Lymphocyte depletion with fludarabine in patients with psoriatic arthritis: clinical and immunological effects

Purine antimetabolites associated Pneumocystis jirovecii pneumonia

PURPOSE

To detect the possible safety signal of purine antimetabolites associated with Pneumocystis jirovecii pneumonia through disproportionality analysis in the FDA Adverse Event Reporting System (FAERS) Database.

METHODS

A case/non-case retrospective disproportionality analysis was performed in the publicly available FAERS database using AERSmine (2004Q1-2021Q3). Four models were developed to explore the signal strength of PAs among different populations with possible confounding factors. Reporting odds ratio (ROR) and Proportional reporting ratio (PRR) was used as the data mining algorithm for the analysis. A value of ROR-1.96SE > 1 and PRR ≥ 2 with an associated X2 value of 4 or more was considered the threshold for a signal.

RESULTS

A total of 7073 reports associated with Pneumocystis jirovecii pneumonia were present in the database, of which 899 reports were associated with purine antimetabolites. A crude signal strength of ROR 15.76(14.70-16.91) was obtained for purine antimetabolites associated PJP, with the highest signal strength reported with fludarabine and thioguanine [ROR 19.63(17.42-22.13); 19.45(13.21-28.63)]. Stratifying the cases based on autoimmune disorders and the cancer population revealed an ROR of 3.33(2.46-4.50) and 2.93(2.26-3.79) respectively. The highest risk of PJP with use of PAs was observed amongst children with a higher risk of nearly 2 times than the adult population [ROR 11.57(9.16-14.62)].

CONCLUSIONS

Our study provided evidence on the occurrence of PJP with the use of purine antimetabolites among the autoimmune and cancer population. We identified signals for PJP with azathioprine, mercaptopurine, thioguanine, cladribine, fludarabine, and clofarabine. More research with a superior epidemiological study design of a defined population is required to validate these findings.

Interleukin-17A Is Produced by CD4+ but Not CD8+ T Cells in Synovial Fluid Following T Cell Receptor Activation and Regulates Different Inflammatory Mediators Compared to Tumor Necrosis Factor in a Model of Psoriatic Arthritis Synovitis

OBJECTIVE

Interleukin-17A (IL-17A) and tumor necrosis factor (TNF) contribute to the pathogenesis of psoriatic arthritis (PsA). However, their functional relationship in PsA synovitis has not been fully elucidated. Additionally, although CD8+ T cells in PsA have been recognized via flow cytometry as a source of IL-17A production, it is not clear whether CD8+ T cells secrete IL-17A under more physiologically relevant conditions in the context from PsA synovitis. This study was undertaken to clarify the roles of IL-17A and TNF in the synovial fluid (SF) from patients with PsA and investigate the impact of CD8+ T cells on IL-17A production.

METHODS

IL-17A+ T cells were identified by flow cytometry in SF samples from 20 patients with active PsA, blood samples from 22 treatment-naive patients with PsA, and blood samples from 22 healthy donors. IL-17A+ T cells were sorted from 12 PsA SF samples and stimulated using anti-CD3/anti-CD28 or phorbol myristate acetate (PMA) and ionomycin ex vivo, alone (n = 3) or together with autologous monocytes (n = 3) or PsA fibroblast-like synoviocytes (FLS) (n = 5-6). To evaluate the differential allogeneic effects of neutralizing IL-17A and TNF, SF CD4+ T cells and PsA FLS cocultures were also used (n = 5-6).

RESULTS

Flow cytometry analyses of SF samples from patients with PsA showed IL-17A positivity for CD4+ and CD8+ T cells (IL-17A, median 0.71% [interquartile range 0.35-1.50%] in CD4+ cells; median 0.44% [interquartile range 0.17-1.86%] in CD8+ T cells). However, only CD4+ T cells secreted IL-17A after anti-CD3/anti-CD28 activation, when cultured alone and in cocultures with PsA monocytes or PsA FLS (each P < 0.05). Remarkably, CD8+ T cells only secreted IL-17A after 4- or 72-hour stimulation with PMA/ionomycin. Anti-IL-17A and anti-TNF treatments both inhibited PsA synovitis ex vivo. Neutralizing IL-17A strongly inhibited IL-6 (P < 0.05) and IL-1β (P < 0.01), while anti-TNF treatment was more potent in reducing matrix metalloproteinase 3 (MMP-3) (P < 0.05) and MMP-13.

CONCLUSION

CD8+ T cells, in contrast to CD4+ T cells, in SF specimens obtained from PsA patients did not secrete IL-17A following T cell receptor activation. Overlapping, but distinct, effects at the level of inflammatory cytokines and MMPs were found after neutralizing IL-17A or TNF ex vivo in a human model of PsA synovitis.

Fatal Measles Virus Infection After Rituximab-Containing Chemotherapy in a Previously Vaccinated Patient

We report the case of a young patient treated with rituximab-containing chemotherapy who was infected with measles despite previous vaccination. Treatment with vitamin A, ribavirin, and immunoglobulins was started; nevertheless he developed severe pneumonitis and deceased. Broad vaccination coverage is crucial in protecting vulnerable subjects.

Bendamustine associated immune suppression and infections during therapy of hematological malignancies

Bendamustine is being increasingly used in patients with indolent non-Hodgkin lymphoma, mantle cell lymphoma and chronic lymphocytic leukemia. This review summarizes available evidence regarding the effects of bendamustine on the immune system, examines its role in consequent infections as reported in randomized controlled trials, prospective observational investigations, retrospective studies and individual published case reports. Myelosuppression including lymphopenia occurs relatively frequently after therapy with bendamustine. It is mostly CD4 + T cell counts that are suppressed, yet when given in combination with rituximab, both T cell and B cell depletion have been recorded. In addition, hypogammaglobulinemia after bendamustine therapy has also been reported. Variable infection rates have been documented and these include different bacterial, viral and fungal infections. Finally, we also consider issues relating to the use of prophylactic antibiotics in patients receiving the drug.

