To what extend is nail ultrasound discriminative between psoriasis, psoriatic arthritis and healthy subjects?

To assess the discriminative utility of nail features detected by B-mode (BM) and color Doppler (CD) ultrasound (US) between patients with psoriasis (PsO) and psoriatic arthritis (PsA) and healthy controls. Sixty patients with PsA, 21 patients with PsO, and 20 healthy controls were prospectively included. All patients underwent a dermatologic assessment and PsA patients also a rheumatologic assessment. All patients and controls underwent a US assessment of the finger nails that included a BM score for nail plate integrity and four different CD scores based on the amount and location of CD signals in the nail bed/matrix. In addition, we measured the thickness of the nail bed (TNB) and nail plate (TNP). The BM score and the CD score based on the amount of signals in the nail bed in contact with the ventral plate discriminated between the control group (median, range 0.0, 0-4 and 2.0, 0-9, respectively) and the PsO/PsA group (median, range: 7.0, 0-31 and 5.14, 0-13, respectively) (p < 0.05) with or without clinical nail involvement. The CD scores based on the percentage of the nail bed/matrix occupied by Doppler signals did not discriminate between controls and PsO/PsA patients. TNB and TNP were significantly higher in psoriatic nails with or without clinical involvement than in control nails. In PsO/PsA patients, the BM score, TNB and TNP were significantly higher in clinically involved nail than in clinically non-involved nails. Our results showed discriminative utility of BM US and some CD US features for PsO/PsA nails.

Agreement between semiquantitative and quantitative Doppler scoring systems for the assessment of synovial pathological vascularisation in rheumatoid arthritis.

OBJECTIVES: To compare colour Doppler (CD) versus power Doppler (PD) semiquantitative and quantitative scoring of synovial vascularisation and to evaluate the relationship between semiquantitative and quantitative scores in patients with rheumatoid arthritis (RA). METHODS: One hundred RA patients underwent B-mode, PD, and CD assessments of 12 joints at two European centres. Each joint with synovial hypertrophy (SH) detected on B-mode was semiquantitatively scored (0-3) for PD (SPD score) and CD (SCD score) synovial signal. PD and CD synovial signal were also quantitatively scored (0-100%) (QPD and QCD scores, respectively) using a software integrated in the US equipment for counting the colour fraction. RESULTS: We found SH in 184 joints. SPD and SCD agreed in 92.3% (95%CI: 88.4; 96.2%) of paired scores, with Kendall rank correlation coefficient tau-b=0.95. QPD and QCD scores were highly correlated (Pearson's coefficient=0.70) but Blamd-Altman plot showed insufficient agreement, being the QCD scores systematically slightly higher than the QPD scores. The comparison of mean values of QPD and QCD between scores of SPD and SCD, respectively, showed significant differences between grade 0 and grade 1 (p<0.001), and grade 2 and grade 3 (p=0.042 and p=0.007, respectively) but not between grade 1 and 2 (p=0.154 and p=0.150, respectively). CONCLUSIONS: The SPD and SCD scores were concordant and the QPD and QCD scores highly correlated but were not concordant. There was an overlap between SPD and SCD mild and moderate scores regarding QPD and QCD scores.

An exploratory study to determine whether infliximab modifies levels of rheumatoid factor and antibodies to cyclic citrullinated peptides in rheumatoid arthritis patients.

OBJECTIVES: The aim of this study was to investigate the relationship between serum infliximab (IFX) levels and changes of RF and ACPA levels in patients with rheumatoid arthritis (RA). METHODS: Enzyme-linked immunosorbent assays (ELISA) [Promonitor® IFX R1 (version 2) (Progenika Biopharma, Spain)] were used to measure drug levels and antidrug-antibodies (ADAb) in IFX RA-treated patients (n=19). Disease activity was assessed using DAS28. IgM rheumatoid factor (RF) and IgM, IgA and IgG anti-cyclic citrullinated peptide (ACPA) were determined through ELISA. RESULTS: A significant decrease in RF (p=0.01), ACPA IgG (p=0.007), IgM (p=0.01) and IgA (p=0.03) was observed in patients presenting adequate levels of serum IFX. No significant changes to RF or ACPA were observed in patients with undetectable IFX. CONCLUSIONS: Data from this study support the hypothesis that the anti-TNF antagonist IFX downregulates autoantibody levels in RA patients when IFX levels are detectable. Larger-scale studies need to be performed to establish RF and ACPA presence as therapeutic response predictive factors.

