Successful long-term systemic sclerosis treatment by high-frequent low-dose B cell-depleting therapy.

OBJECTIVES: Systemic sclerosis (SSc) is a multiorgan disease with a 10-year mortality rate of up to 50 %. B cell-depleting therapy with rituximab (RTX) appears effective in SSc treatment, but data from randomized controlled trials (RCTs) are lacking, and the frequency and dosage of RTX in SSc have no consensus. We aimed to evaluate the long-term efficacy and safety of quarterly RTX administration in SSc. METHODS: This study retrospectively analyzed 40 patients with SSC treated with RTX twice within 14 days every 3 months from 2010 to 2020. The patients fulfilled the LeRoy and the American College of Rheumatology/European League Against Rheumatism Criteria for SSc. Modified Rodnan skin score (mRSS), lung function test results, and serum immunoglobulin (IgG, IgA, and IgM) concentrations were analyzed. RESULTS: A total of 40 patients with SSc received RTX over a median time of 3.9 years (range: 1-10 years). The median mRSS (baseline: 19, 24 months: 16, p < 0.001) demonstrated a significant improvement, and the predicted forced vital capacity was stable. No new or unexpected safety signals, especially regarding treatment-related infectious adverse events, were observed. Immunoglobulin concentrations were within normal range, and specific antibodies to pneumococcal polysaccharides were preserved despite long-term B cell-depleting therapy. None of the patients died during the observation period of up to 10 years. CONCLUSION: SSc was effectively and safely treated with low-dose RTX quarterly. RCTs are warranted to validate the advantage of continuous B cell depletion by quarterly low-dose RTX administration compared to other treatment intervals.

RADAI-5 to monitor rheumatoid arthritis.

Providing the physician with sufficient information about the disease course can be regarded as the most important requirement for any disease assessment tool besides easy applicability and time-sparing documentation. Applying the RADAI-5 in daily routine provides the patient's view at any time completing the questionnaire. In a first study, the RADAI-5 resulted to be highly significantly correlated to the RADAI, and all composite indexes. Changes of the RADAI-5, the DAS28-ESR, and the CDAI were significantly correlated, indicating the instrument's sensitivity to change. A second study including 392 RA patients led to the establishment of thresholds for disease activity categories according to the RADAI-5, as follows: 0.0 up to 1.4 for a remission-like state, 1.6 up to 3.0 for mild disease activity, 3.2 up to 5.4 for moderate and from 5.6 up to 10.0 for high disease activity. In a third study, remission according to the RADAI-5 appeared to be highly specific for the ACR/EULAR criteria for remission The RADAI-5 questionnaire constitutes an easily applicable tool for routine RA monitoring, providing physicians with reliable information about the disease course and sensitivity enough to sound the alarm should complications occur.

Superior specificity of anti-citrullinated peptide antibodies in patients with chronic lymphocytic leukemia and arthritis.

OBJECTIVES: Sera from patients with lymphoid neoplasias contain rheumatoid factors (RF) so often that RF are of limited use for diagnosing arthritis in lymphoma patients. Antibodies against citrullinated peptides (ACPA) might be helpful in distinguishing between true RA and rheumatoid factor-positive conditions with arthritis. We compared the specificity of RF and of ACPA for the diagnosis of RA in patients with B-cell chronic lymphocytic leukemia (CLL). METHODS: One hundred and seven patients with CLL without any clinical signs of arthritis and five patients with RA and concomitant CLL were included in the investigation. Serum samples were tested for RF-isotypes IgM, IgG and IgA. ACPA were determined with an ELISA that detects anti-cyclic citrullinated peptide (aCCP) antibodies. RESULTS: RF well beyond the cut-off levels were detected in 50% of the CLL patients without RA. The isotype distribution was 41% IgM-RF, 20% IgG-RF and 3% IgA-RF. None of the 107 CLL patients without arthritis had Accp antibodies. Within the whole cohort of CLL patients the specificity for the diagnosis of RA was 100% for aCCP antibodies and 59% for IgM-RF. CONCLUSIONS: Only aCCP antibodies but not IgM-, IgG- or IgA-RF are useful for the diagnosis of RA in patients with CLL.

Efficacy and safety of certolizumab pegol monotherapy every 4 weeks in patients with rheumatoid arthritis failing previous disease-modifying antirheumatic therapy: the FAST4WARD study.

