Diagnostic Challenges and Solutions in Systemic Amyloidosis.

Amyloidosis refers to a clinically heterogeneous group of disorders characterized by the extracellular deposition of amyloid proteins in various tissues of the body. To date, 42 different amyloid proteins that originate from normal precursor proteins and are associated with distinct clinical forms of amyloidosis have been described. Identification of the amyloid type is essential in clinical practice, since prognosis and treatment regimens both vary according to the particular amyloid disease. However, typing of amyloid protein is often challenging, especially in the two most common forms of amyloidosis, i.e., the immunoglobulin light chain amyloidosis and transthyretin amyloidosis. Diagnostic methodology is based on tissue examinations as well as on noninvasive techniques including serological and imaging studies. Tissue examinations vary depending on the tissue preparation mode, i.e., whether it is fresh-frozen or fixed, and they can be carried out by ample methodologies including immunohistochemistry, immunofluorescence, immunoelectron microscopy, Western blotting, and proteomic analysis. In this review, we summarize current methodological approaches used for the diagnosis of amyloidosis and discusses their utility, advantages, and limitations. Special attention is paid to the simplicity of the procedures and their availability in clinical diagnostic laboratories. Finally, we describe new methods recently developed by our team to overcome limitations existing in the standard assays used in common practice.

Screening for Fabry's disease in a high-risk subpopulation of FMF.

BACKGROUND: Familial Mediterranean fever (FMF) is an autosomal recessive disease associated with mutations in the Mediterranean fever gene (MEFV) that manifests with recurrent episodes of febrile serositis. Fabry's disease (FD) is an X-linked lysosomal storage disease caused by mutations in the alpha-galactosidase A gene and presents with a wide range of gastrointestinal, skin, vascular, renal and neurological manifestations. FMF and FD share similar manifestations, which may lead to misdiagnosis of one as the other; mostly FD is misdiagnosed as FMF. Moreover, various overlapping manifestations may stem from comorbidities, commonly coupled to FMF (such as Behcet's disease, inflammatory bowel disease, glomerulonephritis, fibromyalgia, and multiple sclerosis), as well as from colchicine adverse effects, which may add to the diagnostic confusion. Thus, we postulated that screening FMF for FD will lead to the identification of patients falsely diagnosed with FMF or who, in addition to FMF, suffer from FD that was previously missed. METHODS: To identify missed FD among the FMF population, we performed chemical and genetic analyses for FD in blood samples obtained from a cohort of FMF patients followed in the specialized FMF center of our institution. To increase the likelihood of detecting patients with FD, we enriched the surveyed FMF population with patients exhibiting manifestations shared by patients with FD or who deviate from the typical FMF presentation. RESULTS AND CONCLUSIONS: Of 172 surveyed FMF patients in a cohort derived from a clinic dedicated to FMF, none had FD. Thus, the postulation of increased odds for detecting FD in patients with FMF was not confirmed. Further exploration for FD in FMF population, is nevertheless recommended.

Determining the origin of different variants associated with familial mediterranean fever by machine-learning.

A growing number of familial Mediterranean fever (FMF) patients in Israel do not have a single country of origin for all four grandparents. We aimed to predict the Mediterranean fever gene (MEFV) variant most likely to be found for an individual FMF patient, by a machine learning approach. This study was conducted at the Sheba Medical Center, a referral center for FMF in Israel. All Jewish referrals included in this study carried an FMF associated variant in MEFV as shown by genetic testing performed between 2001 and 2017. We introduced the term 'origin score' to capture the dose and different combinations of the grandparents' origin. A machine learning approach was used to analyze the data. In a total of 1781 referrals included in this study, the p.Met694Val variant was the most common, and the variants p.Glu148Gln and p.Val726Ala second and third most common, respectively. Of 26 countries of origin analyzed, those that increased the likelihood of a referral to carry specific variants were identified in North Africa for p.Met694Val, Europe for p.Val726Ala, and west Asia for p.Glu148Gln. Fourteen of the studied countries did not show a highly probable variant. Based on our results, it is possible to describe an association between modern day origins of the three most common MEFV variant types and a geographical region. A strong geographic association could arise from positive selection of a specific MEFV variant conferring resistance to endemic infectious agents.