Identifying markers of sustained remission in rheumatoid arthritis patients on long-term tapered biological disease-modifying antirheumatic drugs.

To identify features associated with long-term persistent remission in rheumatoid arthritis (RA) patients on tapered biological disease-modifying antirheumatic drugs (bDMARD) (tap-bDMARD) therapy. We carried out a 40-month (m) extension follow-up study of 77 RA patients from a previous 12 m tap-bDMARD study. Disease activity was assessed at baseline and every 3 months. Doppler US investigation of 42 joints for the presence and grade (0-3) of B-mode synovial hypertrophy (SH) and synovial power Doppler signal (i.e., Doppler synovitis) was performed before starting the tap-bDMARD strategy by a rheumatologist blinded to clinical and laboratory data. At the 40 m mark, 44 (57.1%) patients failed the tap-bDMARD strategy, while 33 (42.9%) succeeded. Patients who presented a failed tap-bDMARD had significantly longer disease duration, a longer time from symptom onset to synthetic (s) DMARD start, longer duration of sDMARD treatment, a greater number of sDMARDs, and a higher baseline DAS28 and SDAI than patients with successful tap-bDMARD at 40 months. In logistic regression analysis, the presence of baseline Doppler synovitis, a DAS28 ≥ 2.2, and the presence of rheumatoid factor were identified as predictors of tap-bDMARD failure at 40 m. In those patients who succeed tap-bDMARD at 12 m, a smoking habit was significantly more frequently found in tap-bDMARD failures at 40 m. Our results showed that DAS28 and the presence of Doppler synovitis, RF and a smoking habit predicted long-term tap-bDMARD failure.

Structural damage in rheumatoid arthritis: comparison between tendon damage evaluated by ultrasound and radiographic damage.

OBJECTIVE: To compare structural damage assessed by conventional radiography and tendon damage assessed by musculoskeletal US (MSUS) at wrist and ankle in RA patients. METHODS: We evaluated 72 consecutive patients [56 (77.8%) females] with RA. The MSUS evaluation consisted in a B-mode examination of bilateral extensor carpi ulnaris and tibialis posterior tendons. Tendon damage was defined and scored according to OMERACT. A total score for the tendon damage score (TDS) was calculated by summing the grades for each tendon. For the radiographic evaluations we used the van der Heijde score; a total radiographic score (RTS) was calculated by summing a bone erosion score (ERS) and a joint space narrowing score (JSNS). RESULTS: We evaluated 288 tendons. The mean (s.d.) of TDS was 2.3 (1.8). Fifty-four (75%) patients presented tendon damage of at least one tendon. From all evaluated tendons, 134 (46.5%) had no tendon damage, 146 (50.7%) had grade 1 and 8 (2.8%) had grade 2 tendon damage. The mean (s.d.) for RTS was 91.4 (97), for ERS was 47.3 (61.9) and for JSNS was 44.1 (37.2). We found a significant correlation between disease duration and both TDS and RTS (r = 0.413 and r = 0.560, respectively; P < 0.0001). We found a good significant correlation between TDS and all variables of radiographic structural damage (RTS, r = 0.65; ERS, r = 0.637; JSNS, r = 0.618; P < 0.001). CONCLUSION: The MSUS assessment of only four tendons can be an additional feasible method to assess structural damage in RA patients.

To what extent is foot pain related to biomechanical changes and ultrasound-detected abnormalities in rheumatoid arthritis?

