This study conducted in a tertiary care hospital presents the baseline characteristics of patients with rheumatic diseases who were infected with SARS-CoV-2. Older patients with a mean age of 65.3 years were found to be at a higher risk of getting severe COVID-19 pneumonia, which is consistent with multiple previously reported studies. Data from the French RMD COVID-19 cohort reported that age was a risk factor for severe disease; only 11 patients between the age of 18 and 54 years developed severe COVID-19, while cases increased to 20 between the age of 65 and 74 years and to 45 in patients > 75 years . Furthermore, the mortality rate was higher in the elderly patients, as shown in a recent publication by the COVID-19 Global Rheumatology Alliance physician-reported registry, which found that 68.7% of those who died were > 65 years old .
Most of our study subjects were female (87.2%), which is consistent with the natural history of female predominance in autoimmune diseases. This reflects the higher percentage of females developing severe COVID-19 pneumonia (88.9%) and those who required invasive ventilation in our cohort. This is in contrast to multiple reported papers from different geographical areas [15, 16]. For instance, the COVID-19 Global Rheumatology Alliance physician-reported registry found that there was no significant difference in the rate of hospitalization based on sex . However, sex was not found to be a statistically significant factor for hospital admission or severity of the disease. In addition, we found a low prevalence of smoking in our subjects; however, none of the smokers developed severe COVID-19 pneumonia, which is not in line with a large meta-analysis by Patanavanich et al. who found that smoking was associated with poor prognosis . These differences could be due to the small sample size in our study and the low prevalence of female smokers in the Saudi culture.
In a study by Zhong et al., they traced patients with rheumatic diseases who lived with family members who were tested positive for SARS-CoV-2. They found that patients with rheumatic diseases had a higher predisposition for SARS-CoV-2 infection compared to other family members . Moreover, adjusted multivariable analysis by Freites Nuñez et al. for sex, age, and comorbidities associated with COVID-19 found that higher age and presence of autoimmune diseases had a higher probability of hospitalization, regardless of other factors . Furthermore, a comparative cohort study by D'Silva et al. found that a history of rheumatic disease was associated with an increased rate of invasive ventilation than the control group, though both had identical clinical features and rates of hospitalization . Nevertheless, no specific rheumatic disease was found to be a statistically significant risk factor for hospitalization or severity of the disease in our study. However, multivariate analysis in a study by Fernandez-Gutierrez et al. showed that some autoimmune diseases, namely Sjogren's syndrome, polychondritis, Raynaud, and MCTD, are associated with higher rates of hospital admissions . Among risk factors other than rheumatic diseases, the Brescia Rheumatology COVID-19 Study Group found no difference in the comorbidities between deceased or alive patients . In contrast, a recent review concluded that not only rheumatic diseases can affect COVID-19 outcome, but also the other comorbidities those patients have, which necessitates patients stratification based on the presence and number of comorbidities especially during the pandemic to aid in predicting outcome .
Our study showed that no specific DMARDs were associated with severe COVID-19 pneumonia, and none of them was found to be statistically significant, which is similar to the results of a study by Santos et al.  Likewise, another publication showed similar findings, wherein baseline rheumatic therapies did not alter the mortality rate . In contrast, the COVID-19 Global Rheumatology Alliance physician-reported registry found that biological DMARD/targeted synthetic DMARD monotherapy was associated with lower rates of hospital admissions . However, inferred results from a systematic review suggested that patients with rheumatic diseases on chronic immunosuppressive medications are more likely to require ICU admissions and invasive ventilation .
Among the COVID-19 symptoms, fever, myalgia, and cough were the most commonly reported symptoms by our patients (78.7%, 78.7%, and 74.5%, respectively), which is consistent with the report of a German registry .
During the early days of the pandemic with a lack of evidence-based knowledge about the course of COVID-19 and the prognosis in immunocompromised patients, one of our national policies was to admit all immunocompromised patients diagnosed with COVID-19 for close monitoring, regardless of their disease severity, resulting in a high admission rate in our study (48.9%). However, only 19.1% of these patients had severe COVID-19 pneumonia based on the WHO definition . Similarly, a high rate of admissions for such patients was reported in the literature, one of which was published by Freites Nuñez et al., who reported an admissions rate of 44%; however, our ICU admissions rate was higher . Few of our patients received experimental treatments for COVID-19, with dexamethasone being the most frequently prescribed drug after the release of preliminary findings of the RECOVERY trial .
Our cohort showed a significantly low rate of mortality (2.1%) compared to multiple studies worldwide reporting a mortality rate ranging from 6 to 19% [7, 20, 27]. The only deceased patient was an elderly female who was known to have RA and was on rituximab. She was one of the two patients-receiving rituximab as baseline DMARD for their rheumatic disease, which is reported to be associated with increased adverse events and high mortality rates in patients with COVID-19 . The patient’s hospital course was complicated with the development of cytokine release syndrome, for which she received an experimental tocilizumab dose and required invasive ventilation.
The following are a few limitations of our study. First, it was a single-centered study with small sample size. However, this is the first paper from our region addressing the baseline characteristics and clinical outcome of COVID-19 in patients with rheumatic diseases. The second limitation is the retrospective study design, which limits our ability to assess for rheumatic disease activity, as the patients were being managed and seen by non-rheumatologists during that COVID-19 illness. Moreover, they were isolated to minimize contact with multiple physicians. Finally, cumulative doses of steroids were not documented due to a lack of data.