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Objective: Serum IgG4 concentrations are used to evaluate a diagnosis of IgG4-related disease (IgG4-RD), but the positive predictive value (PPV) of a very high IgG4 level is uncertain. This study evaluated the PPV of a very high IgG4 concentration for diagnosing IgG4-RD., Methods: The data warehouses of 2 large academic healthcare systems were queried for IgG4 concentration test results. Cases with serum IgG4 concentrations > 5× the upper limit of normal (ULN) were included. Cases of IgG4-RD were determined using the American College of Rheumatology/European Alliance of Associations for Rheumatology (ACR/EULAR) classification criteria. The PPV for IgG4-RD of an IgG4 concentration > 5× ULN was estimated. Other conditions associated with very high IgG4 concentrations and specific features of IgG4-RD cases were characterized., Results: IgG4 concentrations were available in 32,206 cases. Of these, 3039 (9.4%) had elevated IgG4 concentrations, and a final cohort of 191 (0.6%) cases had IgG4 concentrations > 5× ULN (median age 66 yrs, 72% male). The PPV of an IgG4 concentration > 5× ULN for a diagnosis of IgG4-RD was 75.4% (95% CI 68.7-81.3). In the remaining cases, elevated IgG4 concentrations were observed among patients with malignancies, autoimmune diseases, and infections., Conclusion: The majority of cases with serum IgG4 concentrations > 5× ULN in this study had IgG4-RD. These data support the high weight placed on very high serum IgG4 concentrations in the ACR/EULAR classification criteria. However, 25% of cases with very high IgG4 concentrations had an alternative diagnosis, underscoring the importance of considering the broad differential of etiologies associated with an elevated IgG4 concentration when evaluating a patient., (Copyright © 2023 by the Journal of Rheumatology.)

Objective: Patients with systemic autoimmune rheumatic diseases (SARDs) face illness-related uncertainty, but little is known about the psychological profiles and psychosocial and health needs associated with uncertainty among adults with SARDs., Methods: Patients from the Massachusetts General Hospital with antineutrophil cytoplasmic antibody-associated vasculitis (AAV), IgG4-related disease (IgG4-RD), and systemic sclerosis (SSc) completed the Mishel Uncertainty in Illness Scale, 8-item Patient Health Questionnaire depression scale, 7-item General Anxiety Disorder scale, Sickness Impact Profile, and a survey of psychosocial needs. The associations of uncertainty and self-reported needs with depression, anxiety, and sickness impact were assessed., Results: One hundred thirty-two patients with AAV (n = 41, 31%), IgG4-RD (n = 61, 46%), or SSc (n = 30, 23%) participated. The mean age was 64 years, 52% were female, and 83% were White. Greater illness-related uncertainty was positively correlated with higher levels of depression ( r = 0.43, P < 0.001), anxiety ( r = 0.33, P < 0.001), and sickness impact ( r = 0.28, P = 0.001). We observed variations in these measures across SARDs, such that uncertainty was more strongly associated with depression and sickness impact in AAV or SSc compared to IgG4-RD. The primary needs that patients endorsed were services for managing physical symptoms (53%), self-care (37%), and emotional concerns (24%), with greater needs strongly associated with greater illness-related uncertainty., Conclusion: Among patients with SARDs, illness-related uncertainty is correlated with levels of depression, anxiety, and sickness impact, as well as psychosocial needs. Findings also implicate the need for targeted interventions to address uncertainty and needs among subgroups of patients with different illness profiles., (Copyright © 2022 by the Journal of Rheumatology.)

Objective: The management of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) has evolved substantially over the last 2 decades. We sought to characterize AAV treatment patterns in the United States., Methods: We identified patients with AAV in the Rheumatology Informatics System for Effectiveness (RISE) registry who had at least 2 rheumatology clinician visits between January 1, 2015, and December 31, 2017. Demographics, medications, laboratory test results, and billing codes were extracted from the medical record. Demographic and prescription trends were assessed overall and across US regions., Results: We identified 1462 patients with AAV, 259 (18%) with new or relapsing AAV. The majority were classified as having granulomatosis with polyangiitis (75%). The mean age was 59.8 years and 59% were female. The majority of patients were in the South (45%) followed by the Mid-West (32%), West (12%), and Northeast (8%). Patients had a median of 3 visits and follow-up of 579 days. The most commonly prescribed medications during the study period were glucocorticoids (86%) followed by rituximab (45%), methotrexate (33%), azathioprine (32%), and mycophenolate mofetil (18%); cyclophosphamide (CYC) was rarely used (7%). At the most recent visits in RISE, 47% of patients were on glucocorticoids. Prescription trends were similar across regions., Conclusion: To our knowledge, this is the first study to evaluate the demographics and management of AAV by rheumatologists outside of major referral centers. Management strategies vary widely, but CYC is rarely used. These observations can be used to inform future research priorities. Additional studies are needed to characterize AAV severity in RISE as well as patient and provider treatment preferences., (Copyright © 2021 by the Journal of Rheumatology.)