Ophthalmic Surgery, Lasers and Imaging Retina

Brief Report 

Positive Auto-Antibody Activity With Retina and Optic Nerve in Smokers and Non-Smokers: The Controversy Continues

Eric K. Chin, MD; David R. P. Almeida, MD, MBA, PhD; Khoa V. Lam, MD; John L. Keltner, MD; Charles E. Thirkill, PhD

Abstract

Auto-antibodies assist with the diagnosis of ocular paraneoplastic syndromes and autoimmune ocular conditions; however, the frequency of positive test results as a possible precursor to future disease is unknown. The frequency of positive antibodies in heavy smokers who may be at risk for autoimmune-related retinopathy and optic neuropathy was evaluated. Serum antibody activity was evaluated through the use of Western blot reactions from pig retina and optic nerve extract. Fifty-one patients were included: 35 patients were smokers (average: 40.9 pack-year history) and 26 patients had no past smoking history. None of the patients had any visual complaints or known eye disease. Of the patients studied, 76.5% (39 patients: 18 smokers, 21 non-smokers) had positive antiretinal antibodies, and 19.6% (10 patients: 3 smokers, 7 non-smokers) had positive antioptic nerve antibodies. Anti-retinal antibodies were seen in a majority of randomly selected patients with and without a past smoking history. Anti-optic nerve bodies were less common, but more prevalent in those who never smoked. The specificity of these antibodies remains greatly uncertain and clinical correlation is warranted.

[Ophthalmic Surg Lasers Imaging Retina. 2015;46:1068–1070.]

Abstract

Auto-antibodies assist with the diagnosis of ocular paraneoplastic syndromes and autoimmune ocular conditions; however, the frequency of positive test results as a possible precursor to future disease is unknown. The frequency of positive antibodies in heavy smokers who may be at risk for autoimmune-related retinopathy and optic neuropathy was evaluated. Serum antibody activity was evaluated through the use of Western blot reactions from pig retina and optic nerve extract. Fifty-one patients were included: 35 patients were smokers (average: 40.9 pack-year history) and 26 patients had no past smoking history. None of the patients had any visual complaints or known eye disease. Of the patients studied, 76.5% (39 patients: 18 smokers, 21 non-smokers) had positive antiretinal antibodies, and 19.6% (10 patients: 3 smokers, 7 non-smokers) had positive antioptic nerve antibodies. Anti-retinal antibodies were seen in a majority of randomly selected patients with and without a past smoking history. Anti-optic nerve bodies were less common, but more prevalent in those who never smoked. The specificity of these antibodies remains greatly uncertain and clinical correlation is warranted.

[Ophthalmic Surg Lasers Imaging Retina. 2015;46:1068–1070.]

Introduction

Autoimmune-related retinopathy and optic neuropathy encompasses a spectrum of ocular (ie, retinal and optic nerve) diseases related to auto-antibodies associated with varying degrees of vision loss. There is a need to appreciate what is normal or baseline antibody activity to establish what actually represents a “disease-associated” reaction.1,2 Additionally, there is ongoing controversy regarding the ability of antiocular auto-antibodies to predict the development of primary malignancy in healthy individuals.3,4 It is unclear whether antibody reactions found in healthy patients warrant an investigation into primary malignancy, and if so, by what laboratory or imaging modality. Even more controversial is the management of these patients.5,6

Smoking is clearly one of the greatest risk factors for malignancy, and the association is most well-described between small-cell lung cancer and cancer-associated retinopathy.7,8 We therefore sought to compare the antiocular immunologic activity of randomly selected cigarette smokers with that of individuals who have never previously smoked. We report the frequency of antibody activity in these individuals with the most commonly reported disease-associated auto-ocular antibodies (Table 1).

Commonly Reported Auto-Antibodies Against Retina and Optic Nerve

Table 1:

Commonly Reported Auto-Antibodies Against Retina and Optic Nerve

Patients and Methods

Any patients who were otherwise healthy without subjective visual complaints or any actively treated eye disease were randomly selected to participate in this study. A one-time blood sample was obtained, and Western blot preparations of retina and optic nerve were prepared as described elsewhere.9 We recorded any antibody activity against those antigens listed in Table 1. Prior to data collection, the study received institutional review board/ethics committee approval. Informed consent was obtained in all patients included.

