A score for predicting colchicine resistance at the time of diagnosis in familial Mediterranean fever: data from the TURPAID registry

OBJECTIVES

Colchicine forms the mainstay of treatment in FMF. Approximately 5-10% of FMF patients are colchicine resistant and require anti-IL-1 drugs. We aimed to compare the characteristics of colchicine-resistant and colchicine-responsive patients and to develop a score for predicting colchicine resistance at the time of FMF diagnosis.

METHODS

FMF patients (0-18 years) enrolled in the Turkish Paediatric Autoinflammatory Diseases (TURPAID) registry were included. The predictive score for colchicine resistance was developed by using univariate/multivariate regression and receiver operating characteristics analyses.

RESULTS

A total of 3445 FMF patients [256 (7.4%) colchicine-resistant and 3189 colchicine-responsive) were included (female:male ratio 1.02; median age at diagnosis 67.4 months). Colchicine-resistant patients had longer, more frequent attacks and were younger at symptom onset and diagnosis (P < 0.05). Fever, erysipelas-like erythema, arthralgia, arthritis, myalgia, abdominal pain, diarrhoea, chest pain, comorbidities, parental consanguinity and homozygosity/compound heterozygosity for exon 10 MEFV mutations were significantly more prevalent among colchicine-resistant than colchicine-responsive patients (P < 0.05). Multivariate logistic regression analysis in the training cohort (n = 2684) showed that age at symptom onset, attack frequency, arthritis, chest pain and having two exon 10 mutations were the strongest predictors of colchicine resistance. The score including these items had a sensitivity of 81.3% and a specificity of 49.1%. In the validation cohort (n = 671), its sensitivity was 93.5% and specificity was 53.8%.

CONCLUSION

We developed a clinician-friendly and practical predictive score that could help us identify FMF patients with a greater risk of colchicine resistance and tailor disease management individually at the time of diagnosis.

The pyrin inflammasome, a leading actor in pediatric autoinflammatory diseases

The activation of the pyrin inflammasome represents a highly intriguing mechanism employed by the innate immune system to effectively counteract pathogenic agents. Despite its key role in innate immunity, pyrin has also garnered significant attention due to its association with a range of autoinflammatory diseases (AIDs) including familial Mediterranean fever caused by disruption of the MEFV gene, or in other genes involved in its complex regulation mechanisms. Pyrin activation is strictly dependent on homeostasis-altering molecular processes, mostly consisting of the disruption of the small Ras Homolog Family Member A (RhoA) GTPases by pathogen toxins. The downstream pathways are regulated by the phosphorylation of specific pyrin residues by the kinases PKN1/2 and the binding of the chaperone 14-3-3. Furthermore, a key role in pyrin activation is played by the cytoskeleton and gasdermin D, which is responsible for membrane pores in the context of pyroptosis. In addition, recent evidence has highlighted the role of steroid hormone catabolites and alarmins S100A8/A9 and S100A12 in pyrin-dependent inflammation. The aim of this article is to offer a comprehensive overview of the most recent evidence on the pyrin inflammasome and its molecular pathways to better understand the pathogenesis behind the significant group of pyrin-related AIDs.

PREDICT-crFMF score: A novel model for predicting colchicine resistance in children with familial Mediterranean fever

OBJECTIVES

To develop a novel scoring system to predict colchicine resistance in Familial Mediterranean fever (FMF) based on the initial features of the patients.

METHODS

The medical records of patients were analyzed prior to the initiation of colchicine. After generating a predictive score in the initial cohort, it was applied to an independent cohort for external validation of effectiveness and reliability.

RESULTS

Among 1418 patients with FMF, 56 (3.9%) were colchicine resistant (cr) and 1312 (96.1%) were colchicine responsive. Recurrent arthritis (4 points), protracted febrile myalgia (8 points), erysipelas-like erythema (2 points), exertional leg pain (2 points), and carrying M694V homozygous mutation (4 points) were determined as the parameters for predicting cr-FMF in the logistic regression model. The cut-off value of 9 was 87% sensitive and 82% specific to foresee the risk of cr-FMF in the receiver operating characteristic. Validation of the scoring system with an independent group (cr-FMF = 107, colchicine responsive = 1935) revealed that the cut-off value was 82% sensitive and 79% specific to identify the risk of cr-FMF.

CONCLUSIONS

By constructing this reliable and predictor tool, we enunciate that predicting cr-FMF at the initiation of the disease and interfering timely before the emergence of complications will be possible.

