Inhibitors to degraders: Changing paradigm in drug discovery

The chemical understanding of biological processes provides not only a deeper insight but also a solution to abnormal biological functioning. Protein degradation, a natural biological process for debris removal in the cell, has been studied for years. The recent finding that natural degradation pathways can be utilized for therapeutic purposes is a paradigm shift in the drug discovery approach. Methods such as Proteolysis Targeting Chimera (PROTAC), lysosomal targeting chimera, hydrophobic tagging, AUtophagy TArgeting Chimera, AUTOphagy TArgeting Chimera and several other variants of these methods have made a considerable impact on the way of drug design. Few selected examples testify that a huge wave of change is on the way. The drug design based on the targeted protein degradation is a powerful tool in our arsenal. More molecules will be invented that will uncover the hidden secrets of biological functioning and provide enduring solutions to several unmet medical needs.

Correction: Bispidine-Amino Acid Conjugates Act as a Novel Scaffold for the Design of Antivirals That Block Japanese Encephalitis Virus Replication

[This corrects the article DOI: 10.1371/journal.pntd.0002005.].

Highly Efficient Intramolecular Excimer Formation in a Disulfide-Linked Dipyrenyl Compound: Proton Recognition and Fluidity Assessment

Intramolecular excimer formation has been utilized extensively in chemical sciences, especially to probe solvation within complex media as well as to assess physicochemical properties of the solubilizing milieu. Pyrene has been employed extensively as a fluorescence probe for this purpose due to its favorable multidimensional fluorescence properties. Termini-capped dipyrenyl scaffolds possessing various functionalities comprise the majority of such compounds. A new both end-tagged dipyrenyl compound DTP is designed and synthesized, which exhibits significantly high intramolecular excimer formation efficiency in polar solvents. The presence of a -NH-(CO)- and/or -S-S- functionality on the chain linking the two pyrenyl groups facilitates intramolecular excimer formation. Excited-state emission intensity decay reveals that the excimer formation exclusively takes place in the excited state with only one excimer conformation. The rate constant of excimer formation is found to be higher for DTP as compared to a similar compound with an alkyl backbone. The dependence of the excimer formation on the solvent (protic versus aprotic) as well as on temperature reveals further insights into the excimer formation process. The excimer formation by DTP is found to be highly sensitive to the presence of H+: the relative excimer formation efficiency decreases drastically in the presence of a small amount of H+ (∼10-5 M). Further, the recognition of protons by DTP via intramolecular excimer formation is also observed to be highly selective in nature. Based on the observation that both the excimer formation efficiency and kinetics depend on the viscosity of the solubilizing milieu, fluidity assessment of the (dimethyl sulfoxide + acetonitrile) mixture was carried out using DTP. Further, DTP is found to be an effective probe for the assessment of the amount of water in the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide as well as in a deep eutectic solvent composed of choline chloride and urea in a 1:2 mol ratio. Highly efficient and rapid intramolecular excimer formation not only establishes DTP as a useful and versatile probe but also offers strategic pathways for designing effective excimer-forming compounds.

Bispidine as a Versatile Scaffold: From Topological Hosts to Transmembrane Transporters

The development of designer topological structures is a synthetically challenging endeavor. We present herein bispidine as a platform for the design of molecules with various topologies and functions. The bispidine-based acyclic molecule, which shows intriguing S-shape topology, is discussed. Single-crystal X-ray diffraction studies revealed that this molecule exists in the solid state as two conformational enantiomers. In addition, bispidine-based designer macrocycles were synthesized and investigated for ionophoric properties. Patch clamp experiments revealed that these macrocycles transport both anions and cations non-specifically with at least tenfold higher chloride conductance over the cations under the given experimental conditions. Ultramicroscopy and single-crystal X-ray crystallographic studies indicated that the self-assembling macrocycle forms a tubular assembly. Our design highlights the use of unconventional dihydrogen interactions in nanotube fabrication.

Bispidine as a promising scaffold for designing molecular machines

The development of artificial molecular machines is a challenging endeavor. Herein, we have synthesized a series of bispidine diamides D1-D6 that exhibit rotation reminiscent of a motor motion. Dynamic NMR, X-ray diffraction, quantum mechanical calculations, and molecular dynamics simulations provided insights into their rotational dynamics. All the diamides D1-D6 exhibited mutually independent rotation around the two bispidine arms. However, the rate of rotation and the presence or absence of directionality in amide bond rotation were found to depend on the solvent, temperature, and nature of substitution on the amide carbonyl. These engineered systems may aid in the development of biologically relevant synthetic molecular motors. Studies on homochiral and heterochiral bispidine-peptides revealed that the direction of rotation can be controlled by chirality and the nature of the amino acid.

Occurrence and outcome of COVID-19 in AIRD patients on concomitant treatment with Tofacitinib- results from KRA COVID COHORT (KRACC) subset

INTRODUCTION

We assessed the risk factors and outcome of COVID-19 in patients with autoimmune rheumatic diseases(AIRD) who contracted infection while on background treatment with tofacitinib.

METHODS

This is a non-interventional, cross-sectional, questionnaire based telephonic study which included consecutive AIRD patients on tofacitinib co-treatment. Data related to the AIRD subset, disease modifying anti rheumatic drugs(DMARDs) including glucocorticoids and comorbidities, was collected from 7 rheumatology centers across Karnataka during the second wave of COVID-19 pandemic. The information about COVID-19 occurrence and COVID-19 vaccination was recorded.

RESULTS

During the study period (Jun-July 2021), 335 AIRD patients (80.6% female) on treatment with tofacitinib were included. The mean duration of tofacitinib use was 3.4+/-3.1months. Thirty-six(10.75%) patients developed COVID-19. Diabetes mellitus (p = 0.04 (OR 2.60 (1.13-5.99)) was identified as a risk factor for COVID-19 in our cohort. Almost half of our cohort was COVID-19 vaccinated with at least one dose, with resultant decline in incidence of COVID-19(OR 0.15 (0.06-0.39) among the vaccinated. Recovery amongst COVID-19 infection group was 91.2%.

CONCLUSIONS

The subset of AIRD patients who were on treatment with tofacitinib were found to have a higher rate of COVID-19 infection as compared to our KRACC cohort. Pre-existing comorbidity of diabetes mellitus was the significant risk factor in our cohort. This subset of the KRACC cohort shows RA patients had a lesser infection and PsA patients had a higher infection.