OBJECTIVES: To investigate the presence of biomechanical abnormalities and ultrasound (US)-detected inflammation and damage in low disease or remission status rheumatoid arthritis (RA) patients with foot complaints. METHODS: We recruited 136 subjects with foot complaints. Sixty-two were biologic disease-modifying antirheumatic drug-treated RA patients presenting Disease Activity Score-determined remission or low disease activity while the remaining 74 were gender matched controls without rheumatic or musculoskeletal disorders. Both groups underwent a comprehensive podiatric, biomechanical and B-mode and Doppler US assessment of the feet. RESULTS: Most RA patients and controls were female (77.4% and 83.8%, respectively). There was no statistical difference in the proportion of obese subjects in either group (p=0.792). Inappropriate shoes were used by 50.0% of RA patients and 33.8% of controls (p=0.080). Talalgia, particularly heel pain, was more frequent in the control group, with associated talalgia and metatarsalgia being more prevalent in the RA group (p<0.05). The RA patient group was also more likely to present greater foot deformity, more limited joint movement and biomechanical abnormalities than the controls (p<0.05). US inflammatory and structural changes were significantly more frequent in RA patients than in controls (p<0.05). US structural involvement was significantly associated with limited joint mobility and pathologic biomechanical tests only in RA patients (p<0.05). CONCLUSIONS: RA foot complaints seemed to be linked to US-detected RA involvement and biomechanical abnormalities. Podiatric and US assessments can be useful to help the clinician to optimise the management of RA patients in remission/low disease activity with foot complaints.

The feet in systemic lupus erythematosus; are we underestimating their involvement and functional impact?

OBJECTIVES: To evaluate biomechanical and ultrasound (US) abnormalities in SLE patients as compared with controls and to assess the relationship between these abnormalities and SLE activity. METHODS: Fifty-four consecutive female patients with SLE with and without foot pain and 60 female controls (30 with foot pain and 30 without foot pain) were recruited. SLE activity was assessed by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). SLE patients and controls blindly underwent a comprehensive podiatric, biomechanical and US evaluation of the feet. US assessment included detection of B-mode synovitis, tenosynovitis, enthesopathy, bone changes and synovial, tenosynovial and entheseal power Doppler (PD) signal. RESULTS: Thirty-one (57.4%) SLE patients had bilateral foot pain and 5 (9.3%) had unilateral foot pain. Metatarsalgia was the most common location for pain but without significant difference between groups (p=0.284). Toe joint deformities were significantly more common in SLE feet as compared with control feet (p<0.0005). SLE feet showed significantly more biomechanical abnormalities than control feet (p<0.05). B-mode synovitis in the tibiotalar joint was strongly associated with having SLE (p<0.0005) and the presence of synovial PD signal in the MTP joints was found only in painful feet of SLE patients. SLEDAI was significantly higher in patients with foot pain than in those with painless feet (p=0.008). However, SLEDAI did not discriminate between patients with and without biomechanical or US abnormalities. CONCLUSIONS: SLE patients showed more biomechanical and US abnormalities in the feet than controls, which were not captured by standardised assessment of the disease activity.

Ultrasound-detected joint inflammation and B cell count: related variables for rituximab-treated RA patients?

This cross-sectional observational study aimed to explore the relationship between B cell count and ultrasound (US)-detected synovitis, in patients with rheumatoid arthritis treated with rituximab. Thirty-seven consecutive RA patients treated with RTX were recruited for the study. The patients underwent clinical [i.e., Disease Activity Score 28 joints (DAS28)], laboratory, and US assessment of 12 joints. Each joint was semiquantitatively (0-3) scored on B-mode and power Doppler mode. The scores were summed, and a global index was created for BM (BMS) and PD scores (PDI) synovitis. BM subclinical synovitis was evident in all patients, with PD synovial signal detected in 16 patients (43.2 %). No correlation was found between DAS28 and US scores. B cells were detected in 27 (72.9 %) patients, but there was no association in the mean B cell count and disease activity as measured by DAS28 (DAS28 < 2.6 = 34.53, DAS28 > 2.6 = 49.45, p = 0.52) and PDI score (PDI < 1 = 49.48, PDI > 1 = 35.44, p = 0.54). There was no correlation between the B cell count and DAS28, BMS, and PDI (r = 0.020, p = 0.907; r = -0.151, p = 0.371; r = -0.099, p = 0.558, respectively). In RTX-treated RA patients, no relationship could be established between US-detected synovitis and peripheral blood B cell count.

Ultrasound-detected activity in rheumatoid arthritis on methotrexate therapy: Which joints and tendons should be assessed to predict unstable remission?