Results

A total of 51 randomly chosen patients from an academic tertiary care center were included: 35 were current or former cigarette smokers and 26 were non-smokers. Among the smoker group, there was an average 40.9 pack-years (range: 20 to 125 pack-years) of smoking history. There was no greater auto-antibody activity in the smoker group compared to the non-smokers group. A summary of the positive bands seen in our sample is found in Table 2.

Number of Patients who had Positive Western Blot Auto-Antibodies in Smokers Versus Non-Smokers Against the Retina and Optic Nerves

Table 2:

Number of Patients who had Positive Western Blot Auto-Antibodies in Smokers Versus Non-Smokers Against the Retina and Optic Nerves

Discussion

Western blots have proven to be useful in detecting abnormal antiretinal reactions in cancer patients who experience vision loss.10 However, it is uncertain what significance these reactions have in patients, like those included in our study, who have no visual complaints or any known eye disease. Our initial hypothesis was that heavy smoking leads to increased lung cancer and, therefore, greater risk for autoimmune-related retinopathy, optic neuropathy, and other paraneoplastic disease. Surprisingly, there was positive antibody reaction in both of our cohorts; however, there was no greater antiretinal activity in the smoker group compared to the non-smoker group. The exact reason for increased antibody activity in our control group is unknown; however, perhaps smoking suppresses the development of these antibodies.

Our results show that cigarette smoking is one of many variables that could result in positive auto-antibodies. In general, the Western blot procedure for auto-antibody detection clearly has limitations, and the results may vary by the species of donor tissue used for the assay (eg, pig vs. monkey vs. human cadaver).3 Pig was ideal for our study because of its cost, accessibility, and homogeneity for studying autoimmune reactions within the eye. Interestingly, there was an obvious bias toward auto-antibody activity at the 23 kD and 47 kD regions in non-smoking controls. Of note, any immunologic activity in the 23 kD region may or may not represent recoverin11 because other unidentified retinal antigens may share the same molecular weight (Table 1). Although six patients in our control group were found to have a positive antiretinal band in the 23 kD region, we were able to determine that none were reactive with the molecularly cloned recoverin. This sort of clone-specific confirmation is not routinely done and further supports the need to identify other retinal antigens of identical molecular weight that may lack any known disease association. Furthermore, pathologic auto-antibodies may bind to different epitopes of a given antigen compared to benign auto-antibodies.12 Regarding 47 kD, alpha-enolase is a component of glycolysis and it is expressed in all cells; this may be why it was found in a greater number of non-smokers. Our results reaffirm the uncertainty as to whether or not this represents a disease-associated antigen. Perhaps this is also why a wide spectrum of clinical presentations associated with anti-enolase retinopathy exists.13

We conclude that the detection of autoimmune reactions using Western blot reactions may for now be only a supplement to clinical findings, given the positive laboratory findings seen in both our smoker and non-smoker groups who lacked visual complaints or any known disease. A more specific and sensitive method of confirming each Western blot band should be performed to fully characterize the antigen(s) involved.

