Pieter Meyer

Prof. Pieter Meyer

University of Pretoria
+1
orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2010 in Mediators of Inflammation
Verified
Journal Article
Open access
PDF file
Pieter MeyerPieter Meyer
Pieter Meyer
BHBridget Hodkinson
Bridget Hodkinson
MAMahmood Ally
Mahmood Ally
EMEustasius Musenge
Eustasius Musenge
AWAhmed A. Wadee
Ahmed A. Wadee
RARONALD ANDERSON
RONALD ANDERSON
Our objective was to analyse the relationship between circulating cytokines, autoantibodies, acute phase reactants, and disease activity in DMARDs-naïve rheumatoid arthritis (RA) patients (n=140). All cytokines were significantly higher in the RA cohort than in healthy controls. Moderate-to-strong positive intercorrelations were observed between Th1/Th2/macrophage/fibroblast-derived cytokines. RF correlated significantly with IL-1β, IL-2, IL-4, IL-10, IL-12, G-CSF, GM-CSF, IFN-γ, and TNF (P<.0001), and aCCP and aMCV with IL-1β, IL-2, IL-4, and IL-10 (P<.0002), while IL-6 correlated best with the acute phase reactants, CRP, and SAA (P<.0001). In patients with a DAS28 score of ≥5.1, IFN-γ, IL-1β, IL-1Ra, TNF, GM-CSF, and VEGF were significantly correlated (P<.04–.001) with high disease activity (HDA). Circulating cytokines in RA reflect a multifaceted increase in immune reactivity encompassing Th1 and Th2 cells, monocytes/macrophages, and synovial fibroblasts, underscored by strong correlations between these cytokines, as well as their relationships with RF, aCCP, and aMCV, with some cytokines showing promise as biomarkers of HDA.

8 March 2016 in Nicotine & Tobacco Research
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Journal Article
Closed access
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RARONALD ANDERSON
RONALD ANDERSON
Pieter MeyerPieter Meyer
Pieter Meyer
MAMahmood M. T. M. Ally
Mahmood M. T. M. Ally
MTMohammed Tikly
Mohammed Tikly
Smoking is now well recognized not only as a risk factor for rheumatoid arthritis (RA), but also as a determinant of disease activity, severity, response to therapy, and possibly mortality. Studies, mostly recent, which have provided significant insights into the molecular and cellular mechanisms which underpin the pathogenesis of smoking-related RA, as well as the possible involvement of other types of outdoor and indoor pollution form the basis of this review. Smoking initiates chronic inflammatory events in the lungs. These, in turn, promote the release of the enzymes, peptidylarginine deiminases 2 and 4 from smoke-activated, resident and infiltrating pulmonary phagocytes. Peptidylarginine deiminases mediate conversion of various endogenous proteins to putative citrullinated autoantigens. In genetically susceptible individuals, these autoantigens trigger the production of anti-citrullinated peptide, pathogenic autoantibodies, an event which precedes the development of RA. An increasing body of evidence has linked chronic inflammatory events in the lungs of smokers, to the production of anti-citrullinated peptide autoantibodies and development of RA. Creation of awareness of the associated risks, assessment of smoking status and implementation of compelling antismoking strategies must be included in the routine clinical management of patients presenting with suspected RA. Chronic inflammatory mechanisms operative in the lungs of smokers lead to the production of anti-citrullinated protein antibodies which, in turn, drive the development of RA. These mechanistic insights not only reinforce the association between smoking and risk for RA, but also the necessity to increase the level of awareness in those at highest risk.

1 January 2013 in Mediators of Inflammation
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Journal Article
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MAMahmood M. T. M. Ally
Mahmood M. T. M. Ally
BHBridget Hodkinson
Bridget Hodkinson
Pieter MeyerPieter Meyer
Pieter Meyer
EMEustasius Musenge
Eustasius Musenge
MTMohammed Tikly
Mohammed Tikly
RARONALD ANDERSON
RONALD ANDERSON
Matrix metalloproteinase-3 (MMP-3) is involved in the immunopathogenesis of rheumatoid arthritis (RA), but little is known about its relationship to genetic susceptibility and biomarkers of disease activity, especially acute phase reactants in early RA. MMP-3 was measured by ELISA in serum samples of 128 disease-modifying, drug-naïve patients and analysed in relation to shared epitope genotype, a range of circulating chemokines/cytokines, acute phase reactants, autoantibodies, cartilage oligomeric protein (COMP), and the simplified disease activity index (SDAI). MMP-3 was elevated >1.86 ng/ml in 56.25% of patients (P<0.0001), correlated with several biomarkers, notably IL-8, IL-6, IFNγ, VEGF and COMP (rvalues = 0.22–0.33,P<0.014–0.0001) and with CRP and SAA levels (r=0.40and 0.41, resp.,P<0.0000) and SDAI (r=0.29,P<0.0001), but not with erosions or nodulosis. However, the correlations of CRP and SAA with SDAI were stronger (respective values of 0.63 and 0.54,P<0.001for both). COMP correlated with smoking, RF, and MMP-3. MMP-3 is significantly associated with disease activity, inflammatory mediators and cartilage breakdown, making it a potential biomarker of disease severity, but seemingly less useful than CRP and SAA as a biomarker of disease activity in early RA.

