Israel Medical Association Journal

Background: Acute myocarditis (AM) is an inflammatory cardiac condition with heterogeneous clinical manifestations that often overlap with other acute cardiac syndromes, making diagnosis challenging.

Objectives: To characterize the prevalence, clinical profile, and outcomes of AM patients with respiratory viral pathogen detection on nasopharyngeal swabs at admission.

Methods: We retrospectively analyzed all patients admitted to the Sheba Medical Center with confirmed AM between January 2005 and December 2020. Diagnosis was based on compatible presentation, elevated cardiac biomarkers, and supportive imaging findings. Nasopharyngeal swab results, when performed, were reviewed for respiratory viral detection.

Results: Among 425 identified AM cases, 146 (34%) underwent swab testing; 11 (8%) tested positive for respiratory viral pathogens, most commonly influenza A (n=5) and adenovirus (n=3). With one exception, all positive cases occurred during winter or early spring (10/77, 13%). Compared with swab-negative patients, swab-positive individuals were older (47 ± 22 vs. 35 ± 14 years, P = 0.03), more frequently female (45% vs. 14%, P = 0.007), and more often presented with dyspnea (55% vs. 25%, P = 0.036) but less commonly with ST-segment elevation (27% vs. 70%, P = 0.003). No differences were observed in inflammatory markers, imaging findings, or hospital stay.

Conclusions: Respiratory viral detection in AM is uncommon and predominantly seasonal. Nasopharyngeal swabbing is a simple, non-invasive tool that may help identify treatable viral pathogens and guide patient management. These data provide a pre-COVID-19 reference for future studies investigating the impact of viral infection on myocardial injury.

Serum rheumatoid factors are autoantibodies of different isotypes directed against the Fc fraction of immunoglobulin G (IgG) and represent paradigmatic autoantibodies that have been largely used in clinical practice for decades. Traditionally IgG has been associated with rheumatoid arthritis and more recently included also in the classification criteria for Sjӧgren’s syndrome. Researchers have established that rheumatoid factors are positive in a variety of infectious, autoimmune, and neoplastic disorders, thus requiring a comprehensive evaluation of seropositive patients. Of note, hepatitis B and C viruses represent a crossroad that includes the high rheumatoid factor seroprevalence and chronic inflammatory disease, as well as progression to non-Hodgkin's lymphomas. Chronic antigen stimulation is the likely common ground of these processes and rheumatoid factors may represent mere bystanders or drivers of pathology. Mixed cryoglobulinemia and lymphoproliferative disease are prime examples of the deleterious effects of rheumatoid factor-B cell activity, possibly associated with hepatitis B and C. More importantly, they show a clear association in a physiological host response to infection, chronic inflammation, and the slide toward autoimmunity and malignancy. The association between hepatitis B and C infections and the appearance of serum rheumatoid factors is further supported by prevalence data, which support a coexistence of these markers in a significant proportion of cases, with viral infections being frequent causes of rheumatoid factors in patients without a rheumatic condition. We provide a comprehensive overview of the known connections between hepatitis B and C infections and rheumatoid factors.

The DRESS syndrome (drug reaction with eosinophilia and systemic symptoms), also known as DIHS (drug-induced hypersensitivity syndrome), presents clinically as an extensive mucocutaneous rash, accompanied by fever, lymphadenopathy, hepatitis, hematologic abnormalities with eosinophilia and atypical lymphocytes, and may involve other organs with eosinophilic infiltration, producing damage in several systems, especially kidney, heart, lungs, and pancreas. The pathogenesis is related to specific drugs (especially the aromatic anticonvulsants), altered immune response, sequential reactivation of herpes virus, and association with some HLA alleles. Glucocorticoids are the basis for the treatment of the syndrome, which may be given with intravenous immunoglobulin and, in selected cases, ganciclovir. This article reviews current concepts regarding the interaction of drugs, viruses and immune responses during this complex adverse-drug reaction.