Nationwide analysis of adult hospitalizations with hemophagocytic lymphohistiocytosis and systemic lupus erythematosus.

INTRODUCTION: Hemophagocytic lymphohistiocytosis (HLH) is a well-recognized complication of systemic lupus erythematosus (SLE). This study aims to characterize HLH with and without SLE in the US adult inpatient population. METHODS: We performed a retrospective study of HLH with and without SLE from the 2016-2019 National Inpatient Sample (NIS) database. We described the demographic characteristics of HLH with and without SLE. Multivariable analysis was performed to calculate odds ratios (OR) for in-hospital death. RESULTS: A total of 8690 hospitalizations had HLH. Of those 605 (7%) had SLE, and 8085 (93%) did not have SLE. Relative to the non-SLE group, the SLE group was younger, had more females, less whites, more African Americans, more Hispanics, and more Asian/Pacific Islanders. Over 60% of HLH with or without SLE had a concurrent infection. Sixty (9.9%) of HLH hospitalizations with SLE died compared to 1735 (21.5%) of those without SLE. Among HLH hospitalizations, multivariable analysis showed that age (OR 1.02; 95% C.I. 1.016-1.031), Charlson Comorbidity Index (OR 1.15; 95% C.I. 1.091-1.213), infections (OR 3.35; 95% C.I. 2.467-4.557), and leukemia/lymphoma (OR 1.46; 95% C.I. 1.112-1.905) had higher odds of in-hospital death. SLE did not increase the odds of death. CONCLUSIONS: Inpatients with both HLH and SLE were younger, had a higher proportion of racial/ethnic minorities, and were predominately female. One out of every 10 hospitalizations for HLH ended in death but SLE itself was not an independent risk factor for death. Concurrent infection was the variable most associated with HLH death. Key Points • HLH and SLE group were younger and had higher proportions of female and racial/ethnic minorities. • SLE was not an independent risk factor for death in HLH patients.

Hemophagocytic Lymphohistiocytosis Hospitalizations in Adults and Its Association With Rheumatologic Diseases: Data From Nationwide Inpatient Sample.

OBJECTIVE: Hemophagocytic lymphohistiocytosis (HLH) is a rare potentially fatal multisystem inflammatory condition that is often triggered by an underlying medical condition. Epidemiologic data of HLH in adults with rheumatologic diseases are limited. The aim of our study was to characterize HLH hospitalizations in the US adult population with a special focus on patients with concomitant rheumatologic diseases. METHODS: We conducted a medical records review of hospitalizations in the United States during 2016 and 2017 with a diagnosis of HLH. Hospitalizations were selected from the National Inpatient Sample. International Classification of Diseases, Tenth Revision codes were used to identify rheumatologic diseases. A multivariate logistic regression analysis was used to calculate adjusted odds ratios (ORadj) for the association of HLH and rheumatologic diseases. RESULTS: Seven hundred fifty hospitalizations had a principal billing diagnosis of HLH. The median age of our study population was 47.5 years, and males made up 55% of the population. Overall mortality was 17%, and the median length of stay was 12 days. Twenty-five percent of the HLH cases had a concomitant rheumatologic diagnosis. Multivariate logistic regression analysis showed systemic lupus erythematosus (SLE) with nephritis (ORadj, 5.7), SLE without nephritis (ORadj, 9.2), adult-onset Still disease (ORadj, 338.9), and ankylosing spondylitis (ORadj, 10.7) were significantly associated with HLH. CONCLUSIONS: This analysis represents the largest sample to date to assess HLH hospitalizations. Our study showed that SLE, adult-onset Still disease, and ankylosing spondylitis were strongly associated with HLH.

The Co-existence of Rheumatoid Arthritis and Granulomatosis With Polyangiitis: Two Cases and Review of the Literature.

Granulomatosis with polyangiitis (GPA) and rheumatoid arthritis (RA) have shared features including vasculitis, ocular inflammation, interstitial lung disease, and arthritis but existing evidence indicates they are distinct conditions. Interestingly, the co-existence of GPA and RA has been described in the literature. Herein, we report two cases of GPA developing in patients with underlying RA and examine the relationship between the two conditions. Two cases of GPA that developed in patients with preexisting RA are described in detail. Additionally, PubMed was searched for articles in English showing an association of RA and GPA using keywords "rheumatoid arthritis, and vasculitis, and Wegener's, and ANCA, and granulomatosis polyangiitis." In addition to our two cases of RA and GPA overlap, 14 reports were identified in PubMed library from 1970 to 2020. Most of the cases were females (14/16, 88%), and had RA as the initial diagnosis (15/16, 94%). The mean age of RA diagnosis was 45.5 years, the mean age of GPA diagnosis was 52 years and the mean interval between both diagnoses was 101 months. Cyclophosphamide and steroid therapy were used in most of the cases. There are numerous reports of GPA and RA overlap in the literature. GPA should be considered in the differential diagnosis when vasculitis develops in patients with RA.