BACKGROUND: Tumour necrosis factor alpha (TNFalpha) is a proinflammatory cytokine involved in the pathogenesis of rheumatoid arthritis (RA). Treatment with TNFalpha inhibitors reduces disease activity and improves outcomes for patients with RA. This study evaluated the efficacy and safety of certolizumab pegol 400 mg, a novel, poly-(ethylene glycol) (PEG)ylated, Fc-free TNFalpha inhibitor, as monotherapy in patients with active RA. METHODS: In this 24-week, multicentre, randomised, double-blind, placebo-controlled study, 220 patients previously failing > or =1 disease-modifying antirheumatic drug (DMARD) were randomised 1:1 to receive subcutaneous certolizumab pegol 400 mg (n = 111) or placebo (n = 109) every 4 weeks. The primary endpoint was 20% improvement according to the American College of Rheumatology criteria (ACR20) at week 24. Secondary endpoints included ACR50/70 response, ACR component scores, 28-joint Disease Activity Score Erythrocyte Sedimentation Rate 3 (DAS28(ESR)3), patient-reported outcomes (including physical function, health-related quality of life (HRQoL), pain and fatigue) and safety. RESULTS: At week 24, the ACR20 response rates were 45.5% for certolizumab pegol 400 mg every 4 weeks vs 9.3% for placebo (p<0.001). Differences for certolizumab pegol vs placebo in the ACR20 response were statistically significant as early as week 1 through to week 24 (p<0.001). Significant improvements in ACR50, ACR components, DAS28(ESR)3 and all patient-reported outcomes were also observed early with certolizumab pegol and were sustained throughout the study. Most adverse events were mild or moderate and no deaths or cases of tuberculosis were reported. CONCLUSIONS: Treatment with certolizumab pegol 400 mg monotherapy every 4 weeks effectively reduced the signs and symptoms of active RA in patients previously failing > or =1 DMARD compared with placebo, and demonstrated an acceptable safety profile. TRIAL REGISTRATION NUMBER: NCT00548834.

[Mechanisms of muscle pain : significance of trigger points and tender points]. / Mechanismen des Muskelschmerzes : Bedeutung von Trigger points und Tender points.

Fibromyalgia syndrome (FMS) and myofascial pain syndrome (MPS) belong to the group of chronic non-inflammatory pain syndromes affecting muscles and tendinous insertions. Important criteria in the diagnosis of both diseases are the presence of "tender points" and "trigger points". According to ACR criteria FMS is characterized by the presence of tender points whereas trigger points are typically found in MPS.The main difference is that until now tender points could only be defined in terms of their localization, whereas trigger points can be found upon palpation which may cause a specific referred pain pattern. In addition, analysis of trigger points by microdialysis demonstrated elevated levels of pro-inflammatory substances at these sites. Moreover, local treatment of trigger points either by manipulative therapy or injection appears to be most effective for prompt relief of symptoms.

Blockade of tumour necrosis factor {alpha} significantly alters the serum level of IgG- and IgA-rheumatoid factor in patients with rheumatoid arthritis.

OBJECTIVE: To determine the effect on the humoral immune system of long term treatment of patients with RA with etanercept. METHODS: 12 consecutive patients with seropositive RA treated with etanercept were studied and followed up for 9 months. Clinical efficacy of treatment was evaluated using the 28 joint count Disease Activity Score (DAS28). Serum samples were collected at baseline and after 9 months and serum immunoglobulin, RF isotypes, and anti-cyclic citrullinated peptide (aCCP), antinuclear, nucleosome, and dsDNA antibodies determined. For comparison 7 patients with seropositive RA treated with adalimumab were studied. RESULTS: DAS28 decreased significantly after the first month and then was constant for the whole study (5.7 (0.3) v 3.8 (0.2), p< or=0.000). Serum IgA-RF and IgG-RF increased significantly after 9 months' etanercept treatment (mean (SEM) IgA-RF rose from 19.5 (4.8) to 30.5 (5.9) IU/ml, p< or=0.01; IgG-RF from 20.6 (8.1) to 33.8 (11.5) IU/ml, p< or=0.04). Serum levels of total immunoglobulin and specific autoantibodies remained unchanged during the study. In patients treated with adalimumab, no significant changes in serum levels of RF isotypes and aCCP antibodies were seen. CONCLUSION: Etanercept, although effective in treating the clinical symptoms of RA, seems to have a pivotal effect on RF-producing B cells either directly or indirectly.

The role of CD40-CD40 ligand (CD154) interactions in immunoglobulin light chain repertoire generation and somatic mutation.