Genotype-Phenotype Associations of Children With Familial Mediterranean Fever in a Cohort Consisting of M694V Mutation and Implications for Colchicine-Resistant Disease

OBJECTIVES

The aim of this study was to investigate the clinical associations of the second allele mutations and the effect of genotype and presenting features on colchicine resistance in children with familial Mediterranean fever (FMF), carrying at least one M694V variant.

METHODS

The medical records of the patients diagnosed with FMF, in whom at least one allele M694V mutation was detected, were reviewed. Patients were grouped according to the genotype as M694V homozygotes, compound heterozygote M694V with an exon 10 mutation, compound heterozygote M694V with a variant of unknown significance (VUS), and M694V heterozygotes. Disease severity was assessed with the International Severity Scoring System for FMF.

RESULTS

Among the 141 patients included, homozygote M694V (43.3%) was the most frequent MEFV genotype. Clinical manifestations of FMF at diagnosis were not significantly different according to genotypic alterations except homozygote M694V. Besides, homozygous M694V was associated with a more severe disease, with more frequent comorbidities and colchicine-resistant disease. A lower disease severity score was observed in compound heterozygotes with VUS than in M694V heterozygotes (median 1 vs 2, p = 0.006). Regression analysis revealed that homozygous M694V, arthritis, and frequency of attacks were associated with an increased risk of colchicine-resistant disease.

CONCLUSIONS

Clinical manifestations of FMF at diagnosis with a M694V allele were predominantly influenced by the M694V rather than the second allele mutations. Although homozygous M694V was associated with the most severe form, the presence of compound heterozygosity with a VUS did not affect disease severity or clinical features. Homozygous M694V confers the highest risk of colchicine-resistant disease.

Renal involvement in monogenic autoinflammatory diseases: A narrative review

Autoinflammatory diseases (AIDs) are mostly caused by dysfunctions in single genes encoding for proteins with a prominent role in the regulation of innate immunity, such as complement factors, inflammasome components, tumour necrosis factor (TNF)-α, and proteins belonging to type I-interferon (IFN) signalling pathways. Due to the deposition of amyloid A (AA) fibrils in the glomeruli, unprovoked inflammation in AIDs frequently affects renal health. In fact, secondary AA amyloidosis is the most common form of amyloidosis in children. It is caused by the extracellular deposition of fibrillar low-molecular weight protein subunits resulting from the degradation and accumulation of serum amyloid A (SAA) in numerous tissues and organs, primarily the kidneys. The molecular mechanisms underlying AA amyloidosis in AIDs are the elevated levels of SAA, produced by the liver in response to pro-inflammatory cytokines, and a genetic predisposition due to specific SAA isoforms. Despite the prevalence of amyloid kidney disease, non-amyloid kidney diseases may also be responsible for chronic renal damage in children with AIDs, albeit with distinct characteristics. Glomerular damage can result in various forms of glomerulonephritis with distinct histologic characteristics and a different underlying pathophysiology. This review aims to describe the potential renal implications in patients with inflammasomopathies, type-I interferonopathies, and other rare AIDs in an effort to improve the clinical course and quality of life in paediatric patients with renal involvement.

Renal involvement, presence of amyloidosis, and genotype-phenotype relationship in pediatric patients with Familial Mediterranean fever: a single center study

The aim of the study is to investigate how renal involvement is correlated with frequency of amyloidosis, risk factors, and demographic and clinical characteristics in pediatric patients with Familial Mediterranean fever (FMF). Demographic and clinical characteristics and laboratory data of the pediatric patients diagnosed with FMF between 1990 and 2018 were recorded from their files. The diagnosis of patients with amyloidosis (AA) was proven by renal biopsy, and as for patients with non-amyloidosis renal involvement (RI wo AA), amyloidosis could not be detected but they were followed up with the diagnosis of proteinuria and/or hematuria. A total of 1929 FMF pediatric patients were included in the study. About 962 (49.9%) participants were male. There were 134 (6.9%) patients with RI wo AA and 23 (1.2%) patients with AA diagnosed by biopsy. The most common M694V heterozygous/homozygous(het/hom) (31%) mutation was observed. Delay in diagnosis and presence of colchicine resistance were more in patients with RI wo AA and AA (p < 0.05). M694V het/hom mutation was high in both RI wo AA and AA, while the presence of compound heterozygous with M694V mutation was high in RI wo AA (p < 0.01, p = 0.02, p = 0.048, respectively). There was a positive correlation between M694V mutation and monoarthritis/polyarthritis, between compound heterozygous with M694V mutations and presence of chest pain, and between V726A mutation and constipation. Also a negative correlation was found between E148Q and chest pain and between R202Q mutation and monoarthritis/polyarthritis. While M694V mutation increased the risk 2.6 times for AA and 1.7 times for RI wo AA, colchicine resistance increased the risk 33 times for AA and 25 times for RI wo AA.    Concluson: It was concluded in the present study that M694V mutation and colchicine resistance were two important risk factors for RI wo AA (6.9%) and amyloidosis (1.2%) in FMF patients. It should be kept in mind that compound heterozygous with M694V mutations may be associated with chest pain and R202Q mutation may be negatively correlated with arthritis, unlike M694V. The genetic results and clinical findings of the patients should be evaluated together and followed up closely. What is Known: • M694V mutation and colchicine resistance were two important risk factors for RI wo AA and amyloidosis in FMF patients. What is New: • Compound heterozygous with M694V mutations were associated with chest pain and may be more serious than thought. • Another point is that while R202Q mutations were negatively correlated with arthritis, M694V mutations were positively correlated.

