Case Reports in Immunology最新文献

Background: Immunoassays are commonly used in clinical laboratories to measure a variety of analytes, including hormones and tumor markers. Interference caused by rheumatoid factor (RF), heterophile antibodies, and human anti-animal antibodies (HAAA) has been reported but is rarely identified in daily practice. Here, we report a case of falsely elevated parathyroid hormone (PTH) due to immunoassay interference and review the literature.

Case presentation: A 57-year-old man who recovered well from lung metastasis of rectal cancer treated with bevacizumab and sintilimab for 1 year, presented to Peking University People's Hospital with persistently high PTH levels (>1200 ng/L) measured by a Roche Elecsys assay. He had hypoadrenocorticism induced by anti-programmed cell death 1 (PD-1), normal renal function, normal total calcium level, and normal 25-OH vitamin D concentration. The Beckman Coulter UniCel DxI 800 and Siemens Immulite 2000 platforms measured PTH levels of 18.3 ng/L and 8.7 ng/L, respectively. After the patient's serum was treated with polyethylene glycol (PEG) precipitation or mouse serum, the PTH levels determined by the Roche immunoassay decreased to 56.5 ng/L and 265.3 ng/L, respectively.

Conclusion: Interference due to human anti-mouse antibodies (HAMA) could be the cause of falsely elevated PTH in the patient. Physicians should realize that immunoassay interference can lead to false results and closely communicate with the laboratory to avoid misdiagnosis and inappropriate therapies.

We report a novel homozygous PRF1 variant, PRF1 (NM_001083116.3):c.343G > A (p.Glu115Lys), identified by whole-exome sequencing (WES) in an 11-year-old girl with atypical familial hemophagocytic lymphohistiocytosis (FHL). The variant, inherited from asymptomatic heterozygous parents, was absent or extremely rare in population databases and was predicted to be deleterious by multiple in silico tools. Born to consanguineous parents, the patient presented with recurrent fever, pancytopenia, and multiorgan failure following SARS-CoV-2 infection, further complicated by Epstein-Barr virus (EBV) and cytomegalovirus (CMV) coinfections. Despite intensive immunosuppressive therapy, she developed seizures, an intracranial hemorrhage, and died at age 11. A striking family history of unexplained febrile deaths in infancy and childhood strongly supported autosomal recessive inheritance. It emphasizes the role of viral triggers, especially COVID-19, in revealing genetic predispositions and underscores the importance of genetic screening in atypical cases.

Chronic granulomatous disease (CGD) is a primary immunodeficiency caused by defective phagocyte oxidative burst and may present in early life with severe or recurrent infections. We report a female infant born at 38 weeks' gestation (birth weight 2700 g) who developed fever and presumed sepsis at 5 days of life, followed by multiple recurrent hospitalizations for febrile illness with suspected meningitis, diarrhea, dehydration, and failure to thrive. Cerebrospinal fluid (CSF) evaluations across episodes demonstrated pleocytosis with elevated protein and normal-to-low glucose, while Gram stain and CSF cultures were repeatedly negative, consistent with recurrent culture-negative meningitis. Laboratory assessment showed intermittent anemia, thrombocytosis, and episodes of significant neutropenia. Complement and immunoglobulin levels were within reference ranges, and flow cytometry demonstrated preserved T- and B-lymphocyte compartments. A flow cytometric dihydrorhodamine (DHR) oxidative burst assay was markedly abnormal (phorbol 12-myristate 13-acetate stimulation index 13%; Escherichia coli stimulation index 22.3%), supporting the diagnosis of CGD. At ~4.5 months of age, a sterile catheter urine culture grew multidrug-resistant Klebsiella pneumoniae at ≥100,000 CFU/mL with susceptibility limited to aminoglycosides; the patient was treated with amikacin 15 mg/kg/dose intravenously once daily for 10 days, with defervescence within 48 h, clinical recovery, and a repeat urine culture showing no growth. Genetic testing was not performed due to financial and social constraints, and longer-term outcomes beyond early infancy were unavailable in the record extract. This case underscores that recurrent culture-negative meningitis in early infancy should prompt evaluation for primary immunodeficiency and that early DHR testing can expedite CGD diagnosis and guide timely preventive management and specialist referral.

