Retrospective evaluation of "Rods and Rings" pattern detected in the anti-nuclear antibody (ANA) indirect immunofluorescence (IIF) test.

Introduction: Anti-rods and rings (anti-RR) antibodies have recently been described as a cytoplasmic pattern in IIF-based screening of autoantibodies on HEp-2 cells and ICAP has named it as AC-23. It is most frequently related to drug-induced antibody generation. This study aimed to investigate the clinical significance of AC-23 positivity and its relevance to the diagnosis and/or follow-up of the associated diseases and/or drug use. Methods: A multicenter retrospective study was conducted among 10 hospitals from six different provinces in Türkiye from January 2017 to December 2021. The laboratory data and clinical information of 600 patients with positive anti-RR antibodies out of 547.558 HEp-2 IIF ANA samples were analyzed. Results: The distribution of AC-23 positive patients by year indicated a steady increase between 2017-2021. Anti-RR prevalence in post-COVID-19 period was significantly higher than that of pre-COVID-19 period (p=0.00). Concomitant ANA positivity was detected in 56.5% of patients, the most common patterns being AC-4 and AC-5 (41.1%). The most frequent pathology among the anti-RR positive patients was an autoimmune disease (19.83%); 28.57% of which had rheumatoid arthritis and 17.65% autoimmune liver disease. Among the 600 patients, 65 (10.83%) were diagnosed as hepatitis C virus (HCV) infection. Available data for 38 of the HCV patients revealed that 71.05% of them had a history of interferon alfa+ribavirin and 28.95% of them had a history of NS3/4/5A/5B polymerase inhibitor or protease inhibitor drug use. Significant increase in the rate of anti-RR positivity was observed in the post-COVID-19 period when compared to pre-COVID-19 period (p:0.00). Discussion: This is the first multicenter study in Türkiye about the clinical association of anti-RR antibodies which may be ignored during routine HEp-2 IIF testing. Pathologies other than HCV should be taken into consideration in terms of the possible role of anti-RR in autoimmune diseases and other pathologies. The preliminary data obtained in this study suggest that anti-RR antibody development might also be associated to COVID-19, supporting the several previous data related to the potential of viruses triggering the formation of autoantibodies. Large-scale prospective studies should elucidate the clinical significance of RR pattern and determine its role in patient diagnosis and follow-up.

[Frequency of Influenza, Influenza Types and Influenza Vaccine Use in Hospitalized Children with Influenza-Like Symptoms]. / Grip Benzeri Sikayetler ile Hastaneye Yatirilan Çocuklarda Influenza Sikligi, Influenza Tipleri ve Influenza Asisi Kullanimi.

Influenza is an important cause of respiratory illness in children and is still an important cause of morbidity and mortality in children. The influenza virus subtypes determine the prevalence of the epidemic and pandemic influenza, the hospitalization and mortality rates in children each year. Surveillance of the circulation of different influenza virus strains is important in ensuring a good strain con-cordance for the composition of the annual influenza vaccine. The Global Influenza Hospital Surveillance Network® (GIHSN) is an international institution in which tertiary hospitals from many countries participate and where epidemiological surveillance of influenza disease is conducted. Six centers from Turkey participated in the study organized by GIHSN during the influenza season 2016 2017. The aim of this study was to demonstrate the frequency of influenza, virus types, clinical characteristics and vaccination rates in children admitted to our hospital with influenza-like symptoms in the influenza season 2016-2017. Informed consents were obtained from patients. 217 pediatric patients were screened with in the 24th and 48th hours of the hospitalization. Then a nasal/nasopharyngeal swab were collected from 184 patients who met the inclusion criteria. Real-time reverse-transcription polymerase chain reaction (rRT-PCR) was used to obtain laboratory results. Influenza virus, influenza virus subtypes were studied by rRT-PCR. The 83.3% of the patients with positive influenza was under 5 years of age. The rate of influenza positivity was 16.3% (n= 30 patients). Influenza A (H3N2) was the predominant strain in children. The 70% of isolates were influenza A (H3N2) and the 30% were influenza B (Yamagata). There were no case of influenza A (H1N1) or influenza B (Victoria). In 30% of cases with influenza positivity, there was an underlying disease. The most prevalent of them were neuromuscular disease followed by cardiovascular disease and asthma. Tobacco exposure was 86.6% in influenza positive cases. The empirical oseltamivir prescription rate was 28.2%. The vaccination rate of the influenza vaccine was very low (1.6%). The out of 3 patients with influenza positivity were admitted to pediatric intensive care unit, and 2 of them required mechanical ventilation. None of these patients required extracorpereal membrane oxygenation and did not die. Our results highlight the importance of surveillance for influenza and in particular, influenza vaccination rates of groups with risk for morbidity and mortality, such as children, need to be increased.