Colchicine resistance: Associated factors and their effect on health-related quality of life in patients with familial Mediterranean fever

AIM

To determine the factors associated with colchicine resistance and the effect of colchicine resistance on health-related quality of life (QoL) in patients with familial Mediterranean fever (FMF).

METHODS

Demographic and clinical features, MEFV gene mutations, and Pras disease severity scores were recorded. QoL was assessed using the Short Form-36 (SF-36) and FMF-QoL scales. Colchicine resistance was defined as at least 1 attack per month for 6 months at the maximum tolerated dose of colchicine in fully compliant patients.

RESULTS

The mean age of 118 patients (90 female, 28 male) with FMF was 38.4 ± 12.5 years. The percentage of colchicine-resistant patients was 19.5%. In univariable analysis, smoking (odds ratio [OR] = 2.885; 95% confidence interval [CI] = 1.104-7.539; P = 0.031), attack duration (OR = 1.955; 95% CI = 1.137-3.360; P = 0.015), presence of arthritis (OR = 5.235; 95% CI = 1.508-18.179; P = 0.009), and disease severity score (OR = 1.790; 95% CI = 1.334-2.402; P < 0.001) were associated with colchicine resistance. The FMF-QoL and subscales of SF-36 except for role emotional and vitality, were different between colchicine-resistant and non-resistant patients (P < 0.05).

CONCLUSION

Smoking, attack duration, presence of arthritis, and disease severity were associated with colchicine resistance in fully compliant FMF patients. Colchicine-resistant patients had poorer health-related QoL.

Early Predictors of Colchicine Resistance in Familial Mediterranean Fever

OBJECTIVE

To explore early features that can predict colchicine resistance in familial Mediterranean fever (FMF) patients.

METHODS

It included FMF cases who fulfilled the Yalcinkaya-Ozen criterion and were on colchicine for at least 6 months. Data were collected from medical files and interpreted with respect to clinical parameters including, the auto-inflammatory diseases activity index (AIDAI) and FMF severity score. FMF50 score assessed the treatment response. Laboratory findings and genetic analysis of MEFV mutations were evaluated according to the standard technique. Patients were classified into two groups according to their response to colchicine. Both groups were compared and significant variables entered into a logistic regression model to detect independent predictors. The diagnostic accuracy of these predictors was assessed using the receiver operating characteristic (ROC) curve.

RESULTS

120 FMF children were included. After the exclusion of sixteen-non-complaint patients (13.3%), colchicine responders were 66 (63.4%) (group I), and colchicine resistant (group II) were 38 (36.5%). The fever duration after colchicine, number of attacks before/after colchicine, skin rash/erysipelas-like erythema, myalgia/protracted febrile myalgia, AIDIA before/after treatment, FMF severity score, and the maximum colchicine dose were higher in group II. Furthermore, high CRP and neutropenia were frequent in group II. However, different MEFV mutations including, M694V were similar between the two groups. Eight variables were detected in the regression analysis model and independent predictors were utilized to generate a scoring model.

CONCLUSION

: This study constructed a prediction model for colchicine nonresponse based on clinical and laboratory profiles. This model will be valuable for the treatment decisions of FMF children.