Purpose: This study aims to present the diagnostic and therapeutic challenges of Cogan's syndrome (CS) and the outcomes of hearing rehabilitation in long-term follow-up.

Methods: Retrospective data analyses of patients with CS treated at Semmelweis University were performed. Comprehensive evaluations, including medical assessments, audiological measurements, otoneurological investigations, imaging, and ophthalmological examinations, were conducted on all patients.

Results: Between 1995 and 2022, five patients with CS were followed. The severity and timing of ear and ocular symptoms varied. Bilateral, asymmetric hearing impairment manifested as sudden sensorineural hearing loss, and all patients experienced loss of bilateral vestibular function. Various ophthalmological manifestations showed instability over time. Systemic corticosteroids were the first-line treatment, immunosuppressive therapy (methotrexate, cyclophosphamide, cyclosporin A), and biological treatment (infliximab, adalimumab) used as second- and third-line therapies. Eye symptoms of all five patients were controlled by medications. For hearing impairment, four patients were treated with cochlear implantation and achieved long-term stable speech perception. Hearing improvement was found in one patient by conservative therapy. One patient required reimplantation due to device failure, which was performed without complications.

Conclusion: Sudden hearing loss and vestibular attacks in young patients require thorough investigation and close follow-up. Early corticosteroid therapy or immunosuppressive and biological treatment can stabilize symptoms, including hearing levels. Early hearing rehabilitation with cochlear implants is crucial. Long-term follow-up indicates stable hearing levels and speech perception.

Multiple sclerosis (MS) is a chronic autoimmune disease and demyelinating disorder of the central nervous system (CNS) with diverse clinical presentations that can make the diagnosis challenging. In this case report, we describe a rare initial presentation of MS, mistaken for Type 1 diabetes mellitus (T1DM) impaired gastric motility. The patient is a 32-year-old female with a history significant for T1DM who presented with 3 days of intractable vertigo, nystagmus, and gait disturbance. She was discharged 2 days prior for intractable nausea and vomiting presumed to be due to impaired gastric motility called gastroparesis. There was no prior history of focal neurologic deficits. Her family history revealed extensive autoimmune diseases in multiple first-degree relatives. Physical examination suggested a peripheral lesion but could not rule out a central lesion. Magnetic resonance imaging (MRI) brain demonstrated white matter lesions in regions specific for MS. The patient experienced modest improvement with IV corticosteroids. Patients with T1DM have a threefold increase in the incidence of MS. While gastroparesis is an uncommon initial symptom of MS, this diagnosis should be considered, particularly when neurological deficits are present. This case underscores the importance of considering the enteric nervous system in patients with preexisting autoimmune conditions with new-onset neurological symptoms.

Background: Leukocytoclastic vasculitis (LCV) is a known hypersensitivity reaction to biologic agents, often linked to tumor necrosis factor-α (TNF-α)inhibitors. We present a rare case of LCV in a patient receiving tocilizumab, a monoclonal antibody directed against interleukin-6 (IL-6)receptor.

Case presentation: A 33-year-old Asian female with seropositive rheumatoid arthritis presented to the rheumatology clinic complaining of a new rash that started a few days after an infusion of tocilizumab. Her rheumatoid arthritis had been managed with upadacitinib for several years, which was discontinued due to persistent transaminitis. She was started on tocilizumab after a 4-month break from biologics. Following the first tocilizumab infusion, she recalled having transient fatigue and several red dots on her forearms and feet. A few days after the second infusion, she developed a purpuric rash on her lower extremities and forearms. Skin biopsy confirmed LCV. The rash resolved slowly in a month after discontinuation of tocilizumab and prescription of prednisone 20 mg daily. At her 3-month follow-up, the patient remained in remission, and her rheumatoid arthritis was uneventfully managed with abatacept.

