Recent Updates in Understanding NSAID Hypersensitivity.

PURPOSE OF REVIEW: To provide a review of available literature regarding nonsteroidal anti-inflammatory drug (NSAID) hypersensitivity with an emphasis on more recent findings. RECENT FINDINGS: Oral provocation tests with aspirin are important for diagnosis and management in adult and pediatric populations with reported NSAID hypersensitivity. Risk of cross-reactivity to COX-2 inhibitors varies by NSAID hypersensitivity phenotype. COX-2 inhibitors are tolerated in aspirin-exacerbated respiratory disease. Reported NSAID allergy is associated with a higher risk of a substance use disorder. Effective treatment of underlying chronic spontaneous urticaria can allow tolerance of NSAIDs in NSAID-exacerbated cutaneous disease. The pathophysiology, cross-reactivity, and appropriate diagnostic evaluation differ between the 5 distinct NSAID hypersensitivity phenotypes. Further research into the pathophysiology of NSAID hypersensitivity in patients with and without underlying disease is needed.

Acetylsalicylic acid (ASA) desensitization in an allergic pregnant woman post-vascular scaffolds implantation.

Summary: The use of acetylsalicylic acid (ASA) desensitization for patients with coronary artery disease (CAD) is growing, but no data are available on desensitization protocol in patients with ASA sensitivity and CAD during pregnancy. This case report shows that ASA desensitization protocol during pregnancy could be safe and effective in a tertiary centre with a multidisciplinary team.

Clinical evaluation and diagnosis of aspirin-exacerbated respiratory disease.

Aspirin-exacerbated respiratory disease (AERD) is a condition composed of chronic rhinosinusitis with nasal polyposis and asthma that is defined by respiratory hypersensitivity reactions to the cyclooxygenase 1-inhibitory effects of nonsteroidal anti-inflammatory drugs. It is diagnosed in 5% to 15% of patients with asthma and is even more common in those with comorbid nasal polyposis. Diagnosis is confirmed after an aspirin challenge procedure, yet many patients present with all components and can reliably be diagnosed by history. Patients with AERD commonly experience severe uncontrolled nasal polyposis and require multispecialty evaluation to properly stage and treat this condition. The presence of nasal polyposis plays a large component in the diminished quality of life in patients with AERD. In the last decade, multiple new therapeutic areas have been approved for type 2 airway diseases, offering patients with AERD many more options for control. This makes an early and accurate diagnosis of AERD important in the care of the larger population of type 2 airway diseases.

Selective COX-2 inhibitor continues to be a safe alternative in patients with nonselective NSAIDs hypersensitivity.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) cause different types of allergic and pseudo allergic reactions. This results in difficulties in clinical practice. Most cases of NSAID hypersensitivity are mediated by the inhibition of cyclooxygenase-1 enzyme (COX-1), which results in depletion of the protective prostaglandin E2, and promotes the unrestrained synthesis of inflammatory mediators from mast cells. Selective COX-2 inhibitors are considered safe alternatives in patients with NSAID allergy, although hypersensitivity reactions to COX-2 inhibitors have also been reported. Our study aimed to report the experience in Qatar for using COX2 inhibitors as an alternative treatment for nonselective NSAID allergy. METHODS: Data of patients who underwent open challenge with a single dose of oral celecoxib 200 mg were retrieved from the procedure log of the Allergy and immunology Division in Hamad medical corporation, Doha, Qatar, from 2013 to 2022. The challenge was considered positive if the patient developed cutaneous or respiratory symptoms. RESULTS: A total of 31 patients were identified; 4 with a history of celecoxib allergy. The remaining 27 (23 females and 4 males); with mean ( ± SD, range) age of 42 ( ± 12, 20-65) years had hypersensitivity to one (n = 11) or more than one (n = 16) nonselective NSAID, manifested as cutaneous, respiratory, or anaphylactic symptoms. Those 4 patients with celecoxib allergy were challenged and only one with a historical reaction of anaphylaxis developed anaphylaxis during the challenge. Celecoxib was well tolerated in all 27 patients with hypersensitivity reactions to nonselective NSAIDs. Also, patients were contacted by telephone call at 24 hours and after 1 week with no evidence of delayed reactions. CONCLUSIONS: Selective COX-2 and nonselective NSAIDs have similar overall efficacy as analgesic, anti-inflammatory, and antipyretic agents. Hypersensitivity reaction to COX-2 inhibitors has been reported; however, it is rare. So, it is safer to challenge the patients with COX-2 inhibitors before prescribing them as alternative medication in patients with Nonselective NSAID allergies. We plan to conduct a single-/double-blind placebo-controlled study for more patients, especially using graded challenges for high-risk profile candidates. Also, it may be of significance to test more than one type of selective COX-2 to avoid drug-specific reactions.

