Serum vitamin D levels can be predictive of psoriasis flares up after COVID-19 vaccination: a retrospective case control study.

Introduction: Many patients with chronic inflammatory dermatosis such as psoriasis usually ask about the safety of COVID-19 vaccination and if it would affect the course of their disease. Indeed, many case reports, case series and clinical studies, reporting psoriasis exacerbation following vaccination against COVID-19, were published during the pandemic. Also, many questions arise regarding the existence of exacerbating factors of these flare ups, including environmental triggers such as the insufficiency of vitamin D levels. Methods: This is a retrospective study that measures alterations in psoriasis activity and severity index (PASI) not exceeding 2 weeks after the first and second dose of COVID-19 vaccinations in the reported cases and assesses whether such changes have any association with patients' vitamin D levels. We retrospectively reviewed the case records of all patients with a documented flare up after COVID-19 vaccination in our department as well as those who did not, during a year. Results: Among them, we found 40 psoriasis patients that had reported vitamin D levels in the form of 25-hydroxy-vitamin D within 3 weeks after vaccination, including 23 with exacerbation and 17 without exacerbation. Performing χ2 and t-test controls for psoriasis patients with and without flare-ups, a statistically significant dependence emerged in the seasons of summer [χ2(1) = 5.507, p = 0.019], spring [χ2(1) = 11.429, p = 0.001] and in the categories of vitamin D [χ2(2) = 7.932, p = 0.019], while the mean value of vitamin D for psoriasis patients who did not have exacerbation (31.14 ± 6.67 ng/mL) is statistically higher [t(38) = 3.655, p = 0.001] than the corresponding value of psoriasis patients who had an exacerbation (23.43 ± 6.49 ng/mL). Discussion: This study indicates that psoriasis patients with insufficient (21-29 ng/mL) or inadequate (<20 ng/mL) levels of vitamin D are more prone to postvaccination aggravation of the disease while vaccination in summer, a period with the most extent photo-exposition, can be a protective factor.

Diagnostic and clinical significance of antigen-specific pancreatic antibodies in inflammatory bowel diseases: A meta-analysis.

BACKGROUND: Non-invasive criteria are needed for Crohn's disease (CD) diagnosis, with several biomarkers being tested. Results of individual diagnostic test accuracy studies assessing the diagnostic value of pancreatic autoantibodies-to-glycoprotein-2 (anti-GP2) tests for the diagnosis of CD appear promising. AIM: To systematically review and meta-analyze evidence on the diagnostic accuracy of anti-GP2 tests in patients with suspected/confirmed CD. METHODS: An electronic search was conducted on PubMed, Cochrane-CENTRAL and grey literature (CRD42019125947). The structured research question in PICPTR format was "Population" including patients with symptoms akin to CD, the "Index test" being anti-GP2 testing, the "Comparator" involved standard CD diagnosis, the "Purpose of test" being diagnostic, "Target disorder" was CD, and the "Reference standard" included standard clinical, radiological, endoscopical, and histological CD diagnostic criteria. Quality was assessed with the Quality Assessment of Diagnostic Accuracy Studies-2 tool and hierarchical models were employed to synthesize the data. RESULTS: Out of 722 studies retrieved, 15 were meta-analyzed. Thirteen studies had industry-related conflicts-of-interest, and most included healthy donors as controls (spectrum bias). For the combination of IgA and/or IgG anti-GP2 test, the summary sensitivity was 20% (95% confidence interval: 10%-29%) at a median specificity of 97%. If the test was applied in 10000 suspected patients, 9669 would be true negatives and in 26, the diagnosis would be missed. In this hypothetical cohort, the anti-GP2 would fail to produce a diagnosis for 81.3% of the positive cases. Low summary points of sensitivity and high specificity were estimated for the IgG or IgA anti-GP2 test. Analogous results were observed when the analyses were restricted using specific cut-offs, or when ulcerative colitis patients were used as comparators. CONCLUSION: Anti-GP2 tests demonstrate low sensitivity and high specificity. These results indicate that caution is required before relying on its diagnostic value. Additionally, the need for improving the methodology of diagnostic test accuracy studies is evident.

Antimitochondrial antibodies of immunoglobulin G3 subclass are associated with a more severe disease course in primary biliary cirrhosis.

