Comparison of current methods for anti-dsDNA antibody detection and reshaping diagnostic strategies.

Anti-double-stranded DNA antibodies (anti-dsDNA) are considered a specific marker for systemic lupus erythematosus (SLE). Though the Farr technique was once the reference method for their detection, it has been almost entirely replaced by more recently developed assays. However, there is still no solid evidence of the commutability of these methods in terms of diagnostic accuracy and their correlation with the Crithidia luciliae immunofluorescence test (CLIFT). Anti-dsDNA antibody levels were measured in 80 subjects: 24 patients with SLE, 36 disease controls drawn from different autoimmune rheumatic diseases (14 systemic sclerosis, 10 Sjögren's syndrome, nine autoimmune myositis, three mixed connective tissue disease), 10 inflammatory arthritis and 10 apparently healthy blood donors by eight different methods: fluorescence enzyme immunoassay, microdot array, chemiluminescent immunoassay (two assays), multiplex flow immunoassay, particle multi-analyte technology immunoassay and two CLIFT. At the recommended manufacturer cut-off, the sensitivity varied from 67% to 92%, while the specificity ranged from 84% to 98%. Positive agreement among CLIFT and the other assays was higher than negative agreement. Mean agreement among methods assessed by the Cohen's kappa was 0.715, ranging from moderate (0.588) to almost perfect (0.888). Evaluation of the concordance among quantitative values by regression analysis showed a poor correlation index (mean r2, 0.66). The present study shows that current technologies for anti-dsDNA antibody detection are not fully comparable. In particular, their different correlation with CLIFT influences their positioning in the diagnostic algorithm for SLE (either in association or sequentially). Considering the high intermethod variability, harmonization and commutability of anti-dsDNA antibody testing remains an unachieved goal.

Current technologies for anti-ENA antibody detection: State-of-the-art of diagnostic immunoassays.

BACKGROUND: Autoantibodies against extractable nuclear antigens (ENA) play a pivotal role in the diagnosis and classification of systemic autoimmune rheumatic diseases (SARD). In recent years, newly developed methods have enabled the simultaneous and quantitative detection of multiple anti-ENA reactivities. However, data regarding the comparability of results obtained using different technologies across different platforms are scarce. In this study we compared eight different immunoassays, commonly used in current laboratory practice for detection of anti-ENA antibodies. METHODS: Sixty patients suffering from different SARD, 10 inflammatory arthritis patients (disease controls) and 10 healthy blood donors were included in this comparative study. Sera were collected in 15 centers belonging to the Study Group on Autoimmune Diseases of the Italian Society of Clinical Pathology and Laboratory Medicine. We evaluated the analytical sensitivity, specificity and diagnostic accuracy of each method for antibodies to Sm, RNP, Ro60, Ro52, Scl70, CENP-B and Jo1. Cohen's kappa was used to analyze the agreement among methods. RESULTS: Average agreement among methods was 0.82, ranging from substantial (k = 0.72) to almost perfect (k = 0.92). However, while the specificity was very good for all methods, some differences emerged regarding the analytical sensitivity. CONCLUSIONS: Diagnostic performance of current technologies for anti-ENA antibody detection showed good comparability. However, as some differences exist among methods, laboratory scientists and clinicians must be aware of the diagnostic accuracy of the testing method in use.

Comparison of the Results of Proficiency Testing in Seven Medical Laboratories - a Benchmark Project to Define a Uniform Key Performance Indicator.

BACKGROUND: In medical laboratories, it is mandatory to ensure the analytical quality of the measurement procedures by proficiency testing (PT). The aim of this study was to evaluate whether the PT results of seven medical laboratories in South Tyrol - as a measure of the analytical performance - were different. METHODS: As a measure for the analytical performance of the individual laboratories, we used the PT results (RIQAS, Randox international quality assessment scheme) of one year for 34 analytes. We calculated annual 'total scores' of each analyte for all participating laboratories and compared them statistically. RESULTS: In 2018, there was a highly significant difference between the seven laboratories in the 'total scores' for the 34 analytes (p < 0.001). The laboratories had a 'cumulative, annual total score' of 75 - 91% of the maximum achievable values. Essentially, two groups could be distinguished. Laboratories 1 - 3 achieved better results (90 - 91%) than laboratories 4 - 7 (77 - 82%). In particular, the non-participation of the laboratories 4 - 7 in several PT cycles in 2018 and the registration in the wrong homogeneous group for some analytes in the laboratories 4 and 5 seem to be responsible for the worse results. CONCLUSIONS: The analytical performance as assessed by the PT results was different across the seven participating laboratories of the South Tyrolean Medical Service. Based on our study results, we defined a uniform key performance indicator for the seven laboratories with a limit value for the 'cumulative, annual total score' of > 80%.

