 probable cases and 40 possible cases. The majority of patients presented positive results in CNS pathology (90%), serology (CSF: 72%; serum: 70%) or CSF antigen (74%). Mortality was high (28%, 56/198), but lower in patients who used liposomal amphotericin B and itraconazole. Relapse occurred in 13% (23/179), particularly in HIV patients, but less frequently in patients who used itraconazole. CONCLUSION: Central nervous system histoplasmosis usually presents subacute-to-chronic symptoms in young adults. Neuroimaging patterns included not only focal lesions but also hydrocephalus, meningitis and vasculitis. Positive results were commonly found in CSF antigen and serology. Mortality was high, and treatment with liposomal amphotericin B followed by itraconazole may decrease mortality.

A brazilian nationwide multicenter study on deficiency of deaminase-2 (DADA2).

INTRODUCTION: The deficiency of ADA2 (DADA2) is a rare autoinflammatory disease provoked by mutations in the ADA2 gene inherited in a recessive fashion. Up to this moment there is no consensus for the treatment of DADA2 and anti-TNF is the therapy of choice for chronic management whereas bone marrow transplantation is considered for refractory or severe phenotypes. Data from Brazil is scarce and this multicentric study reports 18 patients with DADA2 from Brazil. PATIENTS AND METHODS: This is a multicentric study proposed by the Center for Rare and Immunological Disorders of the Hospital 9 de Julho - DASA, São Paulo - Brazil. Patients of any age with a confirmed diagnosis of DADA2 were eligible for this project and data on clinical, laboratory, genetics and treatment were collected. RESULTS: Eighteen patients from 10 different centers are reported here. All patients had disease onset at the pediatric age (median of 5 years) and most of them from the state of São Paulo. Vasculopathy with recurrent stroke was the most common phenotype but atypical phenotypes compatible with ALPS-like and Common Variable Immunodeficiency (CVID) was also found. All patients carried pathogenic mutations in the ADA2 gene. Acute management of vasculitis was not satisfactory with steroids in many patients and all those who used anti-TNF had favorable responses. CONCLUSION: The low number of patients diagnosed with DADA2 in Brazil reinforces the need for disease awareness for this condition. Moreover, the absence of guidelines for diagnosis and management is also necessary (t).

[Kawasaki disease cytokine release syndrome and Kawasaki disease shock syndrome: A case report]. / Síndrome de tormenta de citocinas y síndrome de choque por enfermedad de Kawasaki: reporte de un caso.

BACKGROUND: Kawasaki disease is a vasculitis of small and medium vessels, with a high prevalence throughout the world. In addition to coronary aneurysms, this vasculitis can lead to a number of systemic complications, including Kawasaki disease shock syndrome and Kawasaki disease cytokine storm syndrome. CASE REPORT: : Case report: A 12-year-old male patient, who began his condition with heartburn, sudden fever of 40 ºC and jaundice, for which he was prescribed treatment with antipyretics and bismuth subsalicylate, without satisfactory reaction. Gastroalimentary content was added three times, and centripetal maculopapular dermatosis. After 12 hospital stays, he was evaluated by personnel from the Pediatric Immunology service, who reported data on hemodynamic instability due to persistent tachycardia for hours, immediate capillary refill, intense pulse, oliguria of 0.3 mL/kg/h of partial urinary output with condensed urine; the systolic blood pressure figures were below the 50% percentile, and there was polypnea and limit saturation in 93%. In the paraclinical studies, the rapid decrease in platelet count (from 297,000 to 59,000 in 24 hours), as well as a neutrophil-lymphocyte index of 12, drew attention. The concentrations of NS1 size, IgM and IgG for dengue and PCR for SARS virus were determined. -CoV-2, which were negative. The definitive diagnosis of Kawasaki disease was established with Kawasaki disease shock syndrome. The evolution of the patient was satisfactory, with a decrease in fever after the administration of gamma globulin on the tenth day of hospitalization, and a new protocol with prednisone (50 mg/day) was started, when the cytokine storm syndrome due to illness was integrated. Kawasaki syndrome simultaneous with pre-existing disorders, that is, Kawasaki disease and Kawasaki disease shock syndrome due to thrombocytopenia, hepatosplenomegaly, fever, lymphadenopathy; in addition, ferritin of 605 mg/dL and transaminasemia. The control echocardiogram did not show coronary abnormalities and hospital discharge was granted 48 hours after starting treatment with the corticosteroid, with a 14-day follow-up plan. CONCLUSIONS: Kawasaki disease is an autoimmune vasculitis that can worsen with simultaneous syndromes associated with high mortality. It is important to know this type of alterations and their differences to properly discern and implement effective and timely treatment.