The Preferential Use of Anakinra in Various Settings of FMF: A Review Applied to an Updated Treatment-Related Perspective of the Disease.

Familial Mediterranean fever (FMF), the most frequent monogenic autoinflammatory disease, is manifested with recurrent and chronic inflammation and amyloid A (AA) amyloidosis, driven by overproduction of interleukin 1 (IL-1) through an activated pyrin inflammasome. Consequently, non-responsiveness to colchicine, the cornerstone of FMF treatment, is nowadays addressed by IL-1- blockers. Each of the two IL-1 blockers currently used in FMF, anakinra and canakinumab, has its own merits for FMF care. Here we focus on anakinra, a recombinant form of the naturally occurring IL-1 receptor antagonist, and explore the literature by using PubMed regarding the utility of anakinra in certain conditions of FMF. Occasionally we enrich published data with our own experience. To facilitate insights to anakinra role, the paper briefs some clinical, genetic, pathogenetic, and management aspects of FMF. The clinical settings of FMF covered in this review include colchicine resistance, AA amyloidosis, renal transplantation, protracted febrile myalgia, on- demand use, leg pain, arthritis, temporary suspension of colchicine, pediatric patients, and pregnancy and lactation. In many of these instances, either because of safety concerns or a necessity for only transient and short-term use, anakinra, due to its short half-life, is the preferred IL-1 blocker.

Safety of the BNT162b2 mRNA COVID-19 vaccine in patients with familial Mediterranean fever.

OBJECTIVES: Evidence suggests a possible association between the COVID-19 vaccine and autoimmune disease flares or new onset of various autoinflammatory manifestations, such as pericarditis and myocarditis. The objective of this study was to assess the safety of an mRNA-based BNT162b2 anti-COVID-19 vaccine in individuals with FMF, a prototypic autoinflammatory disease. METHODS: Patients participating in this study fulfilled the criteria for diagnosis of FMF, were older than 18 years and received at least one dose of the vaccine. Data on baseline characteristics, features of FMF, post-vaccination side effects, and disease flares were acquired using electronic medical files and telephone interviews. RESULTS: A total of 273 FMF patients were recruited for the study. >95% were vaccinated with two doses of the vaccine. The rates of local reactions following the first and second vaccine doses were 65.5% and 60%, respectively, and 26% and 50.4%, respectively, for systemic adverse events. These rates are lower than those reported for the general population from real-world and clinical trial settings. Postvaccination FMF activity remained stable in most patients. None of the patients reported an attack of pericarditis or myocarditis, considered the most serious vaccine-associated adverse events. Patients with a more active FMF disease and patients harboring the M694V mutation had a significantly higher rate of post-vaccination systemic side effects and attacks. CONCLUSION: The BNT162b2 mRNA COVID-19 vaccine is safe in patients with FMF. Our results support the administration of this vaccine to FMF patients according to guidelines applicable to the general population.

Autonomic Nervous System Indices in Patients with Systemic Sclerosis without Overt Cardiac Disease.

BACKGROUND: Systemic sclerosis (SSc) is a connective tissue disease that may affect the heart and the autonomic nervous system (ANS). There is little knowledge regarding the degree of ANS involvement in SSc patients with unknown cardiac disease. OBJECTIVES: To evaluate cardiac and pupillary autonomic functions in patients before cardiac involvement has emerged. METHODS: The study comprised 19 patients with SSc and 29 healthy controls. Heart rate variability (HRV) analysis for time and frequency domains, as well as deep breathing test and Ewing maneuvers, were performed in all patients. Automated pupillometry for the evaluation of pupillary diameter and pupillary light reflex was completed in 8 SSc patients and 21 controls. RESULTS: Both groups had similar characteristics, except for medications that were more commonly or solely prescribed for SSc patients. Compared with control subjects, the SSc patients had significantly lower HRV parameters of NN50 (15.8 ± 24.4 vs. 33.9 ± 33.1, P = 0.03), pNN50 (4.9 ± 7.4% vs.10.8 ± 10.8%, P = 0.03), and triangular index (11.7 ± 3.4 vs. 15.7 ± 5.8, P = 0.02). Abnormal adaptive responses in heart rate changes were recorded during deep breathing tests and Ewing maneuvers. There was no significant difference in any of the pupillometric indices or other HRV parameters within groups. CONCLUSIONS: SSc patients may manifest cardiac autonomic dysfunction, while their autonomic pupillary function is seemingly spared. The role of certain medications, the significance of differential organ involvement, as well as the prognostic value of our findings should be evaluated in future studies.