Oral birch pollen immunotherapy with apples: Results of a phase II clinical pilot study.

BACKGROUND: Seventy percent of patients suffering from birch pollen allergy (BPA) develop a pollen-related food allergy (prFA), especially to apples, due to a clinically relevant cross-reactivity between the major allergen in birch Bet v 1 and Mal d 1 in apples. Therefore allergen-specific immunotherapy with fresh apples (AITA) could be a promising natural treatment of both BPA and prFA. OBJECTIVE: To assess the clinical efficacy of immunotherapy by daily apple consumption for patients with BPA and prFA. METHODS: A daily defined increasing amount of selected cultivars (Red Moon®, Pink Lady®, Topaz, Golden Delicious) was continuously consumed by 16 patients (12 female; median age; 50; range, 23-68 years), leading to increased intake of allergen over a period of at least 8 months. Specific IgE and IgG4 to Bet v 1 and Mal d 1, conjunctival and oral provocation tests, skin reactivity, and the average daily rhinoconjunctivitis combined symptom and medication score (CSMS) were measured during the peak birch pollen season. RESULTS: After 8 months of therapy, patients showed increased tolerance to apples (p < .001) and a decreased skin reactivity to apples. Oral allergy syndrome to other birch prFA than apple also decreased (p < .05). Moreover, daily rhinoconjunctivitis CSMS declined by 34% (p < .001), as did conjunctival reactivity to birch pollen extract by 27% (p < .01), while specific IgG4 to Mal d 1 and Bet v 1 increased (p < .01).

A new diagnostic algorithm for pattern-oriented autoantibody testing according to the ICAP nomenclature: A pilot study.

The commercial tests currently available as second-level tests to detect ANA sub-specificities are generally used independently from the ANA immunofluorescence (IIF) pattern. The aim of this study was to evaluate the efficacy of the use of a customizable pattern-oriented antigenic panel by immunoblot (IB) using the International Consensus on ANA Patterns (ICAP) classification scheme, in order to introduce a novel and updated autoimmune diagnostic flowchart. 710 sera referred for routine ANA testing were selected on the basis of the ANA pattern according to the ICAP nomenclature (nuclear speckled AC-2,4,5; nucleolar AC-8,9,10,29; cytoplasmic speckled AC-18,19,20) and on an IIF titer ≥1:320. They were then assayed by three experimental IB assays using a panel of selected antigens. ICAP-oriented IB detected 515 antibody reactivities vs. 457 of traditional anti-ENA in the nuclear speckled pattern group, 108 vs. 28 in the nucleolar pattern group, and 43 vs. 34 in the cytoplasmic speckled pattern. This pilot study may lead the way for a new approach introducing an ICAP pattern-oriented follow up testing as a valid alternative to the existing standard panels, thus enabling more patients with autoimmune rheumatic disease to be accurately diagnosed.

Sequential recruitment of study participants may inflate genetic heritability estimates.

After the success of genome-wide association studies to uncover complex trait loci, attempts to explain the remaining genetic heritability (h 2) are mainly focused on unraveling rare variant associations and gene-gene or gene-environment interactions. Little attention is paid to the possibility that h 2 estimates are inflated as a consequence of the epidemiological study design. We studied the time series of 54 biochemical traits in 4373 individuals from the Cooperative Health Research In South Tyrol (CHRIS) study, a pedigree-based study enrolling ten participants/day over several years, with close relatives preferentially invited within the same day. We observed distributional changes of measured traits over time. We hypothesized that the combination of such changes with the pedigree structure might generate a shared-environment component with consequent h 2 inflation. We performed variance components (VC) h 2 estimation for all traits after accounting for the enrollment period in a linear mixed model (two-stage approach). Accounting for the enrollment period caused a median h 2 reduction of 4%. For 9 traits, the reduction was of >20%. Results were confirmed by a Bayesian Markov chain Monte Carlo analysis with all VCs included at the same time (one-stage approach). The electrolytes were the traits most affected by the enrollment period. The h 2 inflation was independent of the h 2 magnitude, laboratory protocol changes, and length of the enrollment period. The enrollment process may induce shared-environment effects even under very stringent and standardized operating procedures, causing h 2 inflation. Including the day of participation as a random effect is a sensitive way to avoid overestimation.

