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Biomedical subjects

Nima Parvaneh

Publications and source records attributed to Nima Parvaneh.

7 recordsLinked to original sources

ER proteostasis failure in HYOU1 deficiency alters B cells, neutrophils, and interferon signalling.

Hypoxia upregulated 1 (HYOU1) is a stress-inducible ER chaperone. We investigated 2 unrelated patients carrying biallelic HYOU1 variants and presenting with primary immunodeficiency. Patient 1, homozygous for p.Pro444His, displayed failure to thrive, hypoglycemia, B cell lymphopenia, and neutropenia. Patient 2, compound heterozygous for p.Arg262Gln and p.Pro757_Glu758insAla, exhibited recurrent infections, enteropathy, and hypogammaglobulinemia. In Patient 1, while HYOU1 transcription was preserved, the protein was severely reduced. Tunicamycin treatment of dermal fibroblasts showed a blunted unfolded protein response and defective induction of ER stress-responsive genes. Immunophenotyping showed near-absence of circulating B cells, and single-cell RNA sequencing of bone marrow identified an arrest at the pro-B cell stage. Neutrophils displayed hypogranulation and dysregulated IFN- and apoptosis-associated transcriptional signatures, unresponsive to G-CSF. HYOU1 deficiency hence results in ER stress-induced proteostasis failure that simultaneously impairs adaptive immunity through B cell developmental arrest and innate immunity through neutrophil dysfunction and IFN pathway imbalance. This work expands the spectrum of HYOU1 deficiency and further identifies ER proteostasis as a central determinant of immune homeostasis.

Journal Article↗

Human LFA-1 governs T cell immune surveillance of the skin.

The human integrin lymphocyte function-associated antigen 1 (LFA-1; αLβ2) is broadly expressed on leukocytes and involved in various intercellular adhesions. We report complete LFA-1 deficiency because of inherited αL (CD11a) deficiency in otherwise healthy adults of various ancestries with skin lesions due to commensal papillomaviruses. The patients had no history of invasive infections characteristic of children with inherited deficiency of β2 (CD18), which forms heterodimers with αL, αM (CD11b), αX (CD11c), or αD (CD11d). The development and function of leukocyte subsets are largely preserved in the absence of LFA-1. However, the transendothelial migration of skin-tropic cutaneous lymphocyte antigen (CLA)+ memory T cells is severely impaired, resulting in their selective sequestration in the blood. Conversely, alternative integrins mediate the extravasation of other leukocytes, including other T cell subsets, to other tissues. Human LFA-1 is required for steady-state T cell homing to the skin and control of papillomaviruses but is otherwise largely redundant. Integrin-mediated T cell compartmentalization is thus essential for organ-selective immune surveillance.

Humans↗

Mortality and morbidity in common variable immunodeficiency.

Common variable immunodeficiency (CVID) is a heterogeneous group of disorders, characterized by hypogammaglobulinemia, defective specific-antibody production resulting in recurrent bacterial infections. Delay in diagnosis and inadequate treatment result in increased irreversible complications and mortality. To determine persistent morbidities, mortality rate and survival in Iranian patients with CVID, hospital records of 72 (39 males and 33 females) diagnosed CVID patients were reviewed. Probabilities of survival after diagnosis of CVID were estimated from Kaplan-Meier life tables. Studied patients were enrolled over a 20-year period (1984-2005). The most commonly observed complication was bronchiectasis (24 cases), followed by splenomegaly, intestinal villous atrophy (11 cases), and failure to thrive (10 cases). Post-diagnosis survival was estimated as 65% for the first 6.5 years, which remains the same until 14 years after diagnosis when the survival curve drops to nearly 45%. The mortality rate among patients who had no regular visits and did not receive periodical IVIG was more remarkable when compared with those who had been followed up timely (p-value = 0.001). The most common cause of death was respiratory failure. Based on our observation, it can be highlighted that all patients with CVID, even under regular immunoglobulin replacement, need close monitoring for early detection of complications and introduction of appropriate management.

Adolescent↗

Progressive multifocal leukoencephalopathy in purine nucleoside phosphorylase deficiency.

Progressive multifocal leukoencephalopathy is a demyelinating disease caused by JC virus, an opportunistic infection of the central nervous system. Although the majority of cases are infected with the human immunodeficiency virus (HIV), other immunocompromised patients are also at risk. Purine nucleoside phosphorylase is an enzyme in the purine salvage pathway that reversibly converts inosine to hypoxanthine and guanosine to guanine. Purine nucleoside phosphorylase deficiency is a combined immunodeficiency with a profound cellular defect. Neurologic abnormalities are salient features of this syndrome. We describe for the first time a patient with this rare disorder presented with progressive multifocal leukoencephalopathy.

Child↗

Clinical, immunological and molecular characteristics of 37 Iranian patients with X-linked agammaglobulinemia.

BACKGROUND: X-linked agammaglobulinemia (XLA) is a hereditary immunodeficiency characterized by an early onset of recurrent bacterial infections, a profound deficiency of all immunoglobulin isotypes and a markedly reduced number of peripheral B lymphocytes. Eighty-five percent of the patients with this phenotype have mutations in Bruton's tyrosine kinase (BTK) gene. METHODS: To provide an informative outlook of clinical and immunological manifestations of XLA in Iran, 37 Iranian male patients with an age range of 1-34 years, followed over a period of 25 years, were studied. Twenty-four of the 37 patients were screened for BTK gene mutation using PCR-SSCP followed by direct sequencing. BTK protein expression assay was done by flow cytometry in 9 families. RESULTS: All patients first presented with infectious diseases, the most common of which were respiratory tract infections. Eighteen different mutations were identified, 13 of which were novel: IVS1+5G>C, 1896G>A, 349delA, 1618C>T, 1783T>C, 2084A>G, 1346delT, 1351delGAG, 587A>G, IVS14-1G>A, IVS3+2T>C, 1482G>A, 1975C>A. CONCLUSION: The fact that we found a great number of novel mutations in a relatively limited number of patients underlines the heterogeneity of BTK mutations in the Iranian population. The large number of new mutations indicates that extended studies in this region would be rewarding.

Adolescent↗

Lymphoma of mucosa-associated lymphoid tissue in common variable immunodeficiency.

Common variable immunodeficiency (CVID) is the most common symptomatic primary immunodeficiency characterized by reduced levels of all major immunoglobuline classes and recurrent c infections. The risk of non-Hodgkin's lymphoma (NHL) among patients with CVID was found to be increased in different studies. Mucosa-associated lymphoid tissue (MALT) lymphomas are a recently recognized sub-set of low-grade B-cell NHL composed of marginal zone-related cells. MALT lymphomas appear in the lymphoid tissues as a result of chronic inflammatory or autoimmune stimulation. This study briefly reviews previously published cases and reports a patient suffering from CVID with a history of chronic diarrhea and recurrent sinopulmonary infections. Despite treatment with intravenous immunoglobulin, chronic cough and wheezing progressed. Open lung biopsy showed a MALT lymphoma. Although a rare complication, pulmonary low grade B-cell lymphoma is a diagnosis that must be kept in mind in CVID patients with chronic pulmonary symptoms unresponsive to conventional therapies.

Adolescent↗