BACKGROUND/AIMS: Primary biliary cirrhosis (PBC) is characterised by the presence of immunoglobulin (Ig) G antimitochondrial antibodies (AMA), which are routinely detected by indirect immunofluorescence (IFL) using composite rodent tissue substrate. The IgG subclass distribution and clinical significance of IFL-detected AMA in patients with PBC have not been previously studied in detail. METHODS: We have examined IgG subclass-specific AMA detected by IFL on rodent liver, kidney and stomach tissue substrate using affinity-purified IgG subclass monospecific antisera as revealing reagents in 95 AMA-positive PBC patients from Greece. RESULTS: AMA of any of the IgG1, IgG2 or IgG3 subclasses were present in 89/95 (93.7%) patients. Among those 89, 55 (61.8%) had IgG1, 2, 3 AMA positivity; eight (9%) had IgG1, 2; seven (7.9%) had IgG2, 3; eight (9%) had IgG1, 3; nine (10.1%) had IgG1 subclass and two (2.2%) single IgG3 AMA reactivity. IgG4 AMA was absent. IgG3 titres were higher than IgG2 and IgG1 (P<0.001) and IgG1 higher than IgG2 (P<0.001). IgG3 AMA-positive patients had a histologically more advanced disease (P<0.01) and were more frequently cirrhotic compared with those who were negative (P<0.01). There was a positive correlation between AMA IgG3 titre and Mayo risk score (r=0.55, P=0.009, Spearman's correlation). CONCLUSIONS: Our findings suggest that AMA are not restricted to a specific IgG subclass. AMA of the IgG3 subclass are associated with a more severe disease course, possibly reflecting the peculiar ability of this isotype to engage mediators of damage.

Anti-mitochondrial antibody immunofluorescent titres correlate with the number and intensity of immunoblot-detected mitochondrial bands in patients with primary biliary cirrhosis.

BACKGROUND: Primary biliary cirrhosis (PBC)-specific anti-mitochondrial antibodies (AMA), routinely detected by indirect immunofluoresnce, immunofix various mitochondrial antigens by immunoblot (IB). We have investigated whether there is a relationship between IFL-determined AMA titres and the number, intensity or pattern of IB-bands. METHODS: By computer-assisted imaging technology, an IB analysis using human liver mitochondrial preparation was performed in 100 AMA positive PBC samples, subdivided in 5 groups each consisting of 20 cases with very high, high, intermediate, low or borderline IFL titres and in 19 AMA-negative cases. RESULTS: Reactivity to at least 1 mitochondrial band (range 1-12) was present in 114 (96%) cases. Reactivity to the major pyruvate dehydrogenase E2-subunit 74-kDa autoantigen positively correlated with AMA IFL titres but was absent in 25% IFL-positive cases. The intensity and number of IB-bands differed significantly among groups (p<0.001). IFL AMA titres positively correlated with the total number (r=0.8, p<0.001) and the intensity of the IB-bands (r=0.75, p<0.001). CONCLUSIONS: Our study indicates that IFL-determined AMA relate to the number and intensity of immunofixed bands. Reactivity to PDC-E2 does not correlate with IFL titres in a considerable proportion of patients suggesting that detection methods of AMA need to be based in the entire spectrum of the disease-specific mitochondrial antigens.

A study of molecular mimicry and immunological cross-reactivity between hepatitis B surface antigen and myelin mimics.

On the basis of the reported association between hepatitis B vaccination (HBvacc) and autoimmune demyelinating complications such as multiple sclerosis (MS), we have looked for aminoacid similarities between the small hepatitis B virus surface antigen (SHBsAg), and the MS-autoantigens myelin basic protein (MBP) and myelin oligodendrocyte glycoprotein (MOG) that could serve as targets of immunological cross-reactivity. Twenty-mer peptides spanning 4 SHBsAg/MOG and 1 SHBsAg/MBP mimicking pairs, were constructed and tested by ELISA as targets of cross-reactive responses. A total of 147 samples from 58 adults were collected before HBvacc (58/58), and post-HBvacc (48/58 before the second and 41/58 before the third boost). Eighty-seven sera from anti-SHBsAg antibody negative patients with various diseases were tested as pathological controls. Reactivity to at least one of the SHBsAg peptides was found in 8 (14%) pre-HBvacc subjects; amongst the remaining 50, reactivity to at least one of the SHBsAg peptides appeared in 47 (94%) post-HBvacc. Reactivity to at least one of the MOG mimics was present in 4 (8%) pre-HBvacc and in 30 (60%) post-HBvacc (p < 0.001). Overall 30/50 (60%) vaccinees had SHBsAg/MOG double reactivity on at least one occasion compared to none before-vaccination and in 2 (2%) of the pathological controls (p < 0.001 for both). SHBsAg/MOG double reactivity was cross-reactive as confirmed by inhibition studies. At 6 months post-vaccination, 3 of the 4 anti-MOG reactive cases before vaccination and 7 of the 24 (29%) of the anti-MOG reactive cases at 3 months post-vaccination had lost their reactivity to MOG5-24. There was no reactivity to the SHBsAg/MBP mimics. None of the vaccinees reported symptoms of demyelinating disorders. In view of the observed SHBsAg/MOG cross-reactivity, the vaccine's possible role as an immunomodulator of viral/self cross-reactivity must be further investigated.