[The differential diagnosis of adverse reactions to non-steroidal anti-inflammatory drugs. In vitro and in vivo methods]. / Nemszteroid gyulladáscsökkentok okozta adverz reakciók differenciáldiagnosztikája. In vitro és in vivo módszerek.

INTRODUCTION: According to the present knowledge, the effect of non-steroidal anti-inflammatory drugs (NSAIDs) depends on the inhibitory ratio of cyclooxigenase (COX)-1 to COX-2 in the plasma membranes. In addition to cardiovascular and gastrointestinal side effects, there are adverse symptoms which can be divided into cross-intolerance (non-immune mediated) and single or multiple hypersensitive (immune mediated) reactions. Due to clinical phenotypes and to in vivo aspirin reactivity, adverse effects could be further classified. AIM: The aim of these studies was a comparison of hit ratios obtained by a humoral serum test measuring specific immunglobulin E (IgE) against a rapid cellular test measuring interleukin (IL)-6 release from sensitized mononuclear cells due to various suspect NSAID after symptoms within one year. Retrospective case studies were performed in in- and out-patients of our teaching hospital in Budapest, between 2003 and 2013. METHOD: Specific anti-NSAID IgE levels were determined by ELISA in 55 cases. The other matching group of patients consisted of 51 patients and 9 tolerant persons. Their separated cells' supernatants were checked for IL-6 release incubated for 20 minutes by NSAID dilutions including intraassay controls by two-step ELISA assay. Both groups have been stratified according to "new" clinical classification. RESULTS: Results have disclosed no significant differences among the distribution of clinical symptoms between the two groups. In both groups, 9 non-steroidal anti-inflammatory drugs were tested representing all frequently used compounds with COX-1 inhibitory potential. The overall positivity rate was nearly double (65.4% against 36.9%) within the group using IL-6 release assay against that with specific IgE as the diagnostic tool. In certain cases, non-drug components of commercial preparations prompted IL-6 release as well which was paralleled by in vivo test results. Positive in vitro tests were obtained in both groups with clinically cross-intolerant as well as single or multiple sensitized cases. CONCLUSION: The rates of single or multiple sensitized cases exceeded in both groups that of cross-intolerant patients. In some phenotypes belonging to the latter categories, IgE type antibodies against acetylsalicylic acid could be detected as well. IL-6 release assay was the more sensitive test. In addition to pure drugs, other ingredients of medicines could also be responsible for adverse events. Orv Hetil. 2018; 159(38): 1556-1566.

Immediate Reactions to More Than 1 NSAID Must Not Be Considered Cross-Hypersensitivity Unless Tolerance to ASA Is Verified.

BACKGROUND AND OBJECTIVES: Individuals who develop drug hypersensitivity reactions (DHRs) to chemically unrelated nonsteroidal anti-inflammatory drugs (NSAIDs) are considered cross-hypersensitive. The hallmark for this classification is that the patient presents a reaction after intake of or challenge with acetylsalicylic acid (ASA). Whether patients react to 2 or more NSAIDs while tolerating ASA remains to be studied (selective reactions, SRs). Objective: To identify patients with SRs to 2 or more NSAIDs including strong COX-1 inhibitors. METHODS: Patients who attended the Allergy Service of Hospital Infanta Leonor, Madrid, Spain with DHRs to NSAIDs between January 2011 and December 2014 were evaluated. Those with 2 or more immediate reactions occurring in less than 1 hour after intake were included. After confirming tolerance to ASA, the selectivity of the response to 2 or more NSAIDs was demonstrated by in vivo and/or in vitro testing or by controlled administration. RESULTS: From a total of 203 patients with immediate DHRs to NSAIDs, 16 (7.9%) met the inclusion criteria. The patients presented a total of 68 anaphylactic or cutaneous reactions (mean [SD], 4.2 [2.1]). Most reactions were to ibuprofen and other arylpropionic acid derivatives and to metamizole. Two different NSAIDs were involved in 11 patients and 3 in 5 patients. CONCLUSIONS: Patients with NSAID-induced anaphylaxis or urticaria/angioedema should not be considered cross-hypersensitive unless tolerance to ASA is verified.