To determine whether CD40 ligation influences the molecular and selective mechanisms that govern the development of the human Ig light chain repertoire, analysis of the Vkappa and Vlambda repertoires of CD19+ B cells obtained from a patient with X-linked hyper IgM syndrome (XHIM) and a nonfunctional CD154 was carried out. The nonproductive Vkappa and Vlambda repertoires were largely comparable to that of the normals with respect to V gene and J segment distribution as well as CDR3 length and VLJL joint complexity. Comparison of the nonproductive and productive repertoires indicated that a limited number of VL genes were positively and negatively selected in the XHIM patient. Although mutations were observed in the XHIM VL repertoires, the frequency of mutations was significantly lower than in normals. Typical targeting of these mutations into RGYW/WRCY motifs was significantly reduced and subsequent selection of RGYW/WRCY mutations, which is normally observed, was not found. These results indicate that CD40 ligation is not required for generation of the light chain repertoire, positive selection of some Vk rearrangements, negative selection of specific VL genes, and some degree of somatic mutation. Importantly, however, targeting of mutations to RGYW/WRCY motifs and subsequent selection of these mutated motifs does not occur in the absence of CD40 ligation.

The influence of CD40-CD154 interactions on the expressed human V(H) repertoire: analysis of V(H) genes expressed by individual B cells of a patient with X-linked hyper-IgM syndrome.

Analysis of the V(H)DJ(H) repertoire of peripheral blood IgM(+) B cells from a patient with X-linked hyper-IgM syndrome (X-HIgM) was undertaken to determine whether the distribution of V(H) families in the productive repertoire might be regulated by in vivo CD40-CD154 interactions. The distribution of V(H) genes in the non-productive repertoire of IgM(+) B cells was comparable in X-HIgM and normals. Unlike the normal productive V(H) repertoire, however, in the X-HIgM patient the V(H)4 family was found at almost the same frequency as the V(H)3 family. This reflected a diminution in the positive selection of the V(H)3 family observed in normals and the imposition of positive selection of the V(H)4 family in the X-HIgM patient. Unique among the V(H)3 genes, V(H)3-23/DP-47 was positively selected in both normals and the X-HIgM patient. No major differences in the usage of J(H) or D segments or the complementarity-determining region (CDR) 3 were noted, although the foreshortening of the CDR3 noted in the mutated V(H) rearrangements of normals was absent in the X-HIgM patient. Finally, a minor degree of somatic hypermutation was noted in the X-HIgM patient. These results have suggested that specific influences on the composition of the V(H) repertoire in normals require CD40-CD154 interactions.

Similar characteristics of the CDR3 of V(H)1-69/DP-10 rearrangements in normal human peripheral blood and chronic lymphocytic leukaemia B cells.

The variable heavy chain (V(H)) gene segment V(H)1-69/DP-10 has been shown to be over-represented in B-cell chronic lymphocytic leukaemia (CLL). Because of certain similar characteristics of their complementarity determining region 3 (CDR3), including preferential utilization of J(H)6 elements and an extended length, it has been suggested that antigenic stimulation might be involved in leukaemogenesis. Utilizing single-cell PCR to amplify and sequence genomic DNA from individual normal human peripheral blood B cells, we have obtained 7/421 productively and 1/69 nonproductively rearranged V(H) genes that used V(H)1-69/DP-10. All productive rearrangements were unmutated, used J(H)6 and had an average CDR3 length similar to that previously found in V(H)1-69/DP-10-expressing CLL cells. These results suggest that CLL may arise from B cells commonly found in the peripheral B-cell repertoire and do not represent expansion of a unique subset of specific antigen-reactive B cells.

Analysis of the targeting of the hypermutational machinery and the impact of subsequent selection on the distribution of nucleotide changes in human VHDJH rearrangements.

B cells are unique in that they generate and tolerate a high rate of mutations in their antigen receptor genes and employ these mutations as a basis of avidity maturation. The precise role of the mutational machinery versus subsequent selection in determining the frequency and distribution of mutations has not been fully analyzed. To address these issues, the influence of the intrinsic mutational machinery and subsequent selection on the frequency and distribution of mutations in the expressed human immunoglobulin repertoire was analyzed. Analysis of non-productively rearranged VH genes from individual human B cells provided an opportunity to examine the immediate impact of somatic hypermutation without superimposed selective influences. Comparison with the frequency and distribution of mutations in the productively rearranged human VH genes permitted an estimate of the influences of subsequent selection.