The aim of the study was to investigate the predictive value of different reduced joint ultrasound (US) assessments of synovitis and tenosynovitis in relation to unstable remission in a cohort of rheumatoid arthritis (RA) patients on methotrexate therapy. Forty-seven RA patients (38 women, 9 men), being treated with methotrexate (MTX), in clinical remission as judged by their consultant rheumatologist were evaluated for disease activity according to the Disease Activity Score (DAS) 28 at baseline and 6 months. Sustained remission and unstable remission were defined according to the baseline and 6-month DAS28 and changes in RA therapy during the follow-up. Each patient underwent at baseline a B-mode and power Doppler (PD) assessment of 44 joints and 20 tendons/tendon compartments by a rheumatologist blinded to the clinical and laboratory data. B-mode synovial hypertrophy (SH), synovial PD signal, B-mode tenosynovitis, and Doppler tenosynovitis were scored 0-3. The presence and index of synovial PD signal in 44 joints [odds ratio (OR) 8.21 (p = 0.016) and OR 2.20 (p = 0.049), respectively] and in 12 joints [OR 5.82 (p = 0.041) and OR 4.19 (p = 0.020), respectively], the presence of SH in wrist and MCP joints [OR 4.79 (p = 0.045)], and the presence of synovial PD signal in wrist-MCP-ankle-MTP joints [OR 4.62 (p = 0.046)] were predictors of unstable remission. The 12-joint or wrist-hand-ankle-MTP US assessments can predict unstable remission in RA patients in apparent clinical remission being treated with MTX.

Predictive value of Doppler ultrasound-detected synovitis in relation to failed tapering of biologic therapy in patients with rheumatoid arthritis.

OBJECTIVE: To investigate the predictive value of synovitis detected by Doppler US in relation to failed tapering of biologic therapy (BT) in RA patients in sustained clinical remission. METHODS: A total of 77 RA patients (52 women, 25 men) in sustained clinical remission, treated with a stable dosage of BT were prospectively recruited. BT was tapered according to an agreed strategy implemented in clinical practice (i.e. increasing the interval between doses for s.c. BT and reducing the dose for i.v. BT). BT tapering failure was assessed at 6 and 12 months. Doppler US investigation of 42 joints for the presence and grade (0-3) of B-mode synovial hypertrophy and synovial power Doppler signal (i.e. Doppler synovitis) was performed at baseline by a rheumatologist blinded to clinical and laboratory data. Hand and foot radiographs were obtained at baseline and at 12-month follow-up. RESULTS: Of the 77 patients, 46 (59.7%) were on s.c. BT and 31 (40.3%) on i.v. BT. At 12 months, 35 patients (45.5%) presented BT tapering failure, 23 of them (29.9% of all patients) in the first 6 months of BT tapering. In logistic regression analysis, the baseline DAS28 and the global score of Doppler synovitis were identified as independent predictors of BT tapering failure at 12 and 6 months. The presence of Doppler synovitis was the strongest predictor for BT tapering failure. No patient showed radiographic progression. CONCLUSION: Our results suggest that the presence of Doppler-detected synovitis may predict BT tapering failure in RA patients in sustained clinical remission.

Agreement in assessment of infliximab and adalimumab levels in rheumatoid arthritis: interlaboratory and interassay comparison.

OBJECTIVES: Infliximab (IFX) and adalimumab (ADL) drug levels and anti-drug antibodies (ADA) are assessed using a variety of techniques, therefore, results cannot accurately be compared for clinical purposes. The aim of this study was to test two infliximab (IFX) and adalimumab (ADL) ELISA versions, for drug levels and ADA, to see whether they yield similar results. METHODS: ELISA versions [Promonitor® IFX R1 and R2 (V.1), Promonitor® IFX and Anti-IFX (V.2); Promonitor® ADL R1 and R2 (V.1), Promonitor® ADL and Anti-ADL (V.2) kits (Progenika Biopharma, Spain)] were used to measure drug levels and ADA in IFX (n=24) and ADL (n=24) rheumatoid arthritis-treated patients in three independent laboratories. Quantitative and qualitative agreements were evaluated using intraclass correlation coefficients (ICC), and Cohen's Kappa (κ) respectively. The Bland-Altman plots assessed differences between V.1 and V.2. RESULTS: Interlaboratory agreement (ICC/κ) with V.1 was poor for IFX (0.66/0.62) and ADL (0.69/0.52) drug levels; meanwhile, high agreement was found with V.2 for IFX (0.98/0.95) and ADL (0.094/1.00). Comparison between V.1 and V.2 in each laboratory resulted in systematically higher values in V.2 than in V.1 and poor agreement (ICC/κ ranges) for IFX (0.12-0.7/ 0.19-0.42) and ADL (0.69-0.89 /0.50-0.73). CONCLUSIONS: Qualitative measurements result in better agreement, as evidenced in our study. Greater agreement in V.2 compared with V.1 for IFX and ADL levels could be due to a better tune up. Further studies are required to standardise methods to establish therapeutic reference ranges.