Effect of interleukin-1 inhibition in a cohort of patients with colchicine-resistant familial Mediterranean fever treated consecutively with anakinra and canakinumab.

OBJECTIVES: To evaluate the efficacy of IL-1 blockers in a cohort of patients with colchicine-resistant familial Mediterranean fever (crFMF) treated consecutively with anakinra and canakinumab. METHODS: Patients with crFMF treated with anakinra and canakinumab in any order were identified using the computerised database of Sheba Medical Centre. Background characteristics of the patients, reason for switching IL-1 inhibitor, and frequency of attacks under colchicine only, anakinra, and canakinumab were extracted from the computerised patient files. Patients were then interviewed for patient-reported outcomes. RESULTS: A total of 46 patients in our clinic were prescribed canakinumab for crFMF after previous anakinra treatment, whereas no patients who switched treatment from canakinumab to anakinra were identified. Of those, 23/46 patients (50%) discontinued anakinra due to inadequate response (11 of them with secondary failure after a good initial response). Frequency of flares was significantly decreased following switch to canakinumab from anakinra treatment (p<0.01). After the switch to canakinumab, the median duration of flares, the severity of pain during a flare, and the patient's global assessment of disease activity were all significantly decreased (p≤0.01), according to the reports from the patients. CONCLUSIONS: Canakinumab is an effective treatment for FMF after failure of anakinra due to any cause.

Anakinra for colchicine refractory familial Mediterranean fever: a cohort of 44 patients.

OBJECTIVE: FMF is an autoinflammatory disease of genetic origin. Colchicine is the mainstay of treatment for the prevention of attacks and long-term complications but 5-10% of FMF patients are resistant to colchicine therapy. The aim of our study was to investigate the real-life safety and efficacy of anakinra in a cohort of patients with colchicine-resistant FMF. METHODS: In this retrospective study, patients treated with anakinra for colchicine-resistant FMF between 2010 and 2018 were identified using the computerized database of Sheba Medical Center and enrolled in the study. Data from structured clinical files were analysed to evaluate the efficacy and safety outcomes. To assess efficacy, we used the Global Assessment Score (GAS), a measure comprised of three different domains: number of attacks per month, duration of attacks and number of sites involved in the attacks. Reported adverse events were compiled. RESULTS: A total of 44 patients (24 female) were treated with anakinra. Of these patients, 75% were homozygous for the M649V mutation. The mean duration of treatment was 18 months. The GAS decreased significantly from 6.6 (IQR 5.3-7.8) before treatment to 2 (IQR 0-4.2) while on treatment (P < 0.001). During anakinra treatment, six hospitalizations were reported (three due to related adverse effects). In addition, 11 patients suffered from injection site reactions (5 ceased treatment). Twelve patients reported mild side effects. CONCLUSION: Treatment with anakinra is beneficial for the majority of colchicine-resistant FMF patients and is relatively safe.

Familial Mediterranean fever (FMF)-response to TNF-blockers used for treatment of FMF patients with concurrent inflammatory diseases.

OBJECTIVE: Familial Mediterranean fever (FMF) is the most common interleukin 1 (IL-1)-driven monogenic autoinflammatory disease. Yet published data also suggest that tumor necrosis factor (TNF) may have a role in the pathogenesis of FMF and may serve as a target for treatment. In the present study we evaluate this hypothesis. METHODS: To this goal, we studied the incidental effect on FMF of TNF-directed treatment, administered to colchicine-refractory FMF patients for the management of a concurrent inflammatory disease. The rates of FMF patients and of treatments with complete or nearly complete FMF response were determined, based on the number of FMF attacks during TNF-blocker exposures. The possible effect of various FMF and non-FMF features on the outcome was determined using comparative analysis. Patients were identified and data were retrieved using electronic files from the FMF clinic. RESULTS: Twenty-six patients were identified, each receiving ≥1 of four TNF-blockers for a mean duration of 27.6±16.4months. The TNF-blockers were found to induce complete or nearly complete FMF response in 10 (38.5%) of the patients, and in 13 of 50 (26%) exposures. No clinical, genetic, demographic, or therapeutic feature could predict which FMF patient would respond favorably to TNF-blocker therapy. CONCLUSION: This study suggests that TNF-blockers may be beneficial for a small proportion of colchicine-resistant FMF patients.