Radioactive Merano SPA Treatment for Allergic Rhinitis Therapy.

Allergic rhinitis is a common nasal disorder with a high impact on quality of life, high social costs in therapies, and a natural development towards asthma. Pharmacological therapy is based on several genres of medications, of which intranasal corticosteroids are currently the most widespread. Thermal water treatment has traditionally been used as adjunctive treatment for chronic rhinitis and sinusitis. The present study was carried out to assess the clinical efficacy of nasal inhalation of radioactive oligomineral water vapours from the Merano hot spring and to compare it with the clinical efficacy of mometasone furoate nasal spray. A comparative prospective study was performed in 90 allergic patients treated at Merano hot springs: a group of 54 subjects treated with radioactive thermal oligomineral water and a control group of 36 subjects treated with mometasone nasal spray. Patients of both groups were assessed before and after treatment by Sino-Nasal Outcome Test questionnaire, active anterior rhinomanometry with flow and resistance monitoring, measurement of mucociliary transport time, and cytological examination of nasal brushing/scraping. The study showed that inhalation treatment with radioactive hydrofluoric thermal water for two weeks produces an objective clinical and cytological improvement in allergic patients, similar to that obtained with mometasone furoate nasal spray.

The impact of different sample matrices in delayed measurement of glucose.

OBJECTIVES: This study was designed to compare glucose values in serum or lithium-heparin samples immediately centrifuged with those paired specimens collected in tubes containing Naf-KOx and centrifuged and analyzed 2.5h after collection. METHODS: Three blood samples were drawn from 20 volunteers. Blood samples collected in tubes with and clot activator and gel separator but without anticoagulant (SST) as well as those collected in tubes containing Lithium-Heparin and gel separator were centrifuged within 30min and analyzed 2h thereafter. Blood samples drawn in tubes containing the glycolysis inhibitor NaF-KOx were centrifuged after 2.5h and then analyzed. RESULTS: The glucose median value was 4.72mmol/L in SST tubes, 4.67mmol/L in lithium-heparin and 4.44mmol/L in NaF-KOx tubes. The difference between SST and lithium-heparin tubes was not statistically or clinically significant, whereas that between SST and Naf-KOx tubes was both analytically and clinically meaningful, exceeding the current quality specifications for glucose measurement. CONCLUSIONS: The rapid centrifugation of blood collected in serum or lithium-heparin tubes with gel separator is seemingly more reliable for delayed measurement of glucose compared to the use of blood tubes containing NaF-KOx.

Evaluation of capillary haemoglobin determination for anaemia screening in blood donation settings.

BACKGROUND: An accurate assessment of hemoglobin (Hb) values before donation is unavoidable for safeguarding donors' safety and fulfilling the current specifications of Hb content in blood bags. This study was hence aimed to compare a finger-prick method for Hb measurement in capillary blood with Hb assessment in venous blood using a hematological analyser. MATERIALS AND METHODS: The study populations consisted in 1,014 consecutive blood donors, who had paired measurement of Hb values with HemoCue on capillary blood and UniCel DxH800 in venous blood. RESULTS: A significant overestimation was found with HemoCue compared to UniCel DxH800, but the correlation between methods was significant (comprised between 0.600 and 0.759; all p<0.01) and the bias always lower than the quality specifications. The prevalence of Hb values below the gender-specific thresholds for blood donation was also not significantly different (p=0.186). DISCUSSION: It can hence be concluded that the finger-prick method evaluated is a safe and reliable means for screening blood donors.

Fully-automated, chemiluminescence IgA and IgG anti-tissue transglutaminase (tTG) antibodies serum assays for the screening of celiac disease.