Comparison of two ELISA versions for infliximab serum levels in patients diagnosed with ankylosing spondylitis.

There are various immunosorbent assays which can be used to determine infliximab (IFX) levels. Results vary between assays complicating reliability in everyday clinical practice. The aim of this study was to determine whether quantitative or qualitative assay data prove more accurate in the assessment of infliximab levels in AS patients. We analyzed 40 serum samples, taken prior to infusion, from AS patients who had been undergoing IFX therapy as a first-line of biological treatment for more than a year. IFX levels and IFX-anti-drug antibodies (ADA) were measured using two different ELISA assays [Promonitor IFX R1 and R2 (version 1), Promonitor IFX and anti-IFX (version 2) (Progenika Biopharma, Spain)] strictly following the manufacturer's guidelines. Cohen's unweighted kappa and the intraclass correlation coefficient determined qualitative and quantitative agreement for serum levels in version 1 and version 2. Bland-Altman plots were drawn to compare both assays. The comparison of data measuring IFX levels for version 1 and version 2 resulted in questionable quantitative agreement (ICC 0.659; 95% CI 0.317-0.830) and moderate qualitative agreement (κ 0.607; 95% CI 0.387-0.879) owing to systematically higher values in version 2 than version 1. Version 2 consistently detected higher levels of infliximab, particularly when analyzed in a quantitative context. Further research is needed to synchronize cutoff levels between essays and diseases so therapeutic drug ranges can be established.

Does ultrasound-scored synovitis depend on the pharmacokinetics of subcutaneous anti-TNF agents in patients with rheumatoid arthritis?

OBJECTIVE: The aim of this study was to investigate the influence of the pharmacokinetics of s.c. anti-TNF agents on the grade of US-detected synovitis in RA patients. METHODS: Fifty RA patients were prospectively recruited from the Biologic Therapy Unit of our hospital. Inclusion criteria were being in treatment with s.c. anti-TNF agents and having had neither changes in therapy nor local corticosteroid injections in the previous 3 months. Patients underwent clinical, laboratory [28-joint DAS (DAS28) and Simplified Disease Activity Index (SDAI)] and US assessment at two time points, i.e. at peak plasma drug concentration and at trough plasma drug concentration. US assessments were performed blindly to the anti-TNF agent, the administration time and the clinical and laboratory data. Twenty-eight joints were investigated for the presence and grade (0-3) of B-mode synovitis and synovial power Doppler signal. Global indices for B-mode synovitis (BSI) and Doppler synovitis (DSI) were calculated for 12 joints and for wrist-hand-ankle-foot joints. B-mode US remission was defined as a BSI <1 and Doppler US remission as a DSI <1. RESULTS: There were no significant differences between the clinical, laboratory and B-mode and Doppler US parameters at peak time and trough time (P = 0.132-0.986). There were no significant differences between the proportion of patients with active disease and those in remission according to DAS28, SDAI, B-mode US and Doppler US at peak time and trough time assessments (P = 0.070-1). CONCLUSION: Our results suggested that s.c. anti-TNF pharmacokinetics do not significantly influence US-scored synovitis in RA patients.

Clinical relevance of monitoring serum levels of adalimumab in patients with rheumatoid arthritis in daily practice.