31 October 2018 in CardioVascular Journal of Africa
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Journal Article
Closed access
Pieter MeyerPieter Meyer
Pieter Meyer
RARonald Anderson
Ronald Anderson
JKJames A Ker
James A Ker
MAMahmood Tm Ally
Mahmood Tm Ally
In developing countries, rheumatoid arthritis (RA) remains a seriously under-prioritised disease, particularly among the underprivileged, often resulting in presentation of patients late in the course of their disease, further complicated by limited therapeutic options and inconsistent follow up. The consequences are often severe with irreversible disability, increased frequency of co-morbidities, especially cardiovascular disease (CVD), and higher mortality rates, relative to developed countries. Despite addressing traditional cardiovascular risk factors, the impact of subclinical or 'residual' inflammation from uncontrolled RA needs to be considered. This narrative review explores the prevalence and pathogenesis of CVD in RA, including the impact of tobacco use. It discusses pitfalls in the risk assessment of CVD in patients with RA, and the effect of disease-modifying anti-rheumatic therapy on cardiovascular co-morbidity.

28 September 2007 in European Journal of Cancer Care
Verified
Journal Article
Closed access
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AUA. Uys
A. Uys
BRBernardo Rapoport
Bernardo Rapoport
HFH. Fickl
H. Fickl
Pieter MeyerPieter Meyer
Pieter Meyer
RARONALD ANDERSON
RONALD ANDERSON
The primary objective of the study was to compare the predictive potential of procalcitonin (PCT), C‐reactive protein (CRP), serum amyloid A (SAA), and interleukin (IL)‐1β, IL‐6, IL‐8, and IL‐10, with that of the Multinational Association of Supportive Care in Cancer (MASCC) risk‐index score in cancer patients on presentation with chemotherapy‐induced febrile neutropenia (FN). Seventy‐eight consecutive FN episodes in 63 patients were included, and MASCC scores, as well as concentrations of CRP, SAA, PCT, and IL‐1β, IL‐6, IL‐8 and IL‐10, and haematological parameters were determined on presentation, 72 h later and at outcome. Multivariate analysis of data revealed the MASCC score, but none of the laboratory parameters, to be an accurate, independent variable (P < 0.0001) for prediction of resolution with or without complications and death. Of the various laboratory parameters, PCT had the strongest association with the MASCC score (r = −0.51; P < 0.0001). In cancer patients who present with FN, the MASCC risk‐index score is a useful predictor of outcome, while measurement of PCT, CRP, SAA, or IL‐1β, IL‐6, IL‐8 and IL‐10, is of limited value.

30 January 2021 in Viruses
Verified
Journal Article
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EREsmari Rossouw
Esmari Rossouw
MBMarieke Brauer
Marieke Brauer
Pieter MeyerPieter Meyer
Pieter Meyer
NPNicolette du Plessis
Nicolette du Plessis
TATheunis Avenant
Theunis Avenant
JMJanet Mans
Janet Mans
Background: Viral gastroenteritis remains a major cause of hospitalisation in young children. This study aimed to determine the distribution and diversity of enteric viruses in children ≤5 years, hospitalised with gastroenteritis at Kalafong Provincial Tertiary Hospital, Pretoria, South Africa, between July 2016 and December 2017. Methods: Stool specimens (n = 205) were screened for norovirus GI and GII, rotavirus, sapovirus, astrovirus and adenovirus by multiplex RT-PCR. HIV exposure and FUT2 secretor status were evaluated. Secretor status was determined by FUT2 genotyping. Results: At least one gastroenteritis virus was detected in 47% (96/205) of children. Rotavirus predominated (46/205), followed by norovirus (32/205), adenovirus (15/205), sapovirus (9/205) and astrovirus (3/205). Norovirus genotypes GI.3, GII.2, GII.3, GII.4, GII.7, GII.12, GII.21, and rotavirus strains G1P[8], G2P[4], G2P[6], G3P[4], G3P[8], G8P[4], G8P[6], G9P[6], G9P[8] and sapovirus genotypes GI.1, GI.2, GII.1, GII.4, GII.8 were detected; norovirus GII.4[P31] and rotavirus G3P[4] predominated. Asymptomatic norovirus infection (GI.3, GI.7, GII.4, GII.6, GII.13) was detected in 22% of 46 six-week follow up stools. HIV exposure (30%) was not associated with more frequent or severe viral gastroenteritis hospitalisations compared to unexposed children. Rotavirus preferentially infected secretor children (p = 0.143) and norovirus infected 78% secretors and 22% non-secretors. Conclusion: Rotavirus was still the leading cause of gastroenteritis hospitalisations, but norovirus caused more severe symptoms.