Expanded triazolophanes: a topological analysis of vesicular assembly

Triazolophanes with larger ring sizes such as 40- and 42- were designed and synthesized. Ultramicroscopic studies on a variety of expanded triazolophanes and larger acyclic systems revealed vesicular self-assembly. The role of molecular topology on vesicular assembly was systematically investigated by studying a series of molecules with increasing curvature.

Pseudopeptosomes: non-lipidated vesicular assemblies from bispidine-appended pseudopeptides

We report a novel molecular topology-based approach for creating reproducible vesicular assemblies in different solvent environments (including aqueous) using specifically designed pseudopeptides. Deviating from the classical "polar head group and hydrophobic tail" model of amphiphiles, we showed (reversible) self-assembly of synthesized pseudopeptides into vesicles. Naming these new type/class of vesicles "pseudopetosomes", we characterized them by high-resolution microscopy (scanning electron, transmission electron, atomic force, epifluorescence and confocal) along with dynamic light scattering. While accounting for hydropathy index of the constituent amino acids (side chains) of pseudopeptides, we probed molecular interactions, resulting in assembly of pseudopeptosomes by spectroscopy (fourier-transform infrared and fluorescence). Molecular characterization by X-ray crystallography and circular dichroism revealed "tryptophan (Trp)-Zip" arrangements and/or hydrogen-bonded one-dimensional assembly depending on specific pseudopeptides and solvent environments. Our data indicated that pseudopeptosomes are formed in solutions by self-assembly of bispidine pseudopeptides (of Trp, leucine and alanine amino-acid constituents) into sheets that transform into vesicular structures. Thus, we showed that assembly of pseudopeptosomes utilizes the full spectrum of all four weak interactions essential in biological systems. Our findings have direct implications in chemical and synthetic biology, but may also provide a new avenue of investigations on origins of life via pseudopeptosome-like assemblies. We also showed that these designer peptides can act as carriers for cellular transport.

Fluorescence by self-assembly: autofluorescent peptide vesicles and fibers

A series of oxidized cysteinyl peptides ([P-Cys-X-OMe]₂; P = Boc or H; X = Trp or Glu) showed vesicular and fibrillar assemblies. The anatomy of the self-assembled vesicles from the water-soluble cystine peptide [Cys-Trp-OMe]₂ (1a) has been investigated by using various fluorescent probes such as ammonium 8-anilinonaphthalene-1-sulfonate, Nile Red and pyrene. The morphological characterization was carried out by fluorescence lifetime imaging microscopy (FLIM) and super resolution-structured illumination microscopy (SR-SIM) utilizing the autofluorescence of the vesicles stemming from the self-assembly. The self-assembled structures are also observed in solution as evident from the quantitative phase images obtained using a dual-mode digital holographic microscope (DHM) system. Present investigations show that the self-assembly is enthalpy- and entropy-driven in the aqueous medium. Based on the CD spectral studies, we proposed that 1a organizes into vesicles through the sequestration of indole units. We observed that the solutions of dipeptides 1a-b exhibit autofluorescence in the blue region upon excitation at a wavelength >350 nm. Detailed spectroscopic studies on the peptides lacking tryptophan 2a-b unequivocally showed that the autofluorescence stems exclusively from peptide aggregation. Our experimental results with appropriate controls revealed that the clustering of carbonyl chromophores is central to autofluorescence. Autofluorescence was also used to probe the vesicle formation without using any external fluorescent probe. To the best of our knowledge, this is the first report on autofluorescent vesicles formed by the spontaneous association of dipeptides. We also found that the vesicles formed by 1a can act as a host for guests like C₆₀. The biocompatibility and biodegradability of these peptides along with the autofluorescent nature and guest binding ability of peptide-based vesicles offer numerous applications in the biomedical area.

Risk factors associated with COVID-19 in systemic lupus erythematosus: Results from a longitudinal prospective cohort

INTRODUCTION

Patients with SLE (systemic lupus erythematosus) have a higher risk of infection due to dysregulated immune system as well as long-term use of immunosuppressants (IS). This could influence the risk of COVID-19 and its outcome.

METHODS

We conducted a longitudinal prospective study across 15 rheumatology centres during the first wave of the pandemic to understand the risk factors contributing to COVID-19 in SLE patients. During the 6 months follow-up, those who tested positive for COVID-19, their clinical course and outcome information were recorded.

RESULTS

Through the study period (April-December 2020), 36/1379 lupus patients (2.9%) developed COVID-19. On analysing the COVID-19 positive versus negative cohort during the study period, male gender (adjusted RR 3.72, 95% C.I. 1.85,7.51) and diabetes (adjusted RR 2.94, 95% C.I. 1.28, 6.79) emerged as the strongest risk factors for COVID-19, in the adjusted analysis. There was no significant influence of organ involvement, hydroxychloroquine, glucocorticoid dosage (prednisolone< 7.5 mg or ≥ 7.5 mg/day) or IS on the risk of COVID-19. There was only one death (1/36) among the lupus patients due to COVID-19.

CONCLUSION

Traditional risk factors rather than lupus disease process or IS influenced the risk of COVID-19 in our cohort.

Liquid crystal droplet design by using pseudopeptidic bottlebrush polymer additives

Liquid crystal (LC) droplets are promising candidates for sensing applications due to their high sensitivity to surface anchoring changes, resulting in readily detectable optical effects. Herein, we have designed and synthesized amino acid-based bottlebrush polymers and investigated their impact on LC director configurations in the droplets. The pseudopeptidic bottlebrush polymers with an aromatic (phenyl) and aliphatic appendages are synthesized using ring-opening metathesis polymerization (ROMP). Polymer dispersed liquid crystal (PDLC) samples are prepared by employing pseudopeptidic bottlebrush polymers and 4-cyano-4'-pentylbiphenyl (5CB) LC via solvent-induced phase separation (SIPS) technique. Due to π-π stacking, the phenyl group favours radial configuration, whereas the repulsion between 5CB and aliphatic groups induces molecular alignment leading to bipolar droplet arrangement. The impact of various pendant groups attached to the polymer on the prepared PDLC sample's surface characteristics and free energy components is illustrated. The sensing capability of 5CB dispersed in pseudopeptidic bottlebrush polymers for various pH solutions is investigated using polarizing optical microscopy (POM). The PDLC samples are moderately permeable to water and sensitive to different pH solutions. The results demonstrate a simplified and straightforward approach for preparing LC-based biosensors and chemical sensors.