Single NSAID hypersensitivity is associated with atopic status.

BACKGROUND: The relationship between hypersensitivity to NSAID and atopic status is still incompletely defined. Previous studies found a high prevalence of atopic diseases in multiple NSAID reactors. The present study aimed to investigate whether this is the case also in Italian adults hypersensitive to NSAIDs. METHODS: Skin tests with a large panel of seasonal and perennial airborne allergens were carried out in 252 patients with a clear-cut history of acute urticaria induced by nonsteroidal anti-inflammatory drugs. Patients were classified as single or multiple NSAID reactors based on clinical history, presence/absence of chronic urticaria, re-challenge with the reported offending drug in case of doubt history, and oral challenges with aspirin or propionic acid derivatives. RESULTS: Single NSAID reactors showed a much higher prevalence of atopic diseases than multiple NSAID reactors either with or without chronic urticaria (61% vs 19% and 19%, respectively; p < 0.001). CONCLUSION: As a difference from previous reports, in Italian patients hypersensitive to NSAID atopy is much more prevalent among single reactors, a finding that indirectly supports the possible IgE-mediated origin of this type of adverse drug reaction.

Genetic Susceptibility of HLA Alleles to Non-Steroidal Anti-Inflammatory Drug Hypersensitivity in the Taiwanese Population.

BACKGROUND: Human leukocyte antigen (HLA) genes are important in many immune processes and contribute to many adverse drug reactions. Whether genetic variations in the HLA region are associated with non-steroid anti-inflammatory drug (NSAID) hypersensitivity remains uncertain. Therefore, the aim of our study was to identify HLA genetic variations in patients with NSAID hypersensitivity in the Taiwanese population. METHODS: This hospital-based, retrospective case-control study enrolled 37,156 participants with NSAID exposure from the Taiwan Precision Medicine Initiative (TPMI), who were all genotyped and imputed to fine map HLA typing. Our study assigned 1217 cases to the NSAID allergy group and 12,170 controls to a matched group. Logistic regression analyses were utilized to explore associations between HLA alleles and NSAID hypersensitivity. RESULTS: Overall, 13,387 patients were genotyped for eight major HLA alleles. Allele frequencies were different between the two groups. In the NSAID allergy group, the genotype frequencies of HLA-A*02:01, HLA-A*34:01, and HLA-DQA1*06:01 were found to be markedly elevated compared to the control group, a significance that persisted even after applying the Bonferroni correction. Furthermore, the risk of NSAID allergy demonstrated a significant association with HLA-A*02:01 (OR = 1.29, p < 0.001) and HLA-A*34:01 (OR = 9.90, p = 0.001), in comparison to their respective counterparts. Notably, the genotype frequency of HLA-B*46:01 exhibited a significant increase in the severe allergy group when compared with the mild allergy group. CONCLUSIONS: We identified HLA genotypes linked to the onset and severity of NSAID hypersensitivity. Our findings establish a basis for precision prescription in future clinical applications.

Sex, Ethnicity, Body Mass Index, and Environmental Exposures Associated With NSAID-Exacerbated Respiratory Disease Symptom Sequence.