Pairing of variable heavy and variable kappa chains in individual naive and memory B cells.

A functional Ig consists of two heterodimers each of which is composed of a heavy and a light chain. Although there is increasing knowledge about the events that govern the rearrangement of the genes encoding each individual chain, only very limited information is available about the mechanisms governing the pairing of variable heavy (V(H)) and variable light (V(L)) chains. Using a single cell PCR, we were able to obtain V(H) and Vkappa chains from 144 individual human CD19+/IgM+ B cells. Pairing of specific V(H) or Vkappa families was not observed, nor was the length or the amino acid composition of the CDR3s of V(H) and Vkappa chains in individual B cells similar. Comparison of V(H) and Vkappa genes in B cells in which one or both contained evidence of somatic hypermutation with those with no mutations revealed a significant decrease in the mean length of the V(H) CDR3. Moreover, there was a significant correlation between the frequencies of mutations in V(H) and Vkappa gene pairs in individual B cells. These results indicate that Ag-mediated selection as opposed to V(H)DJ(H) recombination or subsequent Ig chain pairing tended to approximate the CDR3 lengths and the frequency of mutations of V(H) and Vkappa in individual B cells.

Comparable impact of mutational and selective influences in shaping the expressed repertoire of peripheral IgM+/CD5- and IgM+/CD5+ B cells.

Somatic hypermutation and subsequent selection play a significant role in shaping the peripheral B cell repertoire. This repertoire is composed of CD5+ (5%) and CD5- B cells (95%) which are known to traffic through different lymphoid compartments. Previous studies have shown that V(H) gene usage by CD5+ and CD5- B cells is similar, although mutations are more frequent in the latter. However, the effect of mutation and subsequent selection on the expressed V(H) repertoire of CD5+ and CD5- B cells has not been delineated in detail. This study, therefore, analyzed the mutational pattern of individual IgM+/CD5+ and IgM+/CD5- B cells. In both populations, mutations can occur without heavy chain isotype switching. Despite the differences in mutational frequency, the patterns of mutation and subsequent selection were comparable in CD5+ and CD5- B cells. These results imply that although mutations are more frequent in CD5- B cells, the overall mechanisms governing somatic hypermutation and subsequent positive and negative selection are similar in CD5+ and CD5- B cells.

Delineation of selective influences shaping the mutated expressed human Ig heavy chain repertoire.

After Ag exposure, somatic hypermutation and subsequent selection play significant roles in shaping the peripheral B cell repertoire. However, the disparate impact of each process has not been completely delineated. To address this, the mutational patterns of a large panel of productive V(H)DJ(H) rearrangements of individual human B cells were analyzed and compared with those of a previously reported panel of nonproductive V(H)DJ(H) rearrangements. The productive V(H) rearrangements exhibited a significantly lower mutational frequency and a significantly smaller number of replacement mutations than the nonproductively rearranged genes, suggesting that structural constraints of the Ig molecule and selective influences both impacted the repertoire, militating against replacement mutations. Positive selection favored a mean of four to six replacements in complementarity-determining region 1 (CDR1) and CDR2, and less than two replacements in the framework regions (FRs). In contrast, the negative impact of replacement mutations generated an increased number of silent mutations within both the CDRs and FRs of the productive repertoire accompanied by a net increase in the ratio of replacement to silent mutations in the CDRs compared with that in the FRs. Moreover, there was a negative influence on the distribution of amino acid changes resulting from mutations of highly mutable codons, such as AGY, TAY, GTA, and GCT, preferentially leading to conservative changes in the expressed Ig repertoire. The results are consistent with the conclusion that the expressed repertoire is limited, compared with the potential generated by the mutational machinery, by the dual requirements of avoiding autoreactivity and satisfying structural constraints of an intact Ig molecule.

Analysis of the human VH gene repertoire. Differential effects of selection and somatic hypermutation on human peripheral CD5(+)/IgM+ and CD5(-)/IgM+ B cells.