Primary biliary cirrhosis is characterized by IgG3 antibodies cross-reactive with the major mitochondrial autoepitope and its Lactobacillus mimic.

The serological hallmark of primary biliary cirrhosis (PBC) is the presence of pyruvate dehydrogenase complex E2 subunit (PDC-E2) antimitochondrial antibodies (AMAs). Anti-PDC-E2 antibodies cross-react specifically with mycobacterial hsp65, and we have demonstrated that the motif SxGDL[ILV]AE shared by PDC-E2(212-226) and hsp's is a cross-reactive target. Having found that this same motif is present only in beta-galactosidase of Lactobacillus delbrueckii (BGAL LACDE), we hypothesized that this homology would also lead to cross-reactivity. The mimics were tested via ELISA for reactivity and competitive cross-reactivity using sera from 100 AMA-positive and 23 AMA-negative PBC patients and 190 controls. An Escherichia coli (ECOLI) PDC-E2 mimic that has been pathogenetically linked to PBC but lacks this motif has been also tested. Anti-BGAL(266-280) LACDE antibodies were restricted to AMA-positive patients (54 of 95, 57%) and belonged to immunoglobulin (Ig) G3. Of the 190 controls, 22 (12%; P < .001) had anti-BGAL(266-280) antibodies, mainly of the IgG4 subclass. ECOLI PDC-E2 reactivity was virtually absent. BGAL(266-280)/PDC-E2(212-226) reactivity of the IgG3 isotype was found in 52 (52%) AMA-positive PBC patients but in only 1 of the controls (P < .001). LACDE BGAL(266-280)/PDC-E2(212-226) reactivity was due to cross-reactivity as confirmed via competition ELISA. Antibody affinity for BGAL(266-280) was greater than for PDC-E2 mimics. Preincubation of a multireactive serum with BGAL(266-280) reduced the inhibition of enzymatic activity by 40%, while marginal effect (12%) or no effect (2%) was observed in human or ECOLI PDC-E2 mimics. In conclusion, IgG3 antibodies to BGAL LACDE cross-react with the major mitochondrial autoepitope and are characteristic of PBC.

Disease-specific cross-reactivity between mimicking peptides of heat shock protein of Mycobacterium gordonae and dominant epitope of E2 subunit of pyruvate dehydrogenase is common in Spanish but not British patients with primary biliary cirrhosis.

Previous studies on Spanish patients with Primary Biliary Cirrhosis (PBC) have shown extensive, disease-specific cross-reactivity between the 65-kDa heat shock protein (hsp65) of Mycobacterium gordonae and pyruvate dehydrogenase complex-E2 (PDC-E2), the major target of anti-mitochondrial antibody (AMA). Studies on a British population were unable to substantiate these findings. Having found that there is an excellent and almost unique match between the PDC-E2 autoepitope and a sequence in mycobacterial hsp65s, we tested the corresponding peptides by ELISA for cross-reactivity using sera from 90 PBC patients, 40 Spanish and 50 British, and 84 pathological controls. Reactivity to the MYCGO hsp65(90-104)/human PDC-E2(212-226)pair was present in 19 (47.5%) Spanish PBC patients and in 2 (4%) of the 50 British. Reactivity was not seen in any of the controls. Simultaneous reactivity to mimics was due to cross-reactivity as confirmed by inhibition studies. Three dimensional modelling predicts mycobacterial hsp65(90-104)to be exposed on the surface of the protein. The affinity of anti-hsp65(90-104)antibody was higher than that of anti-PDC-E2(212-226). Hsp65(90-104)is a target of disease-specific cross-reactivity to PDC-E2(212-226). The geographical confinement of this phenomenon is probably the result of complex genetic, environmental and immunological interaction.

