Nomenclature and abbreviation heterogeneity in immune-mediated necrotizing myopathy: A call for standardization

Immune-mediated necrotizing myopathy (IMNM) is a distinct subtype of idiopathic inflammatory myopathies (IIMs). Despite its increasing recognition, considerable variability persists in its nomenclature, posing challenges for research comparability, clinical trial design, and patient care.

We conducted a scoping review of English-language publications from November 1974 to December 2023 to assess the diversity and trends in IMNM nomenclature and abbreviations. Articles were screened for IMNM terminology and abbreviations, and categorized by publication year, region, and study design. Descriptive statistics with temporal/geographic trend analyses were performed using SPSS.

Of 1236 articles identified, 626 met inclusion criteria, spanning 42 countries. Marked heterogeneity in terminology was observed. Regarding spelling, "necrotizing" (with "z") predominated (497 mentions) compared to "necrotising" (66 mentions), particularly after 2010 when usage of the "z" form rose sharply (463 vs. 60, respectively). For disease suffix, "myopathy" overwhelmingly replaced "myositis" in recent years (487 vs. 44 post-2010). Prefix terminology also evolved: "immune-mediated" became the dominant prefix (366 mentions post-2010) compared to "autoimmune" (91 mentions). Longitudinal analysis demonstrated that prior to 2010, terminology was inconsistent, but from 2010 onwards, coinciding with the ENMC classification, publications increasingly converged toward the standardized form immune-mediated necrotizing myopathy (IMNM). Antibody-based naming remained uncommon (7 %), and statin-associated descriptors were reported in 11 %. Abbreviations emerged in 2011, with IMNM now dominant (80 %) compared to NAM (13 %) and NM (6 %).

This review highlights a clear evolution and gradual consensus in IMNM nomenclature. Despite progress toward standardization, residual variability persists, underscoring the need for unified terminology to advance research, collaboration, and clinical care.