To analyze the immunoglobulin repertoire of human IgM+ B cells and the CD5(+) and CD5(-) subsets, individual CD19(+)/ IgM+/CD5(+) or CD5(-) B cells were sorted and non-productive as well as productive VH gene rearrangements were amplified from genomic DNA and sequenced. In both subsets, the VH3 family was overrepresented largely as a result of preferential usage of a small number of specific individual family members. In the CD5(+) B cell subset, all other VH families were found at a frequency expected from random usage, whereas in the CD5(-) population, VH4 appeared to be overrepresented in the nonproductive repertoire, and also negatively selected since it was found significantly less often in the productive compared to the nonproductive repertoire; the VH1 family was significantly diminished in the productive rearrangements of CD5(-) B cells. 3-23/DP-47 was the most frequently used VH gene segment and was found significantly more often than expected from random usage in productive rearrangements of both CD5(+) and CD5(-) B cells. Evidence for selection based on the D segment and the JH gene usage was noted in CD5(+) B cells. No differences were found between the B cell subsets in CDR3 length, the number of N-nucleotides or evidence of exonuclease activity. Somatically hypermutated VHDJH rearrangements were significantly more frequent and extensive in CD5(-) compared to CD5(+) IgM+ B cells, indicating that IgM+ memory B cells were more frequent in the CD5(-) B cell population. Of note, the frequency of specific VH genes in the mutated population differed from that in the nonmutated population, suggesting that antigen stimulation imposed additional biases on the repertoire of IgM+ B cells. These results indicate that the expressed repertoire of IgM+ B cell subsets is shaped by recombinational bias, as well as selection before and after antigen exposure. Moreover, the influences on the repertoires of CD5(+) and CD5(-) B cells are significantly different, suggesting that human peripheral blood CD5(+) and CD5(-) B cells represent different B cell lineages, with similarities to murine B-1a and B-2 subsets, respectively.

Molecular mechanisms and selective influences that shape the kappa gene repertoire of IgM+ B cells.

To analyze the human kappa chain repertoire and the influences that shape it, a single cell PCR technique was used that amplified Vkappa Jkappa rearrangements from genomic DNA of individual human B cells. More than 350 productive and 250 nonproductive Vkappa Jkappa rearrangements were sequenced. Nearly every functional Vkappa gene segment was used in rearrangements, although six Vkappa gene segments, A27, L2, L6, L12a, A17, and O12/O2 were used preferentially. Of these, A27, L2, L6, and L12a showed evidence of positive selection based on the variable region and not CDR3, whereas A17 was overrepresented because of a rearrangement bias based on molecular mechanisms. Utilization of Jkappa segments was also nonrandom, with Jkappa1 and Jkappa2 being overrepresented and Jkappa3 and Jkappa5 underrepresented in the nonproductive repertoire, implying a molecular basis for the bias. In B cells with two Vkappa Jkappa rearrangements, marked differences were noted in the Vkappa segments used for the initial and subsequent rearrangements, whereas Jkappa segments were used comparably. Junctional diversity was generated by n-nucleotide addition in 60% and by exonuclease trimming in 75% of the Vkappa Jkappa rearrangements analyzed. Despite this large degree of diversity, a strict CDR3 length was maintained in both productive and nonproductive rearrangements. More than 23% of the productive rearrangements, but only 7% of the nonproductive rearrangements contained somatic hypermutations. Mutations were significantly more frequent in Vkappa sequences derived from CD5- as compared with CD5+ B cells. These results document that the gene segment utilization within the Vkappa repertoire is biased by both intrinsic molecular processes as well as selection after light chain expression. Moreover, IgM+ memory cells with highly mutated kappa genes reside within the CD5- but not the CD5+ B cell compartment.

Analysis of the frequency and pattern of somatic mutations within nonproductively rearranged human variable heavy chain genes.

Somatic hypermutation plays an essential role in avidity maturation of Ab. To characterize the effects of hypermutation without the imposed bias of Ag-mediated selection, the mutational pattern of 37 nonproductively rearranged VH genes amplified from individual human B cells was analyzed. A high frequency of mutations as well as frequent replacement mutations were observed in the complementarity-determining regions (CDR) and in the framework regions of nonproductive VHDJH rearrangements. Comparison with 57 productive VH rearrangements indicated that replacement mutations, especially those occurring in the framework regions, were less frequent in productively rearranged VH genes, suggesting that they were deleted from the expressed repertoire. A number of factors contributed to the nonrandom localization of mutations, including: the targeting of specific motifs, such as AGY, GCY, GTA, TAY, and RGYW; an increased frequency of some commonly mutated motifs in the CDRs; and an apparent increased likelihood of mutations of CDR nucleotides. Each of these appeared to bias the mutational machinery, resulting in an increased frequency of replacement mutations in the CDRs of nonproductive VH rearrangements.