AIM: Celiac disease (CD) is a systemic immune-mediated enteropathy sustained by gluten ingestion in genetically susceptible subjects. The European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) has recently revised the diagnostic criteria, emphasizing the crucial role of serological testing in the diagnosis of this condition. This study was hence aimed to evaluate a new chemiluminescence assay for measuring anti-transglutaminase (tTG) and anti-endomysium (EMA) antibodies in a general population of unselected outpatients. MATERIALS AND METHODS: The IgA and IgG anti-tissue transglutaminase (tTG) antibodies (Quanta Flash® IgA and Quanta Flash® IgG tTG, Inova Diagnostics, San Diego, CA, USA) were measured with the fully-automated BIO-FLASH® analyzer (Inova Diagnostics) in serum samples of 727 consecutive patients without a diagnosis of CD. Data were compared with those of anti-endomysium antibody (EmA) obtained in the same population. RESULTS: A total of 96.4% samples display a negative concordance (anti-tTG negative and EMA negative), O% were positive for EMA and negative for anti-tTG IgA and IgG, 3.6% were both positive for tTG IgA and EMA, whereas 0.6% displayed discordant results (positive for anti-tTG and negative for EMA). The concordance (99%) and inter-rater agreement (Kappa Statistics, 0.943; p<0.001) between anti-tTG IgA and EmA antibodies were excellent, with sensitivity and specificity of 99% and 100%, respectively. CONCLUSION: The results of this study show that Quanta Flash® IgA assay alone may be regarded as a reliable approach for screening of CD, with no need to perform EMA detection.

Spurious elevation of serum potassium concentration measured in samples with thrombocytosis.

BACKGROUND: Several factors that can lead to falsely elevated values of serum. Thrombocytosis is one of these factors, since breakage or activation of platelets during blood coagulation in vitro may lead to spurious release of potassium. The purpose of the study was to evaluate to which extent the platelet count may impact on potassium in both serum and plasma. METHODS: The study population consisted of 42 subjects with platelets values comprised between 20 and 750×109/L. In each sample potassium was measured in both serum and plasma using potentiometric indirect method on the analyzer Modular P800 (Roche, Milan, Italy). Platelet count was performed with the hematological analyzer Advia 120 (Siemens, Milano, Italy). RESULTS: Significant differences were found between potassium values in serum and in plasma. A significant correlation was also observed between serum potassium values and the platelet count in whole blood, but not with the age, sex, erythrocyte and leukocyte counts in whole blood. No similar correlation was noticed between plasma potassium and platelet count in whole blood. The frequency of hyperkalemia was also found to be higher in serum (20%) than in plasma (7%) in samples with a platelet count in whole blood >450×109/L. CONCLUSIONS: The results of this study show that platelets in the biological samples may impact on potassium measurement when exceeding 450×109/L. We henceforth suggest that potassium measurement in plasma may be more accurate than in serum, especially in subjects with thrombocytosis.

Sample stability for complete blood cell count using the Sysmex XN haematological analyser.

BACKGROUND: Sample stability is a crucial aspect for the quality of results of a haematology laboratory. This study was conducted to investigate the reliability of haematological testing using Sysmex XN in samples stored for up to 24 h at different temperatures. MATERIALS AND METHODS: Haematological tests were performed on whole blood samples collected from 16 ostensibly healthy outpatients immediately after collection and 3 h, 6 h or 24 h afterwards, with triple aliquots kept at room temperature, 4 °C or 37 °C. RESULTS: No meaningful bias was observed after 3 h under different storage conditions, except for red blood cell distribution width (RDW) and platelet count (impedance technique, PLT-I) at 37 °C. After 6 h, meaningful bias was observed for mean corpuscular haemoglobin (MCH) and mean corpuscular volume (MCV) at room temperature, red blood cell (RBC) count, mean corpuscular haemoglobin concentration (MCHC), MCH, MCV and PLT-I at 4 °C, and RBC, RDW, MCHC, MCH and PLT-I at 37 °C. After 24 h, a meaningful bias was observed for MCHC, MCV, platelet count (fluorescent technique, PLT-F) and mean platelet volume (MPV) at room temperature, MCHC, MCV, PLT-I and MPV at 4 °C, and all parameters except RBC count and MPV at 37 °C. DISCUSSION: Great caution should be observed when analysing results of haematological tests conducted more than 3 h after sample collection.

Factors associated with B-lines after exposure to hypobaric hypoxia.