Amyloid storm: acute kidney injury and massive proteinuria, rapidly progressing to end-stage kidney disease in AA amyloidosis of familial Mediterranean fever.

OBJECTIVE: Amyloid A nephropathy of FMF usually progresses over many years to end-stage renal disease (ESRD). We aim to describe an acute condition, termed here 'amyloid storm', typically manifesting with a rapid (≤2 weeks) increase in serum creatinine and urine protein, that has never been characterized in FMF amyloidosis. METHODS: This retrospective analysis features amyloid storm by comparing between FMF amyloidosis patients who have experienced an episode of amyloid storm (study group) and matched patients who have not (control group). The primary outcome was ESRD or death within 1 year from study entry. Featured data were retrieved from hospital files. RESULTS: The study and control groups, each comprising 20 patients, shared most baseline characteristics. However, they differed on the time from FMF onset to reaching serum creatinine of 1.2 mg/dl [26.5 years (s.d. 15.15) vs 41.55 (10.98), P = 0.001] and the time from the onset of proteinuria to study entry [8.8 years (s.d. 6.83) vs 15.75 (13.05), P = 0.04], culminating in younger age at study entry [39.95 years (s.d. 16.81) vs 48.9 (9.98), respectively, P = 0.05] and suggesting an accelerated progression of kidney disease in the study group. Within 1 year from study entry, 16 patients in the study and 3 in the control groups reached the primary endpoint (P = 0.000). The major triggers of amyloid storm were infections, occurring in 17 of 20 patients. CONCLUSION: Amyloid storm is a complication of FMF amyloidosis, induced by infection and associated with poor prognosis and death.

Repolarization dispersion in patients with systemic sclerosis.

OBJECTIVE: Systemic sclerosis (SSc) is associated with increased cardiac morbidity and mortality. Whether some electrocardiographic markers of arrhythmias predispose to early cardiogenic death in SSc remains controversial. This study evaluated the occurrence of previously reported as well as unstudied markers of repolarization in patients with SSc and assessed their prognostic implications. METHODS: A total of 21 patients with SSc and 31 unaffected controls were included in this prospective study. Electrocardiograms were conducted under strict standards. Repolarization and dispersion parameters and markers of late ventricular potentials were determined using designated computer software. Results of multiple beats were averaged. RESULTS: There were no significant differences between the SSc and control groups in average QT intervals, average corrected QT intervals, average QT interval dispersion (QTd), average QT corrected dispersion (QTcd), and QT dispersion ratio. However, average QT apex dispersion, average JT dispersion, average JT corrected dispersion, and Tpeak-Tend corrected were significantly higher in patients with SSc than in controls. Late ventricular potentials were not found in patients with SSc or in controls. Increased QTd and QTcd were recorded in 1 patient who experienced ventricular arrhythmia before inclusion in the study. None of the remaining patients with SSc or the controls developed arrhythmia during the 9-year follow-up. CONCLUSION: Abnormal repolarization parameters may be observed in patients with SSc. However, their prognostic significance with regard to increased risk for repolarization-associated ventricular arrhythmias and increased cardiac death could not be determined in this study. Our findings endorse additional studies on this matter.

Burden of illness in hereditary periodic fevers: a multinational observational patient diary study.