OBJECTIVES: The aim of this paper is to assess the usefulness of measuring serum levels of adalimumab (ADL) and anti-ADL antibodies in 57 patients with rheumatoid arthritis (RA) treated with ADL for at least 3 months in daily practice. METHODS: All patients received concomitant disease-modifying anti-rheumatic drug (DMARD). Receiver-operator characteristics (ROC) analysis was used to obtain the cut-off value of ADL for low disease activity (DAS28-ESR ≤3.2). RESULTS: Anti-ADL antibodies were detected in 4 (7%) patients with a mean (SD) DAS28 score of 4.6 (0.9). Patients with positive anti-ADL antibodies had significantly lower levels of ADL and higher DAS28 scores than those with negative antibodies. Patients with DAS28 ≤3.2 as compared with patients with DAS28 >3.2 showed significantly better SDAI score, higher serum concentrations of ADL and none of them showed anti-ADL antibodies. The cut-off of serum level of ADL for DAS28 <3.2 was 4.3 mg/L. According to serum levels of ADL, patients were grouped into group 1 (low level) <5.5 mg/L, group 2 (medium level) 5.5-11.3 mg/L and group 3 (high level) >11.3 mg/L. Patients in the medium group were closed to clinical remission (median DAS28 2.7) and patients in the high group were on clinical remission (DAS28 2.1). CONCLUSIONS: Serum levels of ADL should be maintained >4.3 mg/L. In patients with ADL levels >11.3 mg/L, a decrease of the dose of ADL or an increase in the interval between doses may be planned. The presence of anti-ADL antibodies was associated with a loss of clinical efficacy of ADL.

Young male patient diagnosed with cutaneous polyarteritis nodosa successfully treated with etanercept.

Cutaneous polyarteritis nodosa (CPAN) is a form of necrotizing vasculitis of small and medium-sized arteries. It is limited to the skin and has a recurrent and chronic course, possibly associated with fever, arthralgia, myalgia and neuropathy, but without visceral involvement. We report the clinical case of a 7-year-old male patient with CPAN refractory to treatment with high doses of corticoids and cyclophosphamide, who was successfully treated with the TNF-α (tumor necrosis factor-alpha) inhibitor, etanercept, in monotherapy.

Patient self-assessment and physician's assessment of rheumatoid arthritis activity: which is more realistic in remission status? A comparison with ultrasonography.

OBJECTIVE: The objective of this study was to compare disease activity assessed by the patient, the physician and musculoskeletal US in patients with RA in clinical remission. METHODS: We evaluated 69 patients with RA in clinical remission according to their attending rheumatologist. Tenderness and swelling in 28 joints were blindly assessed by patients and physicians. The presence of B-mode and Doppler synovitis was blindly investigated in the above joints. The DAS28 and Simplified Disease Activity Index (SDAI) were calculated. RESULTS: The percentage of patients in remission according to the self-derived DAS28 (26.1%) was significantly less than that according to the physician-derived DAS28 (52.2%) (P < 0.0005). There was no significant difference in the percentage of patients in remission according to the self-derived SDAI (14.5%) and the physician-derived SDAI (11.6%) (P = 0.172). We found moderate agreement between the patient-derived and physician-derived DAS28 and SDAI [intraclass correlation coefficient (ICC) = 0.620 and ICC = 0.678, respectively]. Agreement between patient and physician was better for the tender joint count (TJC; ICC = 0.509) than for the swollen joint count (SJC; ICC = 0.279). The mean (S.D.) count for B-mode synovitis [4.09 (3.25)] was significantly greater than the SJC assessed by both the patient and physician [2 (3.71) and 1.42 (2.03), respectively] (P < 0.0005 and P = 0.033, respectively). We found moderate agreement between the physician-assessed SJC and the joint count for Doppler synovitis (ICC = 0.528). CONCLUSION: Patient-assessed and physician-assessed overall RA activity showed acceptable agreement. Patient self-assessment overestimated disease activity determined by the DAS28. At the patient level, physician-assessed joint swelling showed an acceptable concordance with Doppler US synovitis.

Young male patient diagnosed with cutaneous polyarteritis nodosa successfully treated with etanercept.

Cutaneous polyarteritis nodosa (CPAN) is a form of necrotizing vasculitis of small and medium-sized arteries. It is limited to the skin and has a recurrent and chronic course, possibly associated with fever, arthralgia, myalgia and neuropathy, but without visceral involvement. We report the clinical case of a 7-year-old male patient with CPAN refractory to treatment with high doses of corticoids and cyclophosphamide, who was successfully treated with the TNF-α (tumor necrosis factor-alpha) inhibitor, etanercept, in monotherapy.

