First Report of Two Cases of Löfgren’s Syndrome after SARS-CoV-2 Vaccination-Coincidence or Causality?

Sarcoidosis can present as an acute form or take a chronic course. One of the acute presentations is Löfgren’s syndrome (LS), consisting of the symptom triad of bilateral hilar lymphadenopathy, erythema nodosum, and ankle periarthritis. In addition, there are occasional reports of sarcoid-like reactions following drug exposures. Nevertheless, reports of sarcoidosis or LS after vaccination have not been published. Here, we report two cases of de novo LS in a temporal association with different vaccines against the new coronavirus SARS-CoV-2. One patient developed the first symptoms three days after the second vaccination (first vaccination ChadOx-1, Astra Zeneca; second vaccination CX-024414, Moderna); in the second patient, symptoms started 28 days after the first vaccination (ChadOx-1, Astra Zeneca). Both patients eventually required treatment with glucocorticoids. Both patients achieved clinical improvement with treatment. In conclusion, we report the first two cases of LS shortly after SARS-CoV-2 vaccination.

Lofgren’s syndrome: A case report and review of the literature

Lofgren’s syndrome is a variant of acute-onset sarcoidosis, characterized as Hilar Lymphadenopathy (HL), Erythema Nodosum (EN) and bilateral arthritis or arthralgia, with elevated serum Angiotensin Converting Enzyme (ACE) and calcium level. It is relatively common in Caucasians, but rarely reported in Asian countries. We reported a 72-year old Chinese female with HL, acute onset EN, multiple arthritis and arthralgia, and achieved remission with prednisolone treatment. We summarized reported cases in European and Asia countries, and investigated the characteristics of etiology, genetics, prognosis and therapeutic strategy variants due to different ethnicities. Almost all the patients showed HL, and half of them exhibited classical triad. ACE, the biomarker of Lofgren’s syndrome, elevated in more than half of the European cases, but only 30% in Asian patients. NASID is considered as the first choice of Lofgren’s syndrome, and glucocorticoid may be necessary in severe cases. One quarter of the cases from European countries need steroid therapy. However, the proportion is much higher (64.3%) to achieve symptomatic relief. Considering Lofgren’s syndrome is rare and less recognized from sarcoidosis in Asian patients, further investigation is needed to achieve clinical experience. Keywords: lofgren’s syndrome; lymphadenopathy; erythema nodosum; arthritis; sarcoidosis.

A fungal antigenic driver for Löfgren’s syndrome sarcoidosis

Löfgren’s syndrome is an acute form of sarcoidosis that is characterized by the activation of CD4+ T helper cells. In this issue of JEM, Greaves et al. (2021. J. Exp. Med.https://doi.org/10.1084/jem.20210785) identified a peptide derived from an airborne mold species that stimulates T cells of Löfgren’s syndrome patients in an HLA-DR3–restricted manner. An increased serum IgG antibody response to the full-length protein was also observed in those patients, indicating that the fungus Aspergillus nidulans might be the elusive microbial agent that drives acute sarcoidosis.

Pulmonary Sarcoidosis: Diagnosis and Differential Diagnosis

Sarcoidosis is a multisystem disorder of unknown origin and poorly understood pathogenesis that predominantly affects lungs and intrathoracic lymph nodes and is characterized by the presence of noncaseating granulomatous inflammation in involved organs. The disease is highly heterogeneous and can mimic a plethora of other disorders, making diagnosis a challenge even for experienced physicians. The evolution and severity of sarcoidosis are highly variable: many patients are asymptomatic and their disease course is generally benign with spontaneous resolution. However, up to one-third of patients develop chronic or progressive disease mainly due to pulmonary or cardiovascular complications that require long-term therapy. The diagnosis of sarcoidosis requires histopathological evidence of noncaseating granulomatous inflammation in one or more organs coupled with compatible clinical and radiological features and the exclusion of other causes of granulomatous inflammation; however, in the presence of typical disease manifestations such as Löfgren’s syndrome, Heerfordt’s syndrome, lupus pernio and asymptomatic bilateral and symmetrical hilar lymphadenopathy, the diagnosis can be established with high level of certainty on clinical grounds alone. This review critically examines the diagnostic approach to sarcoidosis and emphasizes the importance of a careful exclusion of alternative diagnoses.