BACKGROUND: Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (N-ERD) has a triad of symptoms: nasal polyposis, asthma, and NSAID hypersensitivity. Little is known about symptom timing and disease progression. OBJECTIVE: The aim of this study is to characterize disease progression in N-ERD. METHODS: Patients with N-ERD were prospectively interviewed and classified into 4 groups based on their first symptom at initial N-ERD onset (asthma, nasal polyps, NSAID hypersensitivity, or all concurrently). Associations of patient characteristics with the 4 groups were examined, along with associations within the "asthma first" group. RESULTS: Patients (N = 240) were mostly female (68%) and self-identified as non-White (77%). Half (N = 119) reported asthma as the earliest symptom in the N-ERD triad. Compared with other groups, "asthma first" was associated with younger age of onset (25 years, standard error ±1.3, P < .001) and higher body mass index (BMI) (odds ratio [OR] = 1.3, 95% confidence interval [CI]: 1.06-1.7, P = .02). In this group, age of onset <20 years was associated with female sex, Latino ethnicity, and higher BMI (all P < .05). The "NSAID sensitivity first" group was significantly associated with male sex (OR = 3.3, 95% CI: 1.5-7.4, P = .004) and pollution exposure (OR = 4.4, 95% CI: 1.6-11.9, P = .003). At the initial presentation, 27% of patients were unaware of their N-ERD diagnosis. Black and Latino patients were more likely to be unaware of their N-ERD diagnosis compared with White (P = .003). The median diagnostic delay was 3 years (interquartile range: 0-5 years). CONCLUSIONS: In this cohort, N-ERD is highly variable in onset and progression, with sex, BMI, race and ethnicity, and environmental exposures significantly associated with disease patterns and diagnostic delay.

Hypersensitivity reactions to nonsteroidal anti-inflammatory drugs: does age matter?

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) are reported to be the leading cause of drug hypersensitivity reactions. The aim of this study was to characterize a cohort of patients with NSAID hypersensitivity and establish if there are any differences between two groups of adult patients, under 55 years old and over 55 years old, and identify safe alternative options. METHODS: Patients with NSAID hypersensitivity who were referred to a single tertiary Allergy center from January 2019 to December 2021 were included. Clinical information was obtained from a review of medical records. RESULTS: A total of 135 patients with a history of NSAID-induced hypersensitivity reactions were included, 80 patients under 55 years old and 55 patients older than 55. Most of the patients enrolled were female (80.74%) and the mean age was 50.21 years, ranging from 18 to 78 years old. The time interval between the first reaction and the allergy work-up was longer in the older group (average timeframe 6.87 years) than in the younger group (average timeframe 3.77 years). The main culprit was metamizole in both groups. An oral provocation test to paracetamol was performed in most of the patients who tolerated the intake of 1000 mg, except for 2 patients who developed angioedema. CONCLUSION: Angioedema was the most encountered symptom in our population. Age does not influence the allergy work-up of patients with a history of NSAID-induced hypersensitivity reactions. The drug provocation challenge remains the gold standard for finding a suitable alternative in patients with NSAID-induced hypersensitivity.

Polymorphisms in Human IL4, IL10, and TNF Genes Are Associated with an Increased Risk of Developing NSAID-Exacerbated Respiratory Disease.

BACKGROUND: The role of genetics in non-steroidal anti-inflammatory drugs (NSAID) exacerbated respiratory disease (NERD) is unclear, with different candidates involved, such as HLA genes, genes related to leukotriene synthesis, and cytokine genes. This study aimed to determine possible associations between 22 polymorphisms in 13 cytokine genes. METHODS: We included 195 patients (85 with NERD and 110 with respiratory disease who tolerate NSAIDs) and 156 controls (non-atopic individuals without a history of asthma, nasal polyposis (NP), or NSAID hypersensitivity). Genotyping was performed by sequence-specific primer polymerase chain reaction (PCR-SSP). Amplicons were analyzed by horizontal gel electrophoresis in 2% agarose. RESULTS: Significant differences in allele and genotype frequency distributions were found in TNF (rs1800629), IL4 (rs2243248 and rs2243250), and IL10 (rs1800896, rs1800871, and rs1800872) genes in patients with NSAID hypersensitivity. In all cases, the minor allele and the heterozygous genotype were more prevalent in NERD. An association of TNF rs1800629 SNP with respiratory disease in NSAID-tolerant patients was also found. CONCLUSIONS: Retrospectively recorded, we found strong associations of NERD with polymorphisms in IL4, IL10, and TNF genes, suggesting that these genes could be involved in the inflammatory mechanisms underlying NERD.

The Role of Omalizumab in NSAID-Exacerbated Respiratory Disease: A Narrative Review.