Total serum immunoglobulin levels in patients with RA after multiple B-cell depletion cycles based on rituximab: relationship with B-cell kinetics.

OBJECTIVE: To investigate whether the incidence of secondary hypogammaglobulinaemia in patients with RA following rituximab was related to patterns of B-cell return and relapse. METHODS: CD19(+) B-cell and serum immunoglobulin (sIg) determinations were done every 2 or 3 months in 137 consecutive patients treated with one or more courses of rituximab-based B-cell depletion therapy. The pattern of B-cell return, either concordant or discordant with relapse, was also recorded. RESULTS: There were 119 responders. Before treatment, three patients had low IgM and four had low IgG. After the first cycle, low IgM or IgG was present in 9.2% (11/119) and 11.8% (14/119) of the patients, respectively, increasing to 38.8% (8/18) and 22.2% (4/18) after five cycles. The mean percent maximum sIg decrease/cycle was relatively constant. The CD19(+) B-cell count at repopulation was not correlated with immunoglobulin (Ig) levels after each cycle. Patients discordant for B-cell return and relapse developed significantly lower serum IgM and more low IgM episodes than concordant patients (P < 0.05). CONCLUSION: Patients with lower baseline sIg levels tended to develop persistent IgM and IgG hypogammaglobulinaemia, resulting from an accumulation of incremental decreases after repeat cycles. This was not due to lower numbers of returning B cells in those developing low sIgs. The association of low IgM in patients with a discordant pattern of relapse suggests that underlying defects in B cells relating to survival and maturation into Ig-secreting cells, as well as attrition of IgG plasma cells may be contributing to low sIg levels in some patients.

Evaluation of 12 GWAS-drawn SNPs as biomarkers of rheumatoid arthritis response to TNF inhibitors. A potential SNP association with response to etanercept.

Research in rheumatoid arthritis (RA) is increasingly focused on the discovery of biomarkers that could enable personalized treatments. The genetic biomarkers associated with the response to TNF inhibitors (TNFi) are among the most studied. They include 12 SNPs exhibiting promising results in the three largest genome-wide association studies (GWAS). However, they still require further validation. With this aim, we assessed their association with response to TNFi in a replication study, and a meta-analysis summarizing all non-redundant data. The replication involved 755 patients with RA that were treated for the first time with a biologic drug, which was either infliximab (n = 397), etanercept (n = 155) or adalimumab (n = 203). Their DNA samples were successfully genotyped with a single-base extension multiplex method. Lamentably, none of the 12 SNPs was associated with response to the TNFi in the replication study (p > 0.05). However, a drug-stratified exploratory analysis revealed a significant association of the NUBPL rs2378945 SNP with a poor response to etanercept (B = -0.50, 95% CI = -0.82, -0.17, p = 0.003). In addition, the meta-analysis reinforced the previous association of three SNPs: rs2378945, rs12142623, and rs4651370. In contrast, five of the remaining SNPs were less associated than before, and the other four SNPs were no longer associated with the response to treatment. In summary, our results highlight the complexity of the pharmacogenetics of TNFi in RA showing that it could involve a drug-specific component and clarifying the status of the 12 GWAS-drawn SNPs.

Facts and controversies in mixed connective tissue disease. / Hechos y controversias en la enfermedad mixta del tejido conectivo.

Mixed connective tissue disease (MCTD) is a systemic autoimmune rheumatic disease (SARD) characterised by the combination of clinical manifestations of systemic lupus erythematosus (SLE), cutaneous systemic sclerosis (SSc) and polymyositis-dermatomyositis, in the presence of elevated titers of anti-U1-RNP antibodies. Main symptoms of the disease are polyarthritis, hand oedema, Raynaud's phenomenon, sclerodactyly, myositis and oesophageal hypomobility. Although widely discussed, most authors today accept MCTD as an independent entity. Others, however, suggest that these patients may belong to subgroups or early stages of certain definite connective diseases, such as SLE or SSc, or are, in fact, SARD overlap syndromes.