AIMS: Increased extravascular lung water (EVLW) is seen as B-lines on chest ultrasonography. In lowlanders ascending to altitude the time course, relationship with the patient's clinical status and factors affecting B-lines are still unclear. The aim was to monitor B-lines, clinical status and N-terminal B-type natriuretic peptide (NT-proBNP) during exposure to high altitude. METHODS AND RESULTS: Chest ultrasonography, blood samples, cardiovascular parameters, and signs and symptoms of high altitude pulmonary oedema (HAPE) were prospectively assessed in 19 participants at baseline and after ascent to 3830 m (9, 24, 48, 72 h, and 8 days) by blinded investigators. Potential confounding factors (e.g. altitude variations, physical effort) were minimized. Generalized estimating equations were used to analyse factors associated with B-lines. B-lines changed with exposure to altitude (P = 0.006) in a parabolic-like pattern within the first 72 h; 10 of 18 participants (55.6%) had >5 B-lines at 24 h. B-lines were correlated with the number of signs and symptoms (partial coefficient = 0.372, P = 0.001). B-lines were associated with time (P = 0.038), sex (P = 0.013), and SpO2 (P = 0.042), but not with NT-proBNP (P = 0.546). The participant with a clinical diagnosis of HAPE had 23 B-lines. CONCLUSION: B-lines during exposure to altitude seem to reflect the individual response to hypobaric hypoxia and represent clinically relevant alterations at high altitude, also in patients with HAPE. Similar to previous studies, our results support a non-cardiogenic aetiology of B-lines.

Automated antinuclear immunofluorescence antibody screening: a comparative study of six computer-aided diagnostic systems.

BACKGROUND: Indirect immunofluorescence (IIF) plays an important role in immunological assays for detecting and measuring autoantibodies. However, the method is burdened by some unfavorable features: the need for expert morphologists, the subjectivity of interpretation, and a low degree of standardization and automation. Following the recent statement by the American College of Rheumatology that the IIF technique should be considered as the standard screening method for the detection of anti-nuclear antibodies (ANA), the biomedical industry has developed technological solutions which might significantly improve automation of the procedure, not only in the preparation of substrates and slides, but also in microscope reading. METHODS: We collected 104 ANA-positive sera from patients with a confirmed clinical diagnosis of autoimmune disease and 40 ANA-negative sera from healthy blood donors. One aliquot of each serum, without information about pattern and titer, was sent to six laboratories of our group, where the sera were tested with the IIF manual method provided by each of the six manufacturers of automatic systems. Assignment of result (pos/neg), of pattern and titer was made by consensus at a meeting attended by all members of the research team. Result was assigned if consensus for pos/neg was reached by at least four of six certifiers, while for the pattern and for the titer, the value observed with higher frequency (mode) was adopted. Seventeen ANA-positive sera and six ANA-negative sera were excluded. Therefore, the study with the following automatic instrumentation was conducted on 92 ANA-positive sera and on 34 ANA-negative sera: Aklides, EUROPattern, G-Sight (I-Sight-IFA), Helios, Image Navigator, and Nova View. Analytical imprecision was measured in five aliquots of the same serum, randomly added to the sample series. RESULTS: Overall sensitivity of the six automated systems was 96.7% and overall specificity was 89.2%. Most false negatives were recorded for cytoplasmic patterns, whereas among nuclear patterns those with a low level of fluorescence (i.e., multiple nuclear dots, midbody, nuclear rim) were sometimes missed. The intensity values of the light signal of various instruments showed a good correlation with the titer obtained by manual reading (Spearman's rho between 0.672 and 0.839; P<0.0001 for all the systems). Imprecision ranged from 1.99% to 25.2% and, for all the systems, it was lower than that obtained by the manual IIF test (39.1%). The accuracy of pattern recognition, which is for now restricted to the most typical patterns (homogeneous, speckled, nucleolar, centromere, multiple nuclear dots and cytoplasmic) was limited, ranging from 52% to 79%. CONCLUSIONS: This study, which is the first to compare the diagnostic accuracy of six systems for automated ANA-IIF reading on the same series of sera, showed that all systems are able to perform very well the task for which they were created. Indeed, cumulative automatic discrimination between positive and negative samples had 95% accuracy. All the manufacturers are actively continuing the development of new and more sophisticated software for a better definition in automatic recognition of patterns and light signal conversion in end-point titer. In the future, this may avert the need for serum dilution for titration, which will be a great advantage in economic terms and time-saving.

Overcoming a "probable" diagnosis in antimitochondrial antibody negative primary biliary cirrhosis: study of 100 sera and review of the literature.