Designer Peptide-PVDF Composite Films for High Performance Energy Harvesting

Polymers and peptides have recently been considered as promising materials for piezoelectric energy harvesting because of their biocompatibility and enormous design possibility. However, achieving significant output voltages while meeting environmental safety requirements, low-cost and easy fabrication remains a major challenge. Herein, we have fabricated a lipidated pseudopeptide incorporated poly(vinylidene fluoride) (PVDF) composite films. Adding lipidated pseudopeptide (BLHA) increases the electroactive phase content, reaching the maximum for the 2 wt% composite film. The composite film containing 2 wt% BLHA manifests the highest dielectric constant and remnant polarization (P_r ), among others. A piezoelectric energy harvesting device fabricated with this film generates open-circuit output voltages up to 23 V, five times amplified output compared to pure PVDF. To the best of our knowledge, this material is superior among the peptide-based piezoelectric energy harvesters reported in the literature. The device is flexible, durable, low-cost, and sensitive to high and low pressures. It can power up multiple LCD panels when pressed with a finger. The non-covalent interaction between BLHA and PVDF is the reason behind the composites' improved piezoelectric response. Density functional theory (DFT) calculations also support this notion. This article is protected by copyright. All rights reserved.

Designer peptides as versatile building blocks for functional materials

Peptides and pseudopeptides show distinct self-assembled nanostructures such as fibers, nanotubes, vesicles, micelles, toroids, helices and rods. The formation of such molecular communities through the collective behavior of molecules is not fully understood at a molecular level. All these self-assembled nanostructured materials have a wide range of applications such as drug delivery, gene delivery, biosensing, bioimaging, catalysis, tissue engineering, nano-electronics and sensing. Self-assembly is one of the most efficient and a simple strategy to generate complex functional materials. Owing to its significance, the last few decades witnessed a remarkable advancement in the field of self-assembling peptides with a plethora of new designer synthetic systems being discovered. These systems range from amphiphilic, cyclic, linear and polymeric peptides. This article presents only selected examples of such self-assembling peptides and pseudopeptides.

Molecular Insights into the Inhibition of Dialysis-Related β2m Amyloidosis Orchestrated by a Bispidine Peptidomimetic Analogue

Dialysis-related amyloidosis (DRA) is considered an inescapable consequence of renal failure. Upon prolonged hemodialysis, it involves accumulation of toxic β2-microglobulin (β2m) amyloids in bones and joints. Current treatment methods are plagued with high cost, low specificity, and low capacity. Through our in vitro and in cellulo studies, we introduce a peptidomimetic-based approach to help develop future therapeutics against DRA. Our study reports the ability of a nontoxic, core-modified, bispidine peptidomimetic analogue "B(LVI)₂" to inhibit acid-induced amyloid fibrillation of β2m (Hβ2m). Using thioflavin-T, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and transmission electron microscopy analysis, we demonstrate that B(LVI)₂ delays aggregation lag time of Hβ2m amyloid fibrillation and reduces the yield of Hβ2m amyloid fibrils in a dose-dependent manner. Our findings suggest a B(LVI)₂-orchestrated alteration in the route of Hβ2m amyloid fibrillation resulting in the formation of noncytotoxic, morphologically distinct amyloid-like species. Circular dichroism data show gradual sequestration of Hβ2m species in a soluble nonamyloidogenic noncytotoxic conformation in the presence of B(LVI)₂. Dynamic light scattering measurements indicate incompetence of Hβ2m species in the presence of B(LVI)₂ to undergo amyloid-competent intermolecular associations. Overall, our study reports the antifibrillation property of a novel peptidomimetic with the potential to bring a paradigm shift in therapeutic approaches against DRA.

Ratiometric Recognition of Protons by a Multiple Tagged Designer Fluorescent Chemosensor

Molecular architecture with different fluorophoric units can offer improved and effective recognition of biologically important analytes. We present here a new strategy for the design of ratiometric chemosensors that operate by photoinduced electron transfer (PET). This ratiometric sensor endowed with tryptophan and anthracene exhibits high sensitivity, excellent selectivity and remarkable reversibility towards recognition of H⁺ in methanol. This "Turn-On" type behaviour is crafted into the molecule by incorporation of bispidine entity. Effective quenching of the fluorescence of the anthracene by the adjacent amine groups of the bispidine results in negligible fluorescence from the anthracene group leading to highly sensitive recognition of protons by the compound as H⁺ protonate the amine functionalities giving rise to the emergence of the fluorescence from the anthracene group. This, combined with the reduction in the fluorescence from the Trp group by H⁺, results in highly sensitive ratiometric nature of the response especially at low [H⁺].

A prospective longitudinal study evaluating the influence of immunosuppressives and other factors on COVID-19 in autoimmune rheumatic diseases

Background

We conducted this study to identify the influence of prolonged use of hydroxychloroquine (HCQ), glucocorticoids and other immunosuppressants (IS) on occurrence and outcome of COVID-19 in patients with autoimmune rheumatic diseases (AIRDs).

Methods

This was a prospective, multicenter, non-interventional longitudinal study across 15 specialist rheumatology centers. Consecutive AIRD patients on treatment with immunosuppressants were recruited and followed up longitudinally to assess parameters contributing to development of COVID-19 and its outcome.

Results

COVID-19 occurred in 314 (3.45%) of 9212 AIRD patients during a median follow up of 177 (IQR 129, 219) days. Long term HCQ use had no major impact on the occurrence or the outcome of COVID-19. Glucocorticoids in moderate dose (7.5–20 mg/day) conferred higher risk (RR = 1.72) of infection. Among the IS, Mycophenolate mofetil (MMF), Cyclophosphamide (CYC) and Rituximab (RTX) use was higher in patients with COVID 19. However, the conventional risk factors such as male sex (RR = 1.51), coexistent diabetes mellitus (RR = 1.64), pre-existing lung disease (RR = 2.01) and smoking (RR = 3.32) were the major contributing risk factors for COVID-19. Thirteen patients (4.14%) died, the strongest risk factor being pre-existing lung disease (RR = 6.36, p = 0.01). Incidence (17.5 vs 5.3 per 1 lakh (Karnataka) and 25.3 vs 7.9 per 1 lakh (Kerala)) and case fatality (4.1% vs 1.3% (Karnataka) and 4.3% vs 0.4% (Kerala)) rate of COVID-19 was significantly higher (p < 0.001) compared to the general population of the corresponding geographic region.