CD4+ T cells in the lungs of acute sarcoidosis patients recognize an Aspergillus nidulans epitope

Löfgren’s syndrome (LS) is an acute form of sarcoidosis characterized by a genetic association with HLA-DRB1*03 (HLA-DR3) and an accumulation of CD4+ T cells of unknown specificity in the bronchoalveolar lavage (BAL). Here, we screened related LS-specific TCRs for antigen specificity and identified a peptide derived from NAD-dependent histone deacetylase hst4 (NDPD) of Aspergillus nidulans that stimulated these CD4+ T cells in an HLA-DR3–restricted manner. Using ELISPOT analysis, a greater number of IFN-γ– and IL-2–secreting T cells in the BAL of DR3+ LS subjects compared with DR3+ control subjects was observed in response to the NDPD peptide. Finally, increased IgG antibody responses to A. nidulans NDPD were detected in the serum of DR3+ LS subjects. Thus, our findings identify a ligand for CD4+ T cells derived from the lungs of LS patients and suggest a role of A. nidulans in the etiology of LS.

A Polymorphism in C-C Chemokine Receptor 5 (CCR5) Associates with Löfgren’s Syndrome and Alters Receptor Expression as well as Functional Response

C-C chemokine receptor 5 (CCR5) and polymorphisms in CCR5 gene are associated with sarcoidosis and Löfgren’s syndrome. Löfgren’s syndrome is an acute and usually self-remitting phenotype of sarcoidosis. We investigated whether the single nucleotide polymorphism (SNP) rs1799987 is associated with susceptibility for Löfgren’s syndrome and has an effect on CCR5 expression on monocytes and function of CCR5. A total of 106 patients with Löfgren’s syndrome and 257 controls were genotyped for rs1799987. Expression of CCR5 on monocytes was measured by flowcytometry. We evaluated calcium influx kinetics following stimulation upon N-formylmethionyl-leucyl-phenylalanine (fMLP) and macrophage inflammatory protein-1α (MIP-1α) on monocytes by measuring the median fluorescence intensity (MFI). The frequency of the G allele of rs1799987 was significantly higher in Löfgren’s syndrome than in healthy controls (p = 0.0015, confidence interval (CI) 1.22–2.32, odds ratio (OR) 1.680). Patients with a GG genotype showed higher CCR5 expression on monocytes than patients with the AA genotype (p = 0.026). A significantly (p = 0.027) lower count of patients with the GG genotype showed a calcium influx reaction to simulation upon MIP-1 α, compared with patients with the AA genotype. The rs1799987 G allele in CCR5 gene is associated with susceptibility to Löfgren’s syndrome and with quantitative and qualitative changes in CCR5, potentially effecting the inflammatory response.

Acute arthritis, skin rash and Lofgren’s syndrome

Sarcoidosis is an autoimmune multisystem granulomatous disorder of unknown aetiology, which mainly affects the adults in the age group of 20–39 years. The disease can affect any organ in the body but mainly presents as bilateral hilar lymphadenopathy, pulmonary infiltrates, cutaneous lesions, ocular manifestations and arthropathy. Lofgren’s syndrome is an uncommon initial presentation of sarcoidosis which is recognised by the classical triad of acute arthritis, erythema nodosum and bilateral hilar lymphadenopathy. We describe a newly diagnosed case of sarcoidosis who presented as Lofgren’s syndrome. Acute sarcoid arthritis should be kept as one of the differential diagnoses for patients presenting with acute arthritis and skin lesions; and chest X-ray should be considered to rule out bilateral hilar lymphadenopathy in these patients. Early suspicion and identification of classical clinical features are essential to establish early diagnosis.