ICAP
AC-25 - Spindle fibers
Previous Nomenclature None
Description The spindle fibers between the poles are stained in mitotic cells, associated with cone-shaped decoration of the mitotic poles. Spindle fibers cover both NuMA-like and non-NuMA patterns. NuMA-like pattern has associated distinct nuclear speckles. Only non-NuMA patterns are shown here while NuMA-like patterns are shown in the NuMA-like group.
Antigen Association HsEg5
Clinical Relevance
First level information
About Clinical Relevance & List of Abbreviations

The AC-25 pattern has low positive predictive value for any disease (109)

Found very infrequently in a routine serology diagnostic setting (109)

Antigen recognized includes HsEg5; specific immunoassays for this autoantibody, or other spindle fiber targets, are currently not commercially available (110, 111)

First level information references
109.
Mozo L, Gutiérrez C, Gómez J. Antibodies to mitotic spindle apparatus: clinical significance of NuMA and HsEg5 autoantibodies. J Clin Immunol 2008;28:285-90.
110.
Whitehead CM, Winkfein RJ, Fritzler MJ, et al. The spindle kinesin-like protein HsEg5 is an autoantigen in systemic lupus erythematosus. Arthritis Rheum 1996;39:1635-42.
111.
Szalat R, Ghillani-Dalbin P, Jallouli M, et al. Anti-NuMA1 and anti-NuMA2 (anti-HsEg5) antibodies: clinical and Immunological features: a propos of 40 new cases and review of the literature. Autoimmun Rev 2010;9:652-6.
Second level information

While AC-25 is not associated with a defined autoimmune disease, reactivity with HsEg5 is more commonly found in SjS and SLE (8, 9)

 

Note: Specific immunoassays for HsEg5 are currently not commercially available.

Second level information references
8.
Whitehead CM, Winkfein RJ, Fritzler MJ, et al. The spindle kinesin-like protein HsEg5 is an autoantigen in systemic lupus erythematosus. Arthritis Rheum 1996;39:1635-42.
9.
Szalat R, Ghillani-Dalbin P, Jallouli M, et al. Anti-NuMA1 and anti-NuMA2 (anti-HsEg5) antibodies: Clinical and immunological features: A propos of 40 new cases and review of the literature. Autoimmun Rev 2010;9:652-6.
FAQ
How to deal with just a “nuclear speckled” IFA report?
In my practice I have followed patients with ANA findings, with a nuclear speckled pattern (without specifying whether fine/dense/coarse), in patients with very heterogeneous phenotypes, some with a clinical picture that suggests further investigation of systemic autoimmune disease (one patient with proximal muscle weakness and skin thickening) and others who represent only non-specific findings. In such situations, as a precaution, I request more specific autoantibodies. However, this pattern (nuclear speckled pattern) is not described by the "ICAP" and I am in doubt about which antigenic association it represents, even to guide which autoantibody may be present and which ones to look after. How to interpret this pattern? Does the lab describe it when it is not possible to "refine" such a conclusion? Could this be associated with deficiency in the methodology, sample, interpretation?
 
 
Online since 19 May 2015