Conclusions

Immunosuppressants have a differential impact on the risk of COVID-19 occurrence in AIRD patients. Older age, males, smokers, hypertensive, diabetic and underlying lung disease contributed to higher risk. The incidence rate and the case fatality rate in AIRD patients is much higher than that in the general population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41927-022-00264-0.

Bispidine as a β-strand nucleator: from a β-arch to self-assembled cages and vesicles

The development of synthetic scaffolds that nucleate well-folded secondary structures is highly challenging. Herein, we designed and synthesized a series of core-modified peptides (F1, F2, F3, and F4) that fold into β-strand structures. These bispidine-scaffolded peptides were studied by CD, IR, NMR, single crystal XRD, and Molecular Dynamics (MD) simulations to investigate their conformational preferences. Solid-state and solution studies revealed that bispidine is a versatile scaffold that could be placed either at the terminal or at the middle of the peptide strand for nucleating the β-strand structure. Scaffolds that nucleate an isolated β-strand conformation are rare. Bispidine placed at the C-terminus of the peptide chain could nucleate a β-strand conformation, while bispidine placed at the middle resulted in a β-arch conformation. This nucleation activity stems from the ability to restrict the psi torsion angle (ψ) through intramolecular C5 hydrogen bonding between the equatorial hydrogen(s) of bispidine and the carbonyl oxygen(s) of the amino acid close to the scaffold. Furthermore, the bispidine peptidomimetic with a super secondary structure, namely β-arch, assembled into single-hole submicron cages and spherical vesicles as evident from microscopic studies. The design logic defined here will be a significant strategy for the development of β-strand mimetics and super secondary structures.

Interaction of borohydride stabilized silver nanoparticles with sulfur-containing organophosphates

Understanding the interactions between nanoparticles and organophosphates is the key to developing cost-effective colorimetric pesticide detection. We have studied the interaction between three different organophosphates containing the P[double bond, length as m-dash]S group and borohydride stabilized silver nanoparticles. Three different organophosphates, namely phorate, chlorpyrifos, and malathion, have been used. The colorimetric changes are corroborated with UV-visible absorption studies along with the change in particle size and zeta potential. This effect persists in the presence of NaCl solution also. The chlorpyrifos and malathion do not show significant interactions with uncapped nanoparticles over time, while phorate undergoes degradation due to the scission of the S-CH2 linkage. A reaction mechanism, wherein a silver and sulfur (Ag→S) complex is formed, which is in agreement with Raman spectroscopic studies is proposed. The orientations of phorate near Ag nanoparticles are discussed from the adsorption energy calculation using density functional theory.

Chemical Biology of Sortase A Inhibition: A Gateway to Anti-infective Therapeutic Agents

Staphylococcus aureus is the leading cause of hospital-acquired infections. The enzyme sortase A, present on the cell surface of S. aureus, plays a key role in bacterial virulence without affecting the bacterial viability. Inhibition of sortase A activity offers a powerful but clinically less explored therapeutic strategy, as it offers the possibility of not inducing any selective pressure on the bacteria to evolve drug-resistant strains. In this Perspective, we offer a chemical space narrative for the design of sortase A inhibitors, as delineated into three broad domains: peptidomimetics, natural products, and synthetic small molecules. This provides immense opportunities for medicinal chemists to alleviate the ever-growing crisis of antibiotic resistance.

Tailoring of Peptide Vesicles: A Bottom-Up Chemical Approach

Spherical ordering from small molecules is a subject of intense interest to chemists. The inherent capability of amphiphiles to assemble spontaneously is the unique feature of the evolutionary process of life. Self-assembly is prevalent in biology and has attracted the interest of scientists across several disciplines. This is because scientists have realized that nature has extensively used this inherent organizational power contained in the molecules. Judicious use of the self-assembly principle is the cornerstone of nature's exotic assemblies. These exotic assemblies lead to unimaginable functions in biology that might not have been predicted from the monomer building blocks alone. Recently, a number of chemical systems that self-assemble in aqueous or organic solvents to form vesicles were reported. This account provides advances made from our laboratory toward designing and understanding the mechanism of formation of spherical vesicular assembly. A bottom-up approach for the de novo design of vesicles using nonlipidated molecular architecture will be a paradigm shift in vesicular research. Vesicles act as a protocell model for studying the origin and evolution of cellular life. They could also act as excellent model systems for studying the fusion of cells and membrane transport. Self-assembled vesicles have enormous potential for several applications such as drug and biomolecule delivery to cells and in materials science. These aspects along with the dynamic nature of vesicular assembly have attracted researchers to the study of spherical assemblies. The common belief was that the molecules that form vesicles must have one polar head and two hydrophobic tails. All attempts to synthesize vesicles are by mimicking nature's strategy, which mainly involves the self-assembly of lipid amphiphiles through a bilayer-like arrangement. Pseudopeptide-based molecules with the ability to form vesicles have changed this long-standing notion. In addition to chemical and medical applications, these peptide vesicles could act as models for protocells, membrane fusion, and the study of the vesiculation mechanism. This Account highlights the progress made toward a heuristic approach to the de novo design of vesicles using pseudopeptides as building blocks.A large number of diverse classes of pseudopeptides showed vesicular assembly. Various acyclic and cyclic molecules were designed and synthesized that showed spherical vesicular assembly. Cystine-based macrocyclic peptides showed drug encapsulation and release. Polymersomes with unusual topology, self-assembling tripodal ligands, and molecules containing amino acids such as lysine, leucine, cystine, and serine were synthesized. The incorporation of a wide variety of amino acids in the vesicle-forming peptides could enhance their scope and applications. The mechanism of vesiculation was also investigated using these designer molecules.

Is butyrate a natural alternative to dexamethasone in the management of CoVID-19?

Coronavirus disease 2019 (CoVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 has affected more than 100 million lives. Severe CoVID-19 infection may lead to acute respiratory distress syndrome and death of the patient, and is associated with hyperinflammation and cytokine storm. The broad spectrum immunosuppressant corticosteroid, dexamethasone, is being used to manage the cytokine storm and hyperinflammation in CoVID-19 patients. However, the extensive use of corticosteroids leads to serious adverse events and disruption of the gut-lung axis. Various micronutrients and probiotic supplementations are known to aid in the reduction of hyperinflammation and restoration of gut microbiota. The attenuation of the deleterious immune response and hyperinflammation could be mediated by short chain fatty acids produced by the gut microbiota. Butyric acid, the most extensively studied short chain fatty acid, is known for its anti-inflammatory properties. Additionally, butyric acid has been shown to ameliorate hyperinflammation and reduce oxidative stress in various pathologies, including respiratory viral infections. In this review, the potential anti-inflammatory effects of butyric acid that aid in cytokine storm depletion, and its usefulness in effective management of critical illness related to CoVID-19 have been discussed.