The Value of Serum Amyloid A Levels in Familial Mediterranean Fever to Identify Occult Inflammation During Asymptomatic Periods

OBJECTIVE

The aim of this observational study was to evaluate whether there was any correlation between the acute phase reactants in children with familial Mediterranean fever (FMF) during attack and attack-free periods.

METHODS

The study was conducted between June 2016 and January 2018. Clinical features and laboratory parameters of children with FMF during attack and attack-free periods were recorded longitudinally.

RESULTS

The cohort consisted of 168 children with FMF (84 boys, 84 girls). Median values of acute phase reactants during FMF attacks were 433.5 mg/L (34.0-1780.0 mg/L) for serum amyloid A (SAA), 56.7 mg/L (7.6-379.0 mg/L) for C-reactive protein (CRP), and 37.5 mm/h (5-100 mm/h) for erythrocyte sedimentation rate (ESR). Median values for the same tests in attack-free periods were 3.2 mg/L (0.1-25.0 mg/L), 1.7 mg/L (0.1-12.7 mg/L), and 8 mm/h (1-30 mm/h), respectively. Correlation analyses showed that SAA and CRP were highly correlated in FMF attack (r = 0.67, p < 0.01), but no correlation was found between SAA and ESR levels. C-reactive protein was elevated in 13.6%, ESR in 20.8%, and SAA in 28.5% of the patients during attack-free period. Age at onset, sex of the patients, and characteristics of attacks were found to be not associated with elevated SAA in attack-free period. On the other hand, having homozygous exon 10 mutation and having elevated CRP were found to be associated with high SAA in attack-free period.

CONCLUSIONS

C-reactive protein and SAA correlate well with FMF attacks. Therefore, checking for SAA during a FMF attack is not required. However, SAA seems to be the most sensitive method for demonstrating subclinical inflammation in attack-free period. Thus, checking SAA levels might be a valuable tool in selected FMF patients.

Familial Mediterranean fever, from pathogenesis to treatment: a contemporary review

Familial Mediterranean fever (FMF) (OMIM #249100) is the most common hereditary autoinflammatory disease in the world. FMF is caused by gain of function mutations of MEFV gene which encodes an immune regulatory protein, pyrin. Over the last few years, we have witnessed several new developments in the pathogenesis, genetic testing, diagnosis, comorbidities, disease related damage and treatment approaches to FMF. Elucidation of some of the pathogenic mechanisms has led to the discovery of pathways involved in inflammatory, metabolic, cardiovascular and degenerative diseases. The use of next generation sequencing in FMF has revealed many new gene variants whose clinical significance may be clarified by developing functional assays and biomarkers. Clinically, although FMF is considered an episodic disease characterized by brief attacks, recent systematic studies have defined several associated chronic inflammatory conditions. Colchicine is the mainstay of FMF treatment, and interleukin (IL)-1 antagonists are the treatment of choice in refractory or intolerant cases. Experience of IL-1 antagonists, anakinra and canakinumab, is now available in thousands of colchicine resistant or intolerant FMF patients. In this contemporary review, we surveyed current FMF knowledge in the light of these recent advances.

Genotype Mutations in Egyptian Children with Familial Mediterranean Fever: Clinical Profile, and Response to Colchicine

BACKGROUND

Familial Mediterranean fever (FMF) is an autosomal recessive autoinflammatory disorder that is characterized by recurrent episodes of fever, peritonitis, pleuritis, pericarditis, and/or arthritis. MEFV is the responsible gene for FMF, of which more than 310 mutations have been reported; M694V, M694I, V726A, E148Q, and M680I mutations are the five most frequent mutations responsible for the majority of FMF patients in the Middle East.

AIM

To study the genetic background of FMF among Egyptian children to detect the most frequent MEFV mutations and to study the response of colchicine therapy with different gene mutations.

METHODS

This cross-sectional study included 109 pediatric patients already diagnosed clinically with FMF, and were following-up at the Rheumatology Outpatient Clinic, Children's Hospital, Cairo University.

RESULTS

Out of 109 patients, 95 had positive-MEFV mutation (87.16%), of which the most frequent mutations were E148Q (24/95 patients, 25.26%), V726A (19/95 patients, 20%), M680I (19/95 patients, 20%), M694V (17/95 patients, 17.89%), and M694I (7 patients, 7.37%). A better response to colchicine therapy was noted in E148Q mutation; on the other hand, more severe cases were reported with M694V mutations.

CONCLUSION

E148Q, V726A, M680I, M694V and M694I mutations are the most frequent mutations denoting the heterogeneous mutation pattern and the milder form of the disease among Egyptian patients. M694V mutations may indicate a more severe disease score.