OBJECTIVES: This study aimed to characterise the burden of illness of patients with inadequately controlled hereditary periodic fevers (HPFs), during and outside of flares. It was focused on the burden to the patients and also considered the wider impact on their caregivers and families. METHODS: The target population was patients or caregivers of patients with clinically/genetically confirmed colchicine resistant FMF (crFMF), mevalonate kinase deficiency/hyperimmunoglobinaemia D with periodic fever syndrome (MKD/HIDS) or TRAPS, who were expected to flare at least once in a 6-month period based on patient history. Disease burden was captured during and between flares using an electronic diary (e-diary) with questions on patient functioning, emotional/social well-being and pain, using validated instruments. RESULTS: HPF-related symptoms such as fever, joint, muscle or bone pain and tiredness and fatigue were reported by patients both during and outside of a flare. The SF-10 Health Survey (SF-10v2) (paediatric patients) and SF-12 Health Survey (SF-12v2) (adult patients) showed that flares negatively impacted patients' psychosocial and physical health. Negative effect of on-flare status on health utility index score assessed by the Short-Form Six-Dimension (SF-6D) was significant only for crFMF patients. Furthermore, the Sheehan Disability Score (SDSv3) showing the on-flare status resulted in significant functional impairment in all 3 disease cohorts through assessment of impact on work/school, social and family life. CONCLUSIONS: crFMF, MKD/HIDS and TRAPS negatively affected the quality of life (QoL) of adult and paediatric patients, including their physical, mental, psychosocial health, and social functioning. There remains, however, a high number of unmet needs for these patients to reduce their disease burden.

Evaluation of a Proarrhythmic Repolarization Marker (Total Cosine R to T) in Patients With Uncomplicated Familial Mediterranean Fever.

Familial Mediterranean fever (FMF) is a systemic autoinflammatory disorder characterized by recurrent attacks of fever and serous inflammation. The association between FMF and risk of cardiac arrhythmia is continuously questioned; some studies report abnormal cardiac repolarization, while others do not. Considering this controversy, we aim to perform in a large cohort of FMF patients a total cosine R to T (TCRT) analysis, a previously unexplored repolarization marker in this disorder. METHODS: The study group included 56 FMF patients without amyloidosis, diagnosed with FMF according to published criteria and 131 control subjects, unaffected with FMF. A 12-lead electrocardiogram (ECG) was performed according to strict standards. Electrocardiogram files were processed with Python-based computer software. Patients were followed for 10 to 12 years, and the rate of cardiac complications was evaluated. RESULTS: Other than FMF and prescription of colchicine, both groups had similar medical and demographic background. TCRT results were similar for a randomly selected beat (0.40 ± 0.06 vs 0.50 ± 0.04, p > 0.05) and for an averaged beat (0.39 ± 0.06 vs 0.50 ± 0.04, p > 0.05) in FMF patients and control subjects, respectively. Correction of average TCRT for heart rate also resulted in similar TCRTc values in patients and control groups (0.42 ± 0.07 s vs 0.51 ± 0.05 s, respectively, p > 0.05). During the follow-up period, none of the patients died, and no patient developed clinical symptoms suggestive of ventricular arrhythmias. CONCLUSIONS: Colchicine treated uncomplicated FMF patients have normal TCRT and TCRTc values, implying low risk for cardiac arrhythmias in this population. Future studies should evaluate the sensitivity and specificity of this marker in high-risk FMF populations, such as those who developed AA amyloidosis.

Saliva immunoglobulin free light chain analysis for monitoring disease activity and response to treatment in multiple sclerosis.

BACKGROUND: Immunoglobulin free light chains (FLC) have recently gained considerable interest as new promising intrathecal biomarkers of multiple sclerosis (MS). However, lumbar puncture is invasive and not practical for monitoring disease course. This study aimed to assess the utility of saliva FLC as a biomarker of disease activity and response to treatment in MS METHODS: Western blotting was used to study saliva FLC monomers and dimers. The intensity of immunoreactive FLC bands was quantified by electrophoresis analysis, and the obtained values were used as FLC indices to account for kappa and lambda FLC monomer and dimer levels. Firth's logistic regression analysis suitable to study small cohorts was applied to compare FLC levels between M.S. patients in relapse, MS patients in remission, and healthy controls. Association between FLC levels and clinical and radiological parameters was analyzed. RESULTS: 55 MS patients and 40 healthy controls were evaluated. Saliva FLC levels were significantly higher in relapse compared to remission. Logistic regression analysis employing a combination of FLC indices confirmed the significant difference between these two groups. The FLC levels were significantly reduced by treatment with corticosteroids. During remission, patients treated with disease-modifying therapies had lower levels of FLC compared to untreated patients. The increased FLC levels were associated with the presence of gadolinium-enhancing lesions, but not with MRI T2 lesion load and EDSS scores. During individual patient follow-up, the changes of the saliva FLC levels were in concordance with the disease activity status. CONCLUSIONS: Saliva FLC levels may be a useful biomarker for discriminating between stable remission and active disease. The developed test may serve as a new, non-invasive, and inexpensive tool for monitoring disease activity and response to treatment in MS.