Supersensitive Detection of Anions in Pure Organic and Aqueous Media by Amino Acid Conjugated Ellman's Reagent

The last few decades witnessed a remarkable advancement in the field of molecular anion receptors. A variety of anion binding motifs have been discovered, and large number of designer molecular anion receptors with high selectivity are being reported. However, anion detection in an aqueous medium is still a formidable challenge as evident from only a miniscule of synthetic systems available in the literature. We, herein, report 5,5'-dithio-bis(2-nitrobenzoic acid) (Ellman's reagent) appended with amino acids as supersensitive anion sensors that can detect F^- and H₂PO₄^- ions in both aqueous as well as organic media. Interestingly, the sensors showed a dual response to anions, viz., chromogenic response in organic medium and electrochemical response in aqueous solutions. Various spectroscopic techniques such as UV-vis and ¹H NMR are used to investigate the binding studies in acetonitrile, whereas electrochemical methods such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV) are employed to explore the anion binding in water. The host-guest complex stoichiometry and binding constants are calculated using the BindFit software. The geometry of host-guest complex has been optimized by the density functional theory (DFT) method. These molecules are versatile sensors since these function in both water and acetonitrile with extremely low limit of detection (LOD) up to 0.07 fM and limit of quantification (LOQ) up to 0.23 fM. To our knowledge, the present system is the first example of a sensor that can detect the lowest concentration of anions in water quantitatively. The minimalistic design strategy presented here opens up the innumerable possibilities for designing dual anion sensors in a one fell swoop.

Maternal and fetal outcomes of lupus pregnancies: A collective effort by Karnataka Rheumatologists

INTRODUCTION

Identifying factors predicting adverse pregnancy outcomes involving systemic lupus erythematosus (SLE) is a research priority. The aims of this study were to investigate (a) the maternal and fetal outcomes of pregnant lupus patients and the factors associated with adverse pregnancy outcomes, and (b) the effect of pregnancy on lupus disease activity of these patients.

METHODS

This was an ambi-directional study collecting information from five multi-specialist referral centres across the state of Karnataka, India over 5 years (2013-2018). Clinical details of pregnancies and outcomes that were temporally associated with lupus disease were recorded using a structured pro forma. The Safety of Estrogen in SLE National Assessment-SLE Disease Activity Index (SELENA-SLEDAI) was used to assess lupus activity during the 6 months prior to pregnancy and the intra- and post-partum periods. Modifications suggested in the SLE Pregnancy Disease Activity Index were considered while scoring.

RESULTS

A total of 121 pregnancies in 80 SLE patients with a mean age of 27.1 (±4.5) years and with a mean disease duration of 4.6 (±4.1) years were reviewed. Largely patients were in clinical remission (109/121; 90.1%). Antiphospholipid antibody positivity was seen in 45/121 (37.2%) patients. A history of lupus nephritis was noted in 29/121 (24%) patients. Maternal complications (32%) were mainly due to hypertensive disorders of pregnancy (HDP; 19/121; 15.7%). Adverse fetal outcomes (58%) were mainly in the form of spontaneous first-trimester abortions (21/121; 16%), stillbirth (14/121; 11.6%) and prematurity (24/121; 20%). HDP is strongly associated with stillbirth and prematurity and is independent of active lupus. Disease activity was associated with a three-fold increased risk of adverse fetal outcome in univariate analysis. The risk of major flare during pregnancy is low (4.1%) when conception occurs during stable disease. Hydroxychloroquine (HCQ) use was associated with reduced risk of flare (p = 0.001) in patients in remission at the time of conception.

CONCLUSIONS

The risk of major flare during pregnancy is low when conception happens during stable disease. HCQ use was associated with reduced risk of flare in patients in remission at the time of conception. HDP was strongly associated with stillbirth and prematurity and are independent of active lupus in our cohort.

AB0785 REAL LIFE EXPERIENCE OF METHOTREXATE BASED DUAL COMBINATION DMARDS IN PSORIATIC ARTHRITIS- RESULTS FROM KARNATAKA PSORIATIC ARTHRITIS COHORT (KPsAC)

Background:

Biologics have been the focus of recent treatment guidelines and ‘Treat to Target’ strategies for both psoriasis (PsO) & psoriatic Arthritis (PsA). However, in day-today practice, combination DMARDs anchored around methotrexate are mainstay in majority of patients.

Objectives:

To describe experience and effectiveness of Methotrexate in combination with conventional DMARDs in Karnataka Psoriatic Arthritis Cohort.

Methods:

Treatment information was extracted from KPsAC (n=549) which is a cross sectional, non-interventional study conducted across 17 rheumatology practicing centres in Karnataka, India using a structured proforma. This study was approved by respective Ethical committee. Information on efficacy was extracted for various csDMARDs in combination with methotrexate. Standard disease activity outcome measures were used for assessing the response to therapy (DAPSA, PASI, HAQ, MDA5). All participating rheumatologists underwent training to calculate PASI and other outcome scores.

Results:

Nearly half of the patients in our cohort were on methotrexate (44%) monotherapy. Proportion of patients who received combination csDMARD anchored on methotrexate were 29%. The choice of add on csDMARD was as per clinician discretion or subject preference. Patients were divided in to three groups based on treatments they were receiving at the time of study: Methotrexate (Mtx)+Leflunomide (Lef), Mtx+Sulfasalazine (SSz) and Mtx+Apremilast(Apr). Their characteristics along with outcome measures are depicted in table 1. In Mtx+Apr group: remission or low disease activity was present in 42%, HAQ score of <0.5 was seen in 82%, and only one patient had a PASI of > 10. PASI was significantly lower in the Mtx+Apr group compared to Mtx+Lef group (p<0.009) and Mtx +Ssz group (p < 0.020)

Conclusion:

Apremilast is an orally administered, small molecule inhibitor of phosphodiesterase 4 (PDE4)**. In this observational study, 3 groups of methotrexate plus csDMARD- leflunomide, sulphasalazine and apremilast fared similarly for articular domain of PsA. However, in cutaneous domain, PASI was significantly lower in apremilast + methotrexate group. To our knowledge, this is the first real life report of the use of combination DMARDs in unselected PsA patients demonstrating effectiveness of apremilast in cutaneous domain. Methotrexate remains anchor DMARD for treatment of PsA in 2/3rdof PsA patients. Addition of apremilast to methotrexate inadequate responders appears to be beneficial in PsA with persistent cutaneous disease. However, being an observational study, this needs to be confirmed in controlled clinical trials.