INTRODUCCIÓN: La enfermedad de Kawasaki es una vasculitis de pequeños y medianos vasos, con elevada prevalencia en todo el mundo. Además de los aneurismas coronarios, esta vasculitis puede generar diversas complicaciones sistémicas, como el síndrome de choque por enfermedad de Kawasaki y el síndrome de tormenta de citocinas por enfermedad de Kawasaki. REPORTE DE CASO: Paciente masculino de 12 años de edad, que inició su padecimiento con pirosis, fiebre súbita de 40 ºC e ictericia, por lo que se le prescribió tratamiento con antipiréticos y subsalicilato de bismuto, sin reacción satisfactoria. Se agregó vómito de contenido gastroalimentario en tres ocasiones y dermatosis maculopapular centrípeta. Después de 12 horas de estancia intrahospitalaria fue valorado por personal del servicio de Inmunología Pediátrica, quienes informaron datos de inestabilidad hemodinámica por taquicardia persistente, llenado capilar inmediato, pulso intenso, oliguria de 0.3 mL/kg/h de gasto urinario parcial con orina condensada; las cifras de tensión arterial sistólica se encontraban debajo del percentil 50%, y había polipnea y saturación limítrofe en 93%. En los estudios paraclínicos llamó la atención el rápido descenso del conteo plaquetario (de 297,000 a 59,000 en 24 horas), así como el índice neutrófilo-linfocito de 12. Se determinaron las concentraciones de antígeno NS1, IgM e IgG para dengue y PCR para virus SARS-CoV-2, que resultaron negativas. Se estableció el diagnóstico definitivo de enfermedad de Kawasaki con síndrome de choque por enfermedad de Kawasaki. La evolución del paciente fue satisfactoria, con disminución de la fiebre luego de la administración de gammaglobulina en el décimo día de hospitalización, y se inició un nuevo protocolo con prednisona (50 mg/día), al integrarse el síndrome de tormenta de citocinas por enfermedad de Kawasaki simultáneo con las alteraciones preexistentes, es decir: enfermedad de Kawasaki y síndrome de choque por enfermedad de Kawasaki por trombocitopenia, hepatoesplenomegalia, fiebre, adenopatías; además, ferritina de 605 mg/dL y transaminasemia. El ecocardiograma de control no mostró modificaciones coronarias y se otorgó el alta hospitalaria después de 48 horas de iniciar el tratamiento con el corticosteroide, con plan de seguimiento en 14 días. CONCLUSIONES: La enfermedad de Kawasaki es una vasculitis autoinmunitaria que puede agravarse con síndromes simultáneos asociados y generar elevada mortalidad. Es importante conocer este tipo de alteraciones y sus diferencias para discernir de forma adecuada e implementar el tratamiento eficaz y oportuno.

Schõnlein-Henoch purpura in adults: Report of four cases

Schoenlein-Henoch purpura is a systemic small vessel vasculitis mediated by IgA-1 deposition in organs such as the skin, kidney, and gastrointestinal tract; it has been mainly described in children where it has a favourable prognosis. Although much rarer in adulthood it is associated with an increased risk of severe kidney involvement, gastrointestinal com-plications, and prolonged hospital stay. The therapeutic options are wide and vary according to the degree of involvement of the patient and the organ mainly affected.