Serum anti-mitochondrial antibodies (AMA) are the serological hallmark of primary biliary cirrhosis (PBC), yet up to 15% of PBC sera are AMA negative at routine indirect immunofluorescence (IIF) while being referred to as "probable" cases. The diagnostic role of PBC-specific antinuclear antibodies (ANA) remains to be determined. We will report herein data on the accuracy of new laboratory tools for AMA and PBC-specific ANA in a large series of PBC sera that were AMA-negative at IIF. We will also provide a discussion of the history and current status of AMA detection methods. We included IIF AMA-negative PBC sera (n=100) and sera from patients with other chronic liver diseases (n=104) that had been independently tested for IIF AMA and ANA; sera were blindly tested with an ELISA PBC screening test including two ANA (gp210, sp100) and a triple (pMIT3) AMA recombinant antigens. Among IIF AMA-negative sera, 43/100 (43%) manifested reactivity using the PBC screening test. The same test was positive for 6/104 (5.8%) control sera. IIF AMA-negative/PBC screen-positive sera reacted against pMIT3 (11/43), gp210 (8/43), Sp100 (17/43), both pMIT3 and gp210 (1/43), or both pMIT3 and Sp100 (6/43). Concordance rates between the ANA pattern on HEp-2 cells and specific Sp100 and gp210 ELISA results in AMA-negative subjects were 92% for nuclear dots and Sp100 and 99% for nuclear rim and gp210. Our data confirm the hypothesis that a substantial part of IIF AMA-negative (formerly coined "probable") PBC cases manifest disease-specific autoantibodies when tested using newly available tools and thus overcome the previously suggested diagnostic classification. As suggested by the recent literature, we are convinced that the proportion of AMA-negative PBC cases will be significantly minimized by the use of new laboratory methods and recombinant antigens.

Clinical aspects, diagnostic challenges and management of patients with neuroendocrine tumors (NETs).

Neuroendocrine tumor (NET) entities are rare malignancies. Higher awareness and improved diagnostic methods have led to an increasing incidence of these diseases, and most oncologists deal with such patients in their daily practice. The symposium on NETs that was held in Merano (Italy) in October 2009 was organized by the German-speaking European School of Oncology (dESO) and gathered specialists from different disciplines of transalpine countries to bring together experiences and observations regarding these tumors. The goal of the meeting and of this review was to illustrate both well- and poorly differentiated NETs and to encourage interdisciplinary approaches.

Antibodies to the lens and cornea in anti-DFS70-positive subjects.

Autoantibodies against DFS70 (dense fine speckles 70) antigen have recently been identified among antinuclear antibodies (ANA) in patients with various inflammatory diseases and in patients with different types of cancer. These antibodies are recognized using indirect immunofluorescence (IIF) on HEp-2 cells, by a fine speckled nuclear staining in interphase HEp-2 cells and a positive reaction in the chromosome region of mitotic cells. Given that the DFS70 protein is also known as the lens epithelium-derived growth factor, this study was performed with two objectives: (a) to assess the prevalence of these antibodies in patients sent for ANA testing and in 334 patients with different types of neoplasia and (b) to determine whether the lens tissue was a suitable substrate for the detection of antibodies specific to lens proteins. During routine workup for ANA detection by the IIF method, we found 172 DFS70-positive sera among 21,516 consecutive samples (prevalence, 0.8%). In the group of patients with neoplastic disease, 6 of 334 (1.8%) were anti-DFS70-positive. DFS70-positive sera were then assayed by the IIF method on cryostatic sections of mouse eye at a dilution of 1:40 with an anti-human IgG conjugate. Among the 172 DFS70-positive samples detected by the ANA screening, 32 (19%) were strongly reactive against the reticular fibers of the lens; 8 (5%) were positive only to the corneal epithelium (nuclear negative); 5 (3%) were positive both for the cornea and the lens fibers; 13 (7%) stained only the nuclei of lens and cornea cells, and 4 (2%) were positive against the ciliary muscle. Among the patients with neoplastic diseases, only one with lung cancer reacted weakly with the reticular fibers of the lens. Sera from 20 healthy blood donors were negative. In this preliminary study, we have shown that the prevalence of anti-DFS70 antibodies is much lower than previously reported, both in patients screened for ANA and in patients with cancer. We have also seen that some DFS70-positive sera have antibodies that recognize antigens of the lens. Further studies are needed to investigate the fine specificity and the possible significance of these new autoantibodies.