References:

**Apremilast: A Review in Psoriasis and Psoriatic Arthritis, Drugs March 2017, Volume 77, Issue 4.

Table.

Characteristics and comparison of combination csDMARDs

MTX+SSZ(N=39)MTX+LEF (n=77)MTX+APR(N=45)Median Age (years)373935Median disease duration (months)96101112Enthesitis (Ever)6(15%)21(27%)4(8%)Dactylitis (Ever)9((23%)28(36%)12 (26%)DAPSA < 46(15%)9(11%)10(22%) 4-1414(36%)25(32%)13(29%) 14-287(18%)24(31%)11(24%)PASI >107(18%) #14(18%) *1(2%) *#HAQ < 0.530(77%)60(78%)37(82%)MDA 5 achieved16(41%)25(32%)19(42%)

*P value < 0.009 #P value <0.02

Disclosure of Interests:

None declared

AB0790 CLINICAL PROFILING OF PSORIATIC ARTHRITIS (PsA): AN OBSERVATIONAL STUDY FROM A SOUTH INDIAN PSORIATIC ARTHRITIS COHORT

Background:

Clinical patterns and disease burden of PsA varies in different parts of the world. Demographic studies from Indian subcontinent are sparse

Objectives:

To study the cutaneous, articular profile of PsA and describe their disease activity, disability and co-morbidities (CMs)

Methods:

This is a multicenter, cross-sectional, non-interventional study from Karnataka, India. All consecutive PsA patients defined by CASPAR or expert diagnosis were evaluated over 8 months from 17 Rheumatology centers across Karnataka using standard parameters such as PASI, DAPSA, Indian version of HAQ-DI1, psoriatic co-morbidity index2(Cidx) and MDA 5. Patient consent and EC obtained

Results:

549 PsA patients were evaluated and their disease characteristics are shown in Table 1 & 2. PsA preceded psoriasis in in 81 (14.7%).

Table 1.

Patient characteristics (n=549)

DEMOGRAPHICSPsACommonest age group of PsA (yrs)31-40PsA SubclassificationM:F6:5Symmetric polyarthritis216(40.7%)Type 1 PsoriasisType 2 Psoriasis279(55.8%)221(44.2%)Mean duration (yrs)Asymmetric oligoarthritis202(38.1%)Psoriasis8.8(±7.8)DIP predominant88(16.6%)PsA5.2(±6.3)Arthritis mutilans16(4.2%)PsA preceded psoriasis81(14.7%)Dactylitis182(33.9%)Family h/oPsoriasis107(19.7%)Enthesitis109(20.3%)PsA33(6%)Mean TJC686.3(±8.9)AS11(2%)Mean SJC683.5(±5.2)Uveitis5(0.9%)Type of PsoriasisPlaque253(59.9%)IBD3(0.5%)Erythrodermic 31(7.3%)

Type I & II psoriasis did not differ in PASI, DAPSA, HAQ-DI or having a family h/o psoriasis. Type II psoriasis had higher Cidx than type I (p=0.0001). Pt pain VAS, DAPSA, PhyGA, PtGA & SJC significantly correlated with higher HAQ-DI (p<0.0001). TJC, ESR, CRP & PASI had minor correlation with HAQ-DI. Females had higher HAQ-DI compared to males (p=0.02). Knee joint involvement caused disability most frequently. Cidx was higher in males (p=0.008). Minor correlation was found between Cidx with age, HAQ-DI & DAPSA. Mean BMI of our cohort was 26.8(±14.8) kg/m2. 56.5% were overweight. Higher BMI was not associated with age, duration of arthritis, DAPSA, PASI, HAQ-DI & Cidx.

Infections (any time) were recorded in 10.8%, of which skin was the commonest site in 38.9%; 30.5% of these needed hospitalizations.

Conclusion:

Despite mild skin disease in majority, more than half of the patients have moderate to severe joint activity. Mild to moderate functional disability in nearly half of our cohort indicate high burden of damage. High incidence of co-morbidities in PsA compared with general population is in line with published literature. In addition to aggressive control of articular activity, detection and control of co-morbidities must be an integral part of PsA management.

References:

[1]https://doi.org/10.1093/rheumatology/41.12.1457

[2]http://dx.doi.org/10.1136/annrheumdis-2016-eular.4598

Table 2.

Disease characteristics

DISEASE ACTIVITYDISABILITYCO-MORBIDITIESMean PASI: 3.8(7.4)Mean HAQ-DI: 0.3(0.45)Mean Cidx: 0.98(1.6)Mild (PASI 0-5)480(80%)Mild-mod disability260(48.2%)N with 1 or more CMs232(42.3%)Severe (>10)57(10.6%)ADL with most frequent disabilityClimbing a flight of stairs 189(35%)HTNT2DMSmokingPsA severity19.8%16.6%5.4%3.2%Mean DAPSA: 18.8(16.6)ADL with highest disability scoreSitting cross-legged/squattingAnxietyIHDDyslipidemiaOthers3.1%2.3%2%<2% eachRemission100(19.9%)Low DA145(28.8%)Moderate DA137(27.2%)High DA123(24.5%)Family h/o CV dis/stroke72(15.2%)

Disclosure of Interests:

None declared

Effect of ionic liquid on the fluorescence of an intramolecular exciplex forming probe