Correlation of Secretory Activity of Neutrophils With Genotype in Patients With Familial Mediterranean Fever

OBJECTIVE

Familial Mediterranean fever (FMF) is an autoinflammatory disorder caused by pyrin-encoding MEFV mutations. Patients present with recurrent but self-limiting episodes of acute inflammation and often have persistent subclinical inflammation. The pathophysiology is only partially understood, but neutrophil overactivation is a hallmark of the disease. S100A12 is a neutrophil-derived proinflammatory danger signal that is strongly elevated in active FMF. This study was undertaken to characterize the secretory activity of neutrophils in vitro and investigate the association of S100A12 with disease activity and genotype in patients with FMF.

METHODS

Neutrophils from FMF patients carrying the p.M694V mutation (1 compound heterozygous and 5 homozygous) and neutrophils from 4 healthy control subjects were purified and stimulated in vitro. Neutrophil secretion of S100A12, interleukin-18 (IL-18), IL-1β, and caspase 1 was determined. Based on these in vitro analyses, serum concentrations of S100A12, IL-18, and IL-1β were also analyzed in 128 clinically and genetically characterized patients with FMF.

RESULTS

In vitro, unstimulated neutrophils from p.M694V-positive patients spontaneously secreted more S100A12, IL-18, and caspase 1 compared to neutrophils from healthy controls. Serum concentrations of S100A12 correlated with disease activity and genotype, with the levels being highest in homozygous patients and with compound heterozygotes displaying higher levels than heterozygotes. Compared to individuals negative for the p.M694V mutation, heterozygous, compound heterozygous, or homozygous p.M694V-positive patients had higher serum levels of S100A12 and IL-18 during inactive and subclinical disease.

CONCLUSION

The FMF phenotype is known to be more severe in patients carrying the p.M694V mutation. This report describes 2 molecules secreted by unconventional secretory pathways, S100A12 and IL-18, whose concentrations correlated with clinical disease activity and genotype in patients with FMF. In this clinically and genetically heterogeneous disease, management of these surrogate markers might help to improve patient care and outcomes.

Familial Mediterranean fever-associated diseases in children

BACKGROUND

MEditerranean FeVer (MEFV) gene encodes for the pyrin protein and a mutated pyrin is associated with a prolonged or augmented inflammation. Hence, various diseases were reported to be associated with familial Mediterranean fever (FMF) or carriers of MEFV mutations. However, systematic evaluation of all associated diseases in children with FMF has not been done previously.

AIM

The aim of this study was to investigate the frequency and type of FMF-associated diseases in children.

DESIGN AND METHODS

Files of FMF patients who had been seen in two reference hospitals in Ankara, in the last two years, were retrospectively evaluated. Patients with FMF and concomitant diseases were included to the study.

RESULTS

Among 600 FMF patients, 77 were found to have a concomitant disease (12.8%). Thirty patients (5%) had vasculitis; 21 (3.5%) had juvenile idiopathic artritis (JIA); 7 (1.16%) had inflammatory bowel disease (IBD) and 19 had other diseases including 5 patients with isolated sacroiliitis. Overall, 13 (2.17%) patients had sacroiliitis in our cohort. The most frequent mutation was M694V/M694V (44%) and 81% of the patients had at least one M694V mutation. Majority of the patients (74%) developed associated diseases while they were not receiving colchicine therapy.

CONCLUSIONS

Certain inflammatory diseases including vasculitis, chronic arthritis and IBD were more frequently detected in patients with FMF during childhood. M694V mutation is a susceptibility factor for associated diseases. In countries where FMF is prevalent, clinicians dealing with FMF and other inflammatory diseases should be aware of these associations.

A survey of resistance to colchicine treatment for French patients with familial Mediterranean fever

Background

Colchicine is the standard treatment for familial Mediterranean fever (FMF), preventing attacks and inflammatory complications. True resistance is rare and yet not clearly defined. We evaluated physicians’ definition of colchicine resistance and report how they manage it.

Patients and methods

We recruited patients with a clinical diagnosis of FMF, one exon-10 Mediterranean fever (MEFV) gene mutation and considered resistant to colchicine, via networks of expert physicians. Clinical, biological characteristics and information about colchicine treatment (dose adjustment, compliance) were collected. The severity of FMF was assessed by the Tel Hashomer criteria.