QT variability index in patients with systemic sclerosis.

OBJECTIVE: Systemic sclerosis (SSc) may affect the heart with microvascular dysfunction and lead to an early cardiac death, but the association between certain repolarization indexes and SSc heart disease remains controversial. Our goal was to evaluate a previously unstudied marker of repolarization dynamics, i.e., QT variability, in patients with SSc and to assess its prognostic implications. METHODS: A total of 17 patients with SSc and 21 healthy controls were included into this prospective study. Electrocardiograms were conducted under strict standards. The QT variability index (QTVI), normalized QT variability (QTVN), and power spectral analysis of QT dynamics, considered as markers of ventricular arrhythmias in a number of other disorders, were determined using designated computer software. RESULTS: There was no significant difference in demographic and cardiac important clinical parameters between the groups. Also, the mean QTVI, QTVN, and power spectral analysis parameters were comparable between the patients with SSc and control subjects. At baseline, the QTVI values of 1 patient with SSc, who experienced ventricular arrhythmia prior to inclusion in the study, were considerably higher compared to other patients with SSc. None of the remaining patients with SSc or the control subjects developed arrhythmia during the follow-up of 8 years. CONCLUSION: Higher than normal QTVI may be found in the minority of patients with SSc. The prognostic significance of this finding is unknown, but it may entail an increased risk of ventricular arrhythmias. Therefore, the value of QTVI as a tool for arrhythmia risk stratification in SSc merits further research.

[IS THERE A CORRELATION BETWEEN CARRIAGE OF AN MEFV MUTATION AND GOUT?]

INTRODUCTION: Gout is an inflammatory condition mediated by Interleukin-1-beta (IL-1ß). A mutation in the MEFV gene (the gene related to Familial Mediterranian fever) may cause an elevation in IL-1ß, and is associated with a variety of inflammatory conditions. Reports in the literature are inconsistent as to whether a mutated MEFV gene is related to the phenotype of gout. OBJECTIVES: To assess whether a carriage state of a mutation in the MEFV gene correlates with the expression and severity of gout. METHODS: A total of 73 patients, 50 with gout and 23 with hyperuricemia were examined for an MEFV mutation. Carriage rate was compared between hyperuricemic and gout patients, and disease activity measures were compared between MEFV mutation carriers and non-carriers. RESULTS: We did not find a statistically significant difference in the carriage rate of an MEFV mutation between gout patients and hyperuricemic patients without gout, nor did we find a correlation between MEFV mutation carriage and gout severity. CONCLUSIONS: Further large-scale studies should be conducted in order to determine a possible correlation between MEFV mutation carriage and gout.

Classification criteria for autoinflammatory recurrent fevers.