Conclusions: While most cases of biologic-associated LCV are induced by TNF-α inhibitors, only two known cases of tocilizumab-induced hypersensitivity vasculitis have been published in the literature. Our case represents only the third reported instance in the literature, highlighting the need to raise awareness of tocilizumab as a potential cause of leukocytoclastic vasculitis and the importance of prompt recognition and management.

This case report describes a 67-year-old male who presented with a 2-month history of painless left eye redness and muffled hearing. Ophthalmologic examination revealed elevated intraocular pressure (IOP) and significant conjunctival injection without associated pain or visual disturbance. Blood was observed in Schlemm's canal (SC), and a thorough investigation for elevated episcleral venous pressure (EVP) was performed. Imaging, including magnetic resonance imaging (MRI) and cerebral angiogram, was unremarkable. A rheumatologic workup led to the diagnosis of granulomatosis with polyangiitis (GPA). The patient's ocular symptoms improved significantly with systemic steroid treatment. He was subsequently managed with rituximab and avacopan as per standard GPA therapy. This case highlights the importance of considering vasculitis in patients presenting with unexplained elevation of EVP, and painless scleritis, particularly when there are also extraocular complaints.

The ABO blood group is the most clinically relevant system in transfusion medicine. Approximately 20% of individuals with blood group A of European descent belong to a weak A subgroup, most commonly A₂, which may produce anti-A₁ antibodies. These antibodies are usually cold-reactive IgM and rarely cause hemolysis, but can occasionally be clinically significant when reactive at 37°C. We describe a pregnant woman with sickle cell disease (HbS/β⁰ thalassemia) and prior hyperhemolysis syndrome who developed a severe delayed hemolytic transfusion reaction (DHTR) after transfusion of A₁ red blood cells (RBCs). Anti-A₁ was identified posttransfusion, confirming her as a non-A₁ subtype. Notably, she also experienced hemolysis following group O red cell transfusion, consistent with hyperhemolysis. This case highlights the rare but serious potential of anti-A₁ to cause DHTR, particularly in high-risk populations, and underscores the importance of increased vigilance when managing transfusion in sickle cell disease.

IgG4-related disease (IgG4-RD) is a rare, progressive, and immune-mediated fibroinflammatory disorder that primarily affects middle-aged men and is more prevalent in Asian populations. Although extensively studied, its pathophysiology remains incompletely understood. This case report describes a 44-year-old male presenting with multiple abscesses and progressive inflammatory symptoms, ultimately diagnosed with IgG4-RD with musculoskeletal involvement. Imaging and histopathological evaluation confirmed osteolytic lesions and significant IgG4-positive plasma cell infiltration. Soft tissue tumors in IgG4-RD are exceptionally rare, further emphasizing the uniqueness of this case. The patient showed clinical improvement with corticosteroid therapy. This case highlights the importance of considering IgG4-RD in the differential diagnosis of soft tissue and bone lesions and underscores the need for a multidisciplinary diagnostic approach.

Anakinra, a recombinant interleukin-1 (IL-1) receptor antagonist, is effective in treating autoinflammatory conditions in children; however, it may elicit a hypersensitive reaction, thus requiring desensitization. We report a case wherein a novel intravenous Anakinra desensitization protocol was applied for a child with hypersensitivity and needle phobia. A 10-year-old girl with tumor necrosis factor receptor-associated periodic syndrome (TRAPS) and Anakinra hypersensitivity underwent a 12-step intravenous desensitization protocol at the Royal Hospital, Oman. Intravenous desensitization was successful without adverse events. Subsequent subcutaneous Anakinra administration was well tolerated without further hypersensitivity or inflammatory episodes. This case demonstrates successful intravenous desensitization against Anakinra in a child with TRAPS and needle phobia, thus enabling continued treatment. This approach may benefit others facing similar challenges and warrants further research.