Nonsteroidal anti-inflammatory drug-exacerbated respiratory disease (N-ERD) is a condition characterized by the triad of chronic rhinosinusitis with nasal polyps, bronchial asthma, and hypersensitivity to nonsteroidal anti-inflammatory drugs. This article explores the current knowledge on the various pathological mechanism(s) of N-ERD-such as arachidonic acid metabolism, cysteinyl leukotrienes, prostaglandins, platelets, IgE, mast cells, eosinophils, basophils, and innate immune system-and the role of omalizumab in its management. The authors dive deep into the role of IgE in N-ERD and its potential as a therapeutic target. IgE plays a significant role in mediating allergic reactions, is intricately linked with mast cells, interacts with multiple immunopathological pathways involved in N-ERD, and tends to be elevated in patients with N-ERD. Multiple real-world studies, observational studies, and case series, as well as 2 phase III trials, have demonstrated the effectiveness of omalizumab in the management of N-ERD. For a disease with such a well-documented history, the pathophysiology of N-ERD and the most effective ways to manage it remain a mystery. With this background, the authors ask-is IgE a missing piece of the N-ERD puzzle, thus explaining the efficacy of omalizumab in the treatment of the disease?

The importance of timely diagnosis of aspirin-exacerbated respiratory disease for patient health and safety.

BACKGROUD: Aspirin-exacerbated respiratory disease (AERD) is a difficult-to-treat syndrome where timely diagnosis and initiation of disease-specific therapies are pertinent to improved patient outcomes. OBJECTIVE: To characterize the most common timeline for development of the clinical triad [asthma, nasal polyposis, and reactions to nonsteroidal anti-inflammatory drugs (NSAIDs)], identify barriers to prompt diagnosis of AERD, and describe indications for an aspirin challenge to facilitate accurate diagnosis. METHODS: Six hundred ninety-seven patients with diagnosed AERD and history of at least one sinus surgery to remove nasal polyps were identified in the Brigham and Women's Hospital AERD registry. Patient reported age at disease onset of asthma, nasal polyposis, and age of first NSAID reaction were obtained from 2013 to 2019 at enrollment. RESULTS: Of the 697 patients identified, diagnosis of asthma preceded diagnosis of nasal polyposis and first NSAID reaction, although there was considerable variability between patients. CONCLUSIONS: Prompt diagnosis of AERD is important for patient and provider education and improved care of this difficult-to-treat population of patients. Consider diagnostic aspirin challenge in patients without historical reactions to NSAIDs who have an otherwise compatible clinical history, specifically in patients who take daily low-dose aspirin, leukotriene modifiers, avoid NSAIDs, or who are severely symptomatic at baseline where it would be difficult to identify an acute worsening of symptoms.

Complementary Participation of Genetics and Epigenetics in Development of NSAID-exacerbated Respiratory Disease.

Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (NERD) has attracted a great deal of attention because of its association with severe asthma. However, it remains widely underdiagnosed in asthmatics as well as the general population. Upon pharmacological inhibition of cyclooxygenase 1 by NSAIDs, production of anti-inflammatory prostaglandin E2 and lipoxins ceases, while release of proinflammatory cysteinyl leukotrienes increases. To determine the underlying mechanisms, many studies have attempted to elucidate the genetic variants, such as single nucleotide polymorphisms, responsible for alterations of prostaglandins and leukotrienes, but the results of these genetic studies could not explain the whole genetic pathogenesis of NERD. Accordingly, the field of epigenetics has been introduced as an additional contributor to genomic alteration underlying the development of NERD. Recently, changes in CpG methylation, as one of the epigenetic components, have been identified in target tissues of NERD. This review discusses in silico analyses of both genetic and epigenetic components to gain a better understanding of their complementary roles in the development of NERD. Although the molecular mechanisms underlying NERD pathogenesis remain poorly understood, genetic and epigenetic variations play significant roles. Our results enhance the understanding of the genetic and epigenetic mechanisms involved in the development of NERD and suggest new approaches toward better diagnosis and management.

Acetyl Salicylic Acid Challenge in Children with Hypersensitivity Reactions to Nonsteroidal Anti-Inflammatory Drugs Differentiates Between Cross-Intolerant and Selective Responders.