Microbial mimics are major targets of crossreactivity with human pyruvate dehydrogenase in primary biliary cirrhosis.

BACKGROUND/AIMS: Previous studies on patients with primary biliary cirrhosis (PBC) have shown extensive cross-reactivity between the dominant B- and T-cell epitopes of human pyruvate dehydrogenase complex-E2 (PDC-E2), and microbial mimics. Such observations have suggested microbial infection as having a role in the induction of anti-mitochondrial antibodies, through a mechanism of molecular mimicry. However the biological significance of these cross-reactivities is questionable, because PDC-E2 is so highly conserved among various species. METHODS: Interrogating protein databases, ten non-PDC-E2 microbial sequences with high degree of similarity to PDC-E2(212-226) were found in Escherichia coli (6), Helicobacter pylori, Pseudomonas aeruginosa, Cytomegalovirus, and Haemophilus influenzae. We report on a study testing reactivity and competitive cross-reactivity against these respective peptides, and in some cases the parent protein, using sera from 55 patients with PBC, compared to reactivity of 190 pathological and 28 healthy controls. RESULTS: Cross-reactivity to E. coli mimics was commonly seen in PBC, and in a subset of pathological controls except where there was no evidence of urinary tract infection and correlated with anti-mitochondrial reactivity. CONCLUSIONS: E. coli/PDC-E2 cross-reactive immunity characterizes primary biliary cirrhosis; the large number of E. coli immunogenic mimics may account for the dominance of the major PDC-E2 autoepitope.

Antibodies to soluble liver antigen and alpha-enolase in patients with autoimmune hepatitis.

BACKGROUND: Antibodies to a cytosolic soluble liver antigen (SLA) are specifically detected in patients with autoimmune hepatitis (AIH). The target of anti-SLA has been identified as a ~50 kDa UGA serine tRNA-associated protein complex (tRNP(Ser)Sec), through the screening of cDNA libraries. A recent report questioned the identity of tRNP(Ser)Sec as the real SLA antigen. The latter study identified alpha-enolase as a major anti-SLA target, through proteomic analysis. METHODS: In an attempt to explain the observed discrepancy we have investigated reactivity of SLA positive sera against alpha-enolase and tRNP(Ser)Sec using rat and primate liver homogenate and the recombinant antigens. Thirty-three serum samples, 11 from SLA-positive patients and 22 from SLA negative controls were investigated. SLA antibodies were detected by an inhibition ELISA and confirmed by immunoblot using human liver homogenate. Autoantibody reactivity was further evaluated using preparations of primate and rat liver homogenates. Anti-alpha-enolase antibody reactivity has been tested by immunoblot using recombinant alpha-enolase. An affinity purified goat polyclonal anti-alpha-enolase IgG antibody was used as reference serum sample. Anti-tRNP(Ser)Sec antibody reactivity was detected by ELISA or dot blot using recombinant tRNP(Ser)Sec antigen. RESULTS AND DISCUSSION: The affinity purified IgG antibody directed to human alpha-enolase gave a band of approximately 48 kDa in both human and rat liver homogenates. A high titre anti-tRNP(Ser)Sec antibody serum gave a single band of ~50 kDa in both liver preparations. All but one anti-SLA antibody positive sera reacted with a ~50 kDa but none immunofixed a 48 kDa band. All anti-SLA antibody positive sera reacted strongly with the recombinant full length tRNP(Ser)Sec protein. None of the anti-SLA negative sera reacted with tRNP(Ser)Sec. Anti-SLA positive, and anti-SLA negative sera reacted equally against recombinant alpha-enolase by immunoblot. Pre-incubation of anti-SLA positive sera with tRNP(Ser)Sec completely abolished the 50 kDa band. The findings of the present study indicate that alpha-enolase and tRNP(Ser)Sec are both expressed in primate and rat liver and have a respective MW of 48 and 50 kDa. They also show that anti-tRNP(Ser)Sec - but not anti-alpha-enolase - correlates with anti-SLA antibody reactivity. CONCLUSION: Our findings indicate that tRNP(Ser)Sec is the most likely target of anti-SLA.