BACKGROUND: Different diagnostic and classification criteria are available for hereditary recurrent fevers (HRF)-familial Mediterranean fever (FMF), tumour necrosis factor receptor-associated periodic fever syndrome (TRAPS), mevalonate kinase deficiency (MKD) and cryopyrin-associated periodic syndromes (CAPS)-and for the non-hereditary, periodic fever, aphthosis, pharyngitis and adenitis (PFAPA). We aimed to develop and validate new evidence-based classification criteria for HRF/PFAPA. METHODS: Step 1: selection of clinical, laboratory and genetic candidate variables; step 2: classification of 360 random patients from the Eurofever Registry by a panel of 25 clinicians and 8 geneticists blinded to patients' diagnosis (consensus ≥80%); step 3: statistical analysis for the selection of the best candidate classification criteria; step 4: nominal group technique consensus conference with 33 panellists for the discussion and selection of the final classification criteria; step 5: cross-sectional validation of the novel criteria. RESULTS: The panellists achieved consensus to classify 281 of 360 (78%) patients (32 CAPS, 36 FMF, 56 MKD, 37 PFAPA, 39 TRAPS, 81 undefined recurrent fever). Consensus was reached for two sets of criteria for each HRF, one including genetic and clinical variables, the other with clinical variables only, plus new criteria for PFAPA. The four HRF criteria demonstrated sensitivity of 0.94-1 and specificity of 0.95-1; for PFAPA, criteria sensitivity and specificity were 0.97 and 0.93, respectively. Validation of these criteria in an independent data set of 1018 patients shows a high accuracy (from 0.81 to 0.98). CONCLUSION: Eurofever proposes a novel set of validated classification criteria for HRF and PFAPA with high sensitivity and specificity.

Kidney disease and plasma cell dyscrasias: ambiguous cases solved by serum free light chain dimerization analysis.

BACKGROUND: Plasma cell dyscrasias (PCD) comprise a wide spectrum of disorders, which may adversely affect the kidney. However, in some PCD cases associated with kidney disease, the routine laboratory tests may be incapable to determine precisely the form of PCD, i.e., benign or malignant. Moreover, the kidney biopsy needed for precise diagnosis may be risky or declined. To overcome these limitations, we have developed and reported a new non-invasive technique based on serum free light chains (FLC) monomer (M) and dimer (D) pattern analysis (FLC MDPA), which allowed differentiation between malignant and benign PCD forms. The objective of our retrospective study was to demonstrate the utility of FLC MDPA in solving ten puzzling PCD cases complicated with kidney disease (patients 1-10). METHODS: Ten patients with uncertain form of PCD or with a questionable response to treatment were studied. In addition to routine laboratory tests and clinical evaluation of the PCD patients, our previously developed FLC MDPA in sera and biochemical amyloid typing in biopsy tissues were applied. RESULTS: The FLC MDPA aided the diagnosis of the PCD underlying or accompanying the kidney disease in patients 1-5, and helped to interpret properly the response to treatment in patients 1, 6-10. The FLC MDPA findings were confirmed by a biochemical analysis of tissue amyloid deposits and subsequently by the outcome of these patients. CONCLUSIONS: FLC MDPA is a non-invasive diagnostic test useful in the management of ambiguous cases of PCD associated with kidney disease.

Efficacy and safety of long-term treatment with intravenous colchicine for familial Mediterranean fever (FMF) refractory to oral colchicine.

Colchicine is the mainstay of treatment for familial Mediterranean fever (FMF). Intravenous (IV) colchicine, administered over several months, has been shown to be effective for FMF patients unresponsive to oral colchicine. The objective of this study was to evaluate the efficacy and safety of long-term IV colchicine treatment in oral colchicine-resistant FMF. We analyzed data of 15 patients with frequent FMF attacks, despite a maximal tolerated dose of oral colchicine (2-3 mg/day), who were treated with weekly IV injections of 1 mg of colchicine for at least 12 months. Treatment efficacy was determined by changes in frequency, duration and severity of FMF attacks. Safety was assessed according to adverse events. The mean duration of IV colchicine treatment was 5.16 ± 2.85 years. Decreases were observed from pre-treatment period in the monthly mean rates of abdominal attacks (from 5.6 ± 3.7 to 1.9 ± 3.3, p = 0.0009), joint attacks (from 6.5 ± 5.1 to 1.6 ± 1.6, p = 0.01) and overall attacks (from 22.3 ± 16.2 to 7.4 ± 5.7, p = 0.002) as well as in the mean duration (from 3.8 ± 1.5 to 2.4 ± 1.1 days per attack, p = 0.008) and severity of attacks (from 9.9 ± 0.3 to 5.7 ± 2.6, on a scale of 0-10, p < 0.05). The rate of adverse events was low, and they were mainly gastrointestinal. No severe or serious adverse events were recorded. Long-term treatment with IV colchicine in patients unresponsive to oral colchicine therapy is effective and safe.