The effects of ionic liquid addition on the spectroscopic properties of a pyrene-tryptophan-containing fluorescent intramolecular complex in polar-aprotic and polar-protic solvents, specifically, acetonitrile and ethanol, are assessed. Two ionic liquid sets, consisting of seven different ionic liquids, were explored; set 1 comprised three imidazolium-containing ionic liquids paired with different anions while set 2 consisted of varying cations, namely, imidazolium, pyrrolidinium, ammonium, and pyridinium, partnered with a common anion, bis(trifluoromethylsulfonyl)imide ([Tf2N-]). The results provided herein reveal that all ionic liquids explored behave as quenchers, however, the imidazolium-, pyrrolidinium-, and ammonium-containing ionic liquids selectively quenched the fluorescence from the exciplex while the monomer emission from pyrene was largely unaffected relative to exciplex emission. Conversely, the pyridinium ionic liquid, significantly quenched the fluorescence from both the pyrene monomer and the pyrene-tryptophan exciplex, as was expected. The observed quenching is demonstrated to originate from the cations of the ionic liquids and is, in general, more efficient for an imidazolium ionic liquid that contains an acidic proton in the C2 position. Stern-Volmer plots of the exciplex quenching demonstrate a complex quenching mechanism that does not appear to follow any conventional quenching models with the data best fit to an exponential equation. Furthermore, time-resolved fluorescence measurements reveal that the quenching is not dynamic in nature as the recovered decay times do not systematically decrease with increasing ionic liquid concentration, suggesting a possible static quenching mechanism. Thus, the formation of a "dark" ensemble is proposed, in which the ionic liquid cations complex with or crowd around the exciplex, quenching the intramolecular energy transfer.

Unprecedented formation of reverse micellar vesicles from psuedopeptidic bottlebrush polymers

Self-assembly of psuedopeptidic polymers to vesicles is reported and the mechanism of this spherical assembly has also been delineated.

Revealing Signs and Hidden 1H NMR Coupling Constants in Three-Spin Systems Using Long-Lived Coherences

Long-lived coherences (LLCs) in a pair of coupled protons have long lifetimes and hence decreased line width and increased spectral resolution. Fourier transformation of the damped oscillatory decay of the LLC also provides coupling information on the spin system. In a three-spin system, unlike in the two-spin case, the peaks in an LLC spectrum are observed at combinations of the coupling constants. This attribute is used to determine the relative signs of the coupling constants in weakly and strongly coupled model systems. In addition, it is shown that a coupling constant in a three-spin system that is unobservable in the ¹H NMR spectrum, as is the case in bispidinone, a molecule of significance in peptidomimetics, may be determined from the LLC spectrum.

Glutamic acid-based dendritic peptides for scaffold-free cartilage tissue engineering

Current treatment modalities for cartilage regeneration often result in the production of fibrous-type cartilage tissue at the defect site, which has inferior mechanical properties as compared to native hyaline cartilage. Further, effective treatments are not available at present, for preventing age-related as well as disease-related hypertrophic development of chondrocytes. In the present study, we designed and synthesized three sets of glutamic acid-based dendritic peptides, differing in degree of lipidation as well as branching. Each set constitutes of N-terminal protected as well as corresponding N-deprotected peptides. Altogether, six peptides [BE12, E12, BE3(12)4, E3(12)4, BE3OMe, E3OMe] were tested for their chondrogenesis enhancing potential in vitro, using rabbit adipose derived mesenchymal stem cells (ADMSCs). Immunohistochemical and gene expression studies as well as biochemical analyses revealed that the lipopeptides [E12 and BE3(12)4] are able to enhance chondrogenic differentiation of ADMSCs significantly (p < 0.001) as compared to control group (chondrogenic medium alone). Glycosaminoglycan content, and the chondrogenic marker genes like Aggrecan (Acan), Type II collagen (Col2a1), Hyaluronan synthase 2 (Has2), and SRY-box 9 (Sox9) expressions were found to be significantly increased in E12 and BE3(12)4 treated groups. Most importantly, the BE3(12)4 treated group showed significantly lower Type I collagen (Col1a2) and Type X collagen (Col10a1) transcript levels (p < 0.001), indicating its potential for hyaline cartilage formation and also to prevent hypertrophic development. Thus, the lipopeptides E12 and BE3(12)4 may be useful for preventing chondrocyte hypertrophy and realizing the hyaline nature of regenerated cartilage tissue in tissue engineering. STATEMENT OF SIGNIFICANCE: The current treatment modalities for degenerative cartilage diseases are unsatisfactory as the resultant regenerated cartilage is often fibrous in nature with inferior mechanical properties. Further, there is no proper treatment available for age-related development of chondrocyte hypertrophy at present. In this study we synthesized glutamic acid-based lipopeptides, which differ in the degree of lipidation as well as branching. We used a combinatorial approach of scaffold-free tissue engineering and dendritic lipopeptides to achieve hyaline-like cartilage tissue from adipose derived mesenchymal stem cells in vitro. Gene expression analysis revealed the down regulation of fibrous cartilage marker Col1a2 and hypertrophic marker Col10a1, suggesting that these lipopeptides may be useful for achieving mechanically superior hyaline cartilage regeneration in future.

Designer Peptide and Protein Dendrimers: A Cross-Sectional Analysis

Dendrimers have attracted immense interest in science and technology due to their unique chemical structure that offers a myriad of opportunities for researchers. Dendritic design allows us to present peptides in a branched three-dimensional fashion that eventually leads to a globular shape, thus mimicking globular proteins. Peptide dendrimers, unlike other classes of dendrimers, have immense applications in biomedical research due to their biological origin. The diversity of potential building blocks and innumerable possibilities for design, along with the fact that the area is relatively underexplored, make peptide dendrimers sought-after candidates for various applications. This review summarizes the stepwise evolution of peptidic dendrimers along with their multifaceted applications in various fields. Further, the introduction of biomacromolecules such as proteins to a dendritic scaffold, resulting in complex macromolecules with discrete molecular weights, is an altogether new addition to the area of organic chemistry. The synthesis of highly complex and fully folded biomacromolecules on a dendritic scaffold requires expertise in synthetic organic chemistry and biology. Presently, there are only a handful of examples of protein dendrimers; we believe that these limited examples will fuel further research in this area.

Maximizing RNA Loading for Gene Silencing Using Porous Silicon Nanoparticles

Gene silencing by RNA interference is a powerful technology with broad applications. However, this technology has been hampered by the instability of small interfering RNA (siRNA) molecules in physiological conditions and their inefficient delivery into the cytoplasm of target cells. Porous silicon nanoparticles have emerged as a potential delivery vehicle to overcome these limitations-being able to encapsulate RNA molecules within the porous matrix and protect them from degradation. Here, key variables were investigated that influence siRNA loading into porous silicon nanoparticles. The effect of modifying the surface of porous silicon nanoparticles with various amino-functional molecules as well as the effects of salt and chaotropic agents in facilitating siRNA loading was examined. Maximum siRNA loading of 413 μg/(mg of porous silicon nanoparticles) was found when the nanoparticles were modified by a fourth generation polyamidoamine dendrimer. Low concentrations of urea or salt increased loading capacity: an increase in RNA loading by 19% at a concentration of 0.05 M NaCl or 21% at a concentration of 0.25 M urea was observed when compared to loading in water. Lastly, it was demonstrated that dendrimer-functionalized nanocarriers are able to deliver siRNA against ELOVL5, a target for the treatment of advanced prostate cancer.