La púrpura de Schönlein-Henoch es una vasculitis sistêmica de pequeno vaso mediada por depósito de IgA en órganos como la piel, el riñón y el tracto gastrointestinal. Se ha descrito principalmente en niños, grupo de población en el que tiene un pronóstico favorable. Si bien en la edad adulta es mucho menos frecuente, se asocia con un mayor riesgo de compromiso renal severo, complicaciones gastrointestinales y estancia hospitalaria prolongada. Las opciones terapêuticas son amplias y varían según el grado de compromiso del paciente y el órgano más afectado.

Mycobacterium tuberculosis Cell Wall Antigens Induce the Formation of Immune Complexes and the Development of Vasculitis in an Experimental Murine Model.

Tuberculosis (TB) of the central nervous system (CNS) presents high mortality due to brain damage and inflammation events. The formation and deposition of immune complexes (ICs) in the brain microvasculature during Mycobacterium tuberculosis (Mtb) infection are crucial for its pathobiology. The relevance of ICs to Mtb antigens in the pathogenesis of CNS-TB has been poorly explored. Here, we aimed to establish a murine experimental model of ICs-mediated brain vasculitis induced by cell wall antigens of Mtb. We administered a cell wall extract of the prototype pathogenic Mtb strain H37Rv to male BALB/c mice by subcutaneous and intravenous routes. Serum concentration and deposition of ICs onto blood vessels were determined by polyethylene glycol precipitation, ELISA, and immunofluorescence. Histopathological changes in the brain, lung, spleen, liver, and kidney were evaluated by hematoxylin and eosin staining. Our results evidenced that vasculitis developed in the studied tissues. High serum levels of ICs and vascular deposition were evident in the brain, lung, and kidneys early after the last cell wall antigen administration. Cell wall Mtb antigens induce strong type III hypersensitivity reactions and the development of systemic vasculitis with brain vascular changes and meningitis, supporting a role for ICs in the pathogenesis of TB.

Is Your Kid Actin Out? A Series of Six Patients With Inherited Actin-Related Protein 2/3 Complex Subunit 1B Deficiency and Review of the Literature.

BACKGROUND: Hereditary actin-related protein 2/3 complex subunit 1B deficiency is characterized clinically by ear, skin, and lung infections, bleeding, eczema, food allergy, asthma, skin vasculitis, colitis, arthritis, short stature, and lymphadenopathy. OBJECTIVE: We aimed to describe the clinical, laboratory, and genetic features of six patients from four Mexican families. METHODS: We performed exome sequencing in patients of four families with suspected actinopathy, collected their data from medical records, and reviewed the literature for reports of other patients with actin-related protein 2/3 complex subunit 1B deficiency. RESULTS: Six patients from four families were included. All had recurrent infections, mainly bacterial pneumonia, and cellulitis. A total of 67% had eczema whereas 50% had food allergies, failure to thrive, hepatomegaly, and bleeding. Eosinophilia was found in all; 84% had thrombocytopenia, 67% had abnormal-size platelets and anemia. Serum levels of IgG, IgA, and IgE were highly increased in most; IgM was normal or low. T cells were decreased in 67% of patients, whereas B and NK cells were increased in half of patients. Two of the four probands had compound heterozygous variants. One patient was successfully transplanted. We identified 28 other patients whose most prevalent features were eczema, recurrent infections, failure to thrive, bleeding, diarrhea, allergies, vasculitis, eosinophilia, platelet abnormalities, high IgE/IgA, low T cells, and high B cells. CONCLUSION: Actin-related protein 2/3 complex subunit 1B deficiency has a variable and heterogeneous clinical spectrum, expanded by these cases to include keloid scars and Epstein-Barr virus chronic hepatitis. A novel deletion in exon 8 was shared by three unrelated families and might be the result of a founder effect.