Results

We included 51 patients, most females (55%), mean age 34 ± 23.1 years years (range 4.7–86.3). Overall, 58% (27/47) patients had homozygous M694 MEFV gene mutations. Seventeen of 42 patients (40%) declared full adherence to colchicine treatment, greater for children (48%) than adults (22%). Physicians considered colchicine resistance with > 6 attacks/year (n = 21/51, 42%), > 4 attacks in the last 6 months (n = 13/51, 26%), persistent inflammation (n = 23/51, 45%), renal amyloidosis in (n = 6/28, 22%) of adult patients and intolerance to an increase in colchicine dose (n = 10/51, 19%), and other reasons (n = 13/51, 23%), including chronic arthralgia (n = 6/51, 12%). Interleukin 1–targeting drugs represented the only alternative treatments in addition to daily colchicine.

Conclusion

Resistance to colchicine is rare (<10% of patients) and mostly observed in severe MEFV genotypes. The main reasons for physicians assessing resistance were severe clinical symptoms, persistent subclinical inflammation, and secondary amyloidosis. Low adherence to colchicine treatment is a key component of resistance.

Relationship between clinical findings and genetic mutations in patients with familial Mediterranean fever

BACKGROUND

Familial Mediterranean fever (FMF) is one of the most frequent genetic diseases encountered in the Mediterranean region. We aimed to investigate the correlation between genetic mutations and the clinical findings in 562 patients with FMF.

METHODS

In this retrospective cross-sectional study conducted with patients' files between 2006, and 2013, reverse hybridization assay for MEFV gene mutations was used and the 12 most frequent mutations were screened. Mutation types and clinical findings were compared with variance analysis.

RESULTS

The mean age was 6.9 ± 3.4 years (range, 1.8-11.6 years). The most common symptom was fever (97.3%). Thirty-four of the patients (6.04%) were admitted with periodic fever only. Of these patients, M694V was the most common mutation type (73.5%). The percentage of the patients predominantly presenting with recurrent abdominal pain was 77.78% and the most frequent mutations were M694V and E148Q. The rate of arthritis and arthralgia was significantly higher in patients with M694V and E148Q mutations. Chest pain was reported more often in patients homozygous for M694V (61.4%). Pericardial effusion was documented in the echocardiography of 10.9% of the 229 children with chest pain. Some patients had both FMF and Henoch Schönlein purpura (HSP), and were more likely to harbor either homozygote M694V or E148Q mutations. The frequency of episodes was higher in patients with homozygous M694V mutations (number of attacks = 4.4 ± 1.6/month). Proteinuria was detected in 106 patients of cases (29.2%), at an average of 854 ± 145 mg/L. Most of the patients with proteinuria and elevated serum amyloid-A had homozygous M694V mutation.

CONCLUSION

The most common mutation in children in Turkey with FMF is the M694V mutation. Recurrent abdominal pain, arthritis or arthralgia, chest pain, and pericarditis were commonly seen in patients with M694V and E148Q mutations.

The CYP4502D6 *4 and *6 alleles are the molecular genetic markers for drug response: implications in colchicine non-responder FMF patients

The cytochrome P450 2D6 (CYP2D6) is a cytochrome P450 enzyme involved in the oxidative biotransformation of the xenobiotics, carcinogens and various clinically important drugs. Patients are evaluated in three sub-groups of extensive (EM), intermediate (IM) and poor metabolizer (PM) phenotypes due to their drug-metabolising ability for the target CYP2D6 gene. Colchicine non-responsive FMF patients were prospectively genotyped for the major CYP2D6 alleles in the current study. Major CYP2D6 alleles of *1, *3, *4, *5, and *6 were genotyped for 30 responsive and 60 non-responsive FMF patients by multiplex PCR-based reverse-hybridization StripAssay and real-time PCR methods. DNA banks isolated from blood-EDTA were retrospectively used in the current patients and results were compared statistically. Increased CYP2D6 *4 and *6 allele frequencies were highly detected in the colchicine non-responsive FMF patients when compared to the responsive group. Results showed the frequencies of major CYP2D6 *1(wild), *3(2637A > delA), *4(G1934A), *5(total gene deletion) and *6(1707T del) alleles in 0.550, 0.042, 0.158, 0.025 and 0.225 for non-responder and 0.880 and 0.120 (CYP2D6*1 and *4) for the responder groups, respectively. Despite small sample size, this study suggests that there is an association between CYP2D6*4 and CYP2D6*6 alleles and drug intoxicants in colchicine non-responder FMF patients.