Unprecedented Intramolecular Association-Induced Fluorescence in Tryptophan-Conjugated Peptidomimetics

We report herewith tryptophan (Trp)-conjugated peptidomimetics that show intramolecular through-space association between the Trp units. Our investigation revealed that the proximal placement of Trp can lead to the emergence of a new and unanticipated fluorescent entity constituting a Trp-Trp dimer. Proton-induced modulation of fluorescence is a consequence of this work. Investigations with control compounds unequivocally revealed that the fluorescence property is not originated from the localized excited state but from the unprecedented Trp-Trp intramolecular dimer in the ground state itself. The present findings will initiate the biophysical scientists to have a relook at the fluorescence properties of Trp-containing proteins.

Influence of disease duration and socioeconomic factors on the prevalence of infection and hospitalization in rheumatoid arthritis: KRAC study

AIM

The use of healthcare resources by rheumatoid arthritis (RA) patients can be related to the presence of disease, comorbid conditions, use of steroids, and the combined use of immunosuppressants. This study evaluated the risk factors associated with infection and hospitalization in RA.

METHODS

This multicenter, cross-sectional study enrolled 3247 RA subjects fulfilling the 2010 American College of Rheumatology/European League Against Rheumatism criteria to examine the prevalence of hospitalization and episodes of documentable non-tubercular infections as a part of the "Karnataka rheumatoid arthritis comorbidity" study (KRAC). The study included 2081 subjects and 1166 were excluded due to incomplete data. Demographic, clinical and treatment variables were collected, and the events related to infections and hospitalization were extracted from the medical records. Comparative analysis and multivariate logistic regression were performed.

RESULTS

Around 22% of the subjects had hospitalizations and 2.9% had infections. Infections were pertaining to dental (1.3%), urinary tract (1.6%) and candidiasis (0.2%). Skin- and soft tissue-related infections were found in 1.8% and 0.3% of patients, respectively. Increased need of hospitalization in RA patients was associated with advanced age (≥60 years), lower education, family income, and longer duration of RA. Presence of comorbidity, usage of three or more disease-modifying anti-rheumatic drugs (DMARDs) and family income influenced the likelihood of infection. Dental infections were less likely in working subjects and more likely in patients with increased disease duration, higher family income, comorbidities and those between the age group 40-59 years. Urinary tract infection was associated with DMARD usage.

CONCLUSION

Patient-specific risk factors should be considered to improve treatment strategies and to reduce the risk of infection and hospitalization in RA patients.

Prevalence and Clinical Use of Anti-Thyroid Antibodies in RA Patients: A Prospective Case-Control Study

AIM

To evaluate the prevalence of anti-thyroid antibodies in a cohort of rheumatoid arthritis (RA) patients from south India and their clinical use.

METHODS

A cross-sectional epidemiological study was conducted including 1217 patients aged more than 14 years with fever and thrombocytopenia admitted in the medical wards from October 2013 to September 2014. Detailed clinical examination and routine investigations were done; specific investigations like blood culture, widal test, antigen test for malaria, IgM ELISA leptospira, IgM ELISA dengue, bone marrow aspiration/biopsy etc. were done as and when indicated. The data are presented as percentage and numbers. Rates and ratios are computedThe prospective case-control study, conducted for 3 consecutive months in a tertiary care hospital based in India, evaluated 103 RA patients (active group) and 36 age-matched healthy controls without the disease. Both the control and active groups were compared for thyroid autoantibodies, and the clinical evaluation included assessment of swollen joint counts (SJC), tender joint counts (TJC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), pain scale, disease activity score (DAS), rheumatoid factor (RF), anti-nuclear antibody (ANA) and anti-cyclic citrullinated peptide (anti-CCP). The active group subjects were further subdivided into RA patients with and without hypothyroidism, and were compared for normal and abnormal levels of thyroid autoantibodies and the variations were statistically analysed.

RESULTS

The corresponding mean age of the subjects belonging to the active and control groups were 47.09±11.29 and 41.03±11, with a female to male ratio of 1:0.12 and 1:0.29 respectively. Among the various thyroid autoantibodies compared between the active and control groups, a significant correlation (P=0.00936) was observed for anti-TTG antibodies. Also, the study has noted a significantly elevated level of anti-TPO antibodies in RA patients with hypothyroidism compared to the group without hypothyroidism (P=0.0074).

CONCLUSION

A significantly increased level of anti-TPO antibodies was noted in RA patients with hypothyroidism.

Comorbidities and related factors in rheumatoid arthritis patients of south India- Karnataka Rheumatoid Arthritis Comorbidity (KRAC) study

The aim was to study the prevalence of comorbidities in rheumatoid arthritis (RA) patients in everyday clinical practice and their association with disease-specific and demographic factors. The multi-center study recruited 3,247 (at 14 centers, and 265) were excluded due to incomplete data. The number of subjects considered for the analysis was 2982. The mean (±standard deviation) age was 48.98±12.64 years and the male-to-female ratio was 1:5. The data was collected based on a pre-structured pro forma by trained clinical research associates through interview and verification of charts and reports available in the patient records. The following comorbidities were studied: cardiovascular disease, hypertension, diabetes mellitus, hypercholesterolemia, thyroid disease, psychiatric diseases like depression, and pulmonary disease. Hypertension (20.7%), diabetes mellitus (14.4%) and thyroid disease (18.3%) were the most prevalent comorbidities. Hypercholesterolemia (5.3%), pulmonary diseases (2.1%), cardiovascular diseases (0.2%) and depression (0.03%) were prevalent in ≤5% of the study population. The overall presence of comorbidity increased with age and reduced with the duration of illness prior (DOIP). The age, gender, and DOIP differed significantly between groups with and without hypercholesterolemia. Females had a statistically increased prevalence of thyroid disease. The prevalence of comorbidities in RA patients from south India is around 40% and the incidence of comorbidity increased with age. As per the literature evidence, the prevalence in the current study subjects was higher when compared to prevalence of similar diseases occurring in the general south Indian population.