References

  1. Heckenlively JR, Ferreyra HA, Jayasundera T. Controversies of diagnosing autoimmune retinopathy. Arch Ophthalmol. 2010;128(1):147–148.
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  4. Grewal DS, Fishamn GA, Jampol LM. Autoimmune retinopathy and antiretinal antibodies: a review. Retina. 2014;34(5):827–845. doi:10.1097/IAE.0000000000000119 [CrossRef]
  5. Ferreyra HA, Jayasundera T, Khan NW, He S, Lu Y, Heckenlively JR. Management of autoimmune retinopathies with immunosuppression. Arch Ophthalmol. 2009;127(4):390–397. doi:10.1001/archophthalmol.2009.24 [CrossRef]
  6. Jampol LM, Fishman GA. Immunosuppression for autoimmune retinopathy. Arch Ophthalmol. 2009;127(4):573–575. doi:10.1001/archophthalmol.2009.51 [CrossRef]
  7. Thirkill CE, FitzGerald P, Sergott RC, Roth AM, Tyler NK, Keltner JL. Cancer-associated retinopathy (CAR syndrome) with antibodies reacting with retinal, optic-nerve, and cancer cells. N Engl J Med. 1989;321(23):1589–1594. doi:10.1056/NEJM198912073212307 [CrossRef]
  8. Polans AS, Witkowska D, Haley TL, Amundson D, Baizer L, Adamus G. Recoverin, a photoreceptor-specific calcium-binding protein, is expressed by the tumor of a patient with cancer-associated retinopathy. Proc Natl Acad Sci USA. 1995;92(20):9176–9180. doi:10.1073/pnas.92.20.9176 [CrossRef]
  9. Querques G, Thirkill CE, Hagege H, Soubrane G, Souied EH. Choroidal neovascularization associated with cancer-associated retinopathy. Acta Ophthalmol. 2010;88(5):571–575. doi:10.1111/j.1755-3768.2008.01456.x [CrossRef]
  10. Rahimy E, Sarraf D. Paraneoplastic and non-paraneoplastic retinopathy and optic neuropathy: evaluation and management. Surv Ophthalmol. 2013;58(5):430–458. doi:10.1016/j.survophthal.2012.09.001 [CrossRef]
  11. Thirkill CE, Tait R, Tyler NK, Roth AM, Keltner JL. The retinal CAR antigen is a recoverin-like protein. Invest Ophthalmol Vis Sci. 1992;33(10):2768–2772.
  12. Adamus G, Amundson D, Seigel GM, Machnicki M. Anti-enolase-alpha autoantibodies in cancer-associated retinopathy: epitope mapping and cytotoxicity on retinal cells. J Autoimmun. 1998;11(6):671–677. doi:10.1006/jaut.1998.0239 [CrossRef]
  13. Weleber RG, Watzke RC, Shults WT, et al. Clinical and electrophysiologic characterization of paraneoplastic and autoimmune retinopathies associated with antienolase antibodies. Am J Ophthalmol. 2005;139(5):780–794. doi:10.1016/j.ajo.2004.12.104 [CrossRef]

Commonly Reported Auto-Antibodies Against Retina and Optic Nerve

Molecular Weight (kD)Antigen Name/Description
20Retinal antigen associated with some cases of MAR and vision loss that occurs in other skin ailments, such as lupus.
22Cancer-associated neurotransmitter antigen expressed in both retina and optic nerve.
23Recoverin, associated with vision loss most commonly and described with small-cell lung carcinomas
30Carbonic anhydrase
40Rhodopsin, transducin-alpha, aldolase-C, GAPDH, and an unknown cancer-associated antigen expressed within the outer plexiform layer.
45PEDF
47Alpha-enolase
48–50S-antigen
55Vascular antigen associated with retinal vasculitis
56Retinal ganglion antigen found in some cases of open angle glaucoma
62CRMP-5 cancer-associated antigen expressed in both the retina and optic nerve
78TULP1
145IRBP

Number of Patients who had Positive Western Blot Auto-Antibodies in Smokers Versus Non-Smokers Against the Retina and Optic Nerves

Retina ReactionsOptic Nerve Reactions
Molecular Weight (kD)SmokersNon-SmokersSmokersNon-Smokers
200200
220000
230600
300000
408210
452000
472727
48–503100
552300
560000
620000
780000
1451000
Total Positive Bands182137
Authors

From the University of California Davis Eye Center, Sacramento, Calif. (EKC, KVL, JLK, CET); the University of Iowa, Department of Ophthalmology and Visual Sciences, Iowa City, Iowa (EKC, DRPA); Retina Consultants of Southern California, Riverside, Calif. (EKC); and VitreoRetinal Surgery, PA, Minneapolis (DRPA).

Supported in part by Research to Prevent Blindness.

The authors report no relevant financial disclosures.

Address correspondence: Eric K. Chin, MD, Retina Consultants of Southern California, 9041 Magnolia Ave., Suite 207; Riverside, CA 92503; email: chin.eric@gmail.com.

Received: February 26, 2015
Accepted: September 24, 2015

10.3928/23258160-20151027-17

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