BACKGROUND: Hypersensitivity reactions to nonsteroidal anti-inflammatory drugs (NSAIDs) in children are becoming a great concern. Most studies have focused on adults, with noted discrepancies observed in the classification of hypersensitivity reactions to NSAIDs in children when compared with adults. OBJECTIVE: To phenotype a group of children with hypersensitivity reactions to NSAIDs, including paracetamol, and analyze the degree of agreement with the entities reported in adults and how they fit the proposed classifications. METHODS: The study comprised 116 children aged 0.5 to 14 years, with a clinical history indicative of hypersensitivity reactions to NSAIDs. They all underwent a single-blind oral provocation test with acetyl salicylic acid, except in those cases when this was the suspected drug, in which case the challenge was done first with ibuprofen. If positive, cross-intolerance was established and if negative, an oral provocation test with the culprit drug was performed to establish a selective response or exclude allergy. RESULTS: Of the 26% diagnosed as hypersensitive to NSAIDs, 83% were cross-intolerant and 17% selective reactors. The highest significant differences between reactors and nonreactors were observed in the time to reaction after drug intake and the clinical entity (P < .0001), followed by drug involved and age (P < .01). CONCLUSIONS: From the total number of cases confirmed with NSAID hypersensitivity, 83% were cross-intolerant. In cross-intolerant reactions, both cutaneous and respiratory manifestations are common. Acetyl salicylic acid challenge as the first approach proved to be safe and useful to establish the diagnosis.

NSAID hypersensitivity - recommendations for diagnostic work up and patient management.

BACKGROUND: Adverse drug reactions (ADR) to analgesics (i.e., non-steroidal anti-inflammatory drug hypersensitivity, NSAID-HS) are one of the most common ADR, affecting approximately 1.6% of all patients. Despite the fact that they are common, they still pose a diagnostic challenge. METHODS: This article is an overview of selected scientific articles and is based on research in PubMed, specialist databases, and guidelines. RESULTS: Approximately 80% of side effects are pharmacologically predictable and are classified as type A reactions, such as abdominal pain and bleeding events. More advanced diagnostic investigations are not useful in such cases. Type B reactions, which account for the remaining 20%, are subdivided into the far more frequent cross-reactive, non-immunological NSAID-HS (acronyms NERD [NSAID exacerbated respiratory disease], NECD [NSAID exacerbated cutaneous disease], NIUA [NSAID-induced urticaria/angioedema]) and the much rarer true drug allergies of type I and IV (acronyms SNIUAA [single NSAID-induced urticara/angioedema or anaphylaxis] and SNIDR [single NSAID-induced delayed reaction]). The two latter are not cross-reactive and all other NSAIDs are generally well tolerated. CONCLUSION: The diagnostic work-up begins with a detailed patient's history. Skin tests are only useful in SNIDR and SNIUAA, while in vitro tests are helpful merely in exceptional cases. In general, the diagnosis can only be confirmed by provocation testing, when required. Although cross-reactivity is usually present, provocation testing is often able to find an alternative, tolerable analgesic. Individual patient management usually enables a solution to be found for most patients.

Pharmacogenomics of Prostaglandin and Leukotriene Receptors.

Individual genetic background together with environmental effects are thought to be behind many human complex diseases. A number of genetic variants, mainly single nucleotide polymorphisms (SNPs), have been shown to be associated with various pathological and inflammatory conditions, representing potential therapeutic targets. Prostaglandins (PTGs) and leukotrienes (LTs) are eicosanoids derived from arachidonic acid and related polyunsaturated fatty acids that participate in both normal homeostasis and inflammatory conditions. These bioactive lipid mediators are synthesized through two major multistep enzymatic pathways: PTGs by cyclooxygenase and LTs by 5-lipoxygenase. The main physiological effects of PTGs include vasodilation and vascular leakage (PTGE2); mast cell maturation, eosinophil recruitment, and allergic responses (PTGD2); vascular and respiratory smooth muscle contraction (PTGF2), and inhibition of platelet aggregation (PTGI2). LTB4 is mainly involved in neutrophil recruitment, vascular leakage, and epithelial barrier function, whereas cysteinyl LTs (CysLTs) (LTC4, LTD4, and LTE4) induce bronchoconstriction and neutrophil extravasation, and also participate in vascular leakage. PTGs and LTs exert their biological functions by binding to cognate receptors, which belong to the seven transmembrane, G protein-coupled receptor superfamily. SNPs in genes encoding these receptors may influence their functionality and have a role in disease susceptibility and drug treatment response. In this review we summarize SNPs in PTGs and LTs receptors and their relevance in human diseases. We also provide information on gene expression. Finally, we speculate on future directions for this topic.