IgG4-related disease with hypergammaglobulinemic hyperviscosity and retinopathy

Immunoglobulin G4-related disease (IgG4-RD) is a recently described entity with protean manifestations. We describe a novel case of IgG4-RD with hypergammaglobulinemic hyperviscosity responsive to fludarabine and rituximab. A 33-year-old Asian man developed bilateral lacrimal gland and submandibular salivary gland swelling with cervical lymphadenopathy. Biopsies of the affected tissues revealed reactive follicular hyperplasia. Seven years later, he presented with bilateral retinal hemorrhages due to hyperviscosity syndrome from profound polyclonal increase in IgG, including marked IgG4 elevation. Despite plasmapheresis, overproduction of IgG continued and he was refractory to systemic steroids, azathioprine, interferon alpha, and cyclophosphamide. IgG4-RD was suspected following a myocardial infarction and detection of aneurysmal coronary arteries indicating large vessel vasculitis. Review of the cervical lymph node and lacrimal gland biopsies with immunohistochemical staining for IgG4-positive plasma cells confirmed IgG4-RD. B-cell depletion with rituximab produced a partial response, but clinical symptoms and elevated protein levels persisted. Fludarabine was added to rituximab to suppress T-cell activity, and this resulted in an excellent clinical and biochemical response. Combination therapy with fludarabine and rituximab in IgG4-RD has not previously been reported and can be considered in patients with severe refractory disease.

Synovial tissue response to treatment in psoriatic arthritis

Following its validation and wide application in rheumatoid arthritis (RA), synovial tissue analysis has recently been applied to studies on Psoriatic Arthritis (PsA). Such studies aim to thereby clarify its distinctive features and the nature of specific responses upon administration of disease modifying anti-rheumatic drug (DMARD) or biologic agents. In consequence, insights to disease pathogenesis, drugs' mechanisms of action (MOA) and biomarkers of response have emerged. Data from pilot and open-label studies, and recently from randomized controlled trials, have helped in refining the therapeutic approaches to PsA patients, by improving understanding of MOA and in provision of biomarkers of response. The availability of less invasive and reproducible analysis techniques to obtain and evaluate synovial biopsies will further enhance the utility of this approach in due course.

Impaired response to influenza vaccine associated with persistent memory B cell depletion in non-Hodgkin's lymphoma patients treated with rituximab-containing regimens

Influenza vaccination is generally recommended for non-Hodgkin's lymphoma (NHL) patients, but no data are available about the activity of this vaccine after treatment with rituximab-containing regimens. We evaluated the humoral response to the trivalent seasonal influenza vaccine in a group of NHL patients in complete remission for ≥6 mo (median, 29 mo) after treatment with rituximab-containing regimens (n = 31) compared with age-matched healthy subjects (n = 34). B cell populations and incidence of influenza-like illness were also evaluated. For each viral strain, the response was significantly lower in patients compared with controls and was particularly poor in patients treated with fludarabine-based regimens. In the patient group, the response to vaccination did not fulfill the immunogenic criteria based on the European Committee for Medicinal Products for Human Use requirements. Among the patients, CD27(+) memory B cells were significantly reduced, and their reduction correlated with serum IgM levels and vaccine response. Episodes of influenza-like illness were recorded only in patients. These results showed that NHL patients treated with rituximab-containing regimens have persisting perturbations of B cell compartments and Ig synthesis and may be at particular risk for infection, even in long-standing complete remission.

Fludarabine modulates composition and function of the T cell pool in patients with chronic lymphocytic leukaemia

The combination of cytotoxic treatment with strategies for immune activation represents an attractive strategy for tumour therapy. Following reduction of high tumour burden by effective cytotoxic agents, two major immune-stimulating approaches are being pursued. First, innate immunity can be activated by monoclonal antibodies triggering antibody-dependent cellular cytotoxicity. Second, tumour-specific T cell responses can be generated by immunization of patients with peptides derived from tumour antigens and infused in soluble form or loaded onto dendritic cells. The choice of cytotoxic agents for such combinatory regimens is crucial since most substances such as fludarabine are considered immunosuppressive while others such as cyclophosphamide can have immunostimulatory activity. We tested in this study whether fludarabine and/or cyclophosphamide, which represent a very effective treatment regimen for chronic lymphocytic leukaemia, would interfere with a therapeutic strategy of T cell activation. Analysis of peripheral blood samples from patients prior and during fludarabine/cyclophosphamide therapy revealed rapid and sustained reduction of tumour cells but also of CD4(+) and CD8(+) T cells. This correlated with a significant cytotoxic activity of fludarabine/cyclophosphamide on T cells in vitro. Unexpectedly, T cells surviving fludarabine/cyclophosphamide treatment in vitro had a more mature phenotype, while fludarabine-treated T cells were significantly more responsive to mitogenic stimulation than their untreated counterparts and showed a shift towards T(H)1 cytokine secretion. In conclusion, fludarabine/cyclophosphamide therapy though inducing significant and relevant T cell depletion seems to generate a micromilieu suitable for subsequent T cell activation.

Psoriatic Arthritis: A Review

Psoriatic arthritis (PsA) is a seronegative inflammatory spondyloarthropathy occurring in individuals with psoriasis. Psoriasis precedes joint disease in approximately 80% of PsA cases. The clinical course of PsA varies from mild arthritis to a severe, debilitating erosive arthropathy that affects functional capacity and quality of life of patients. The incidence of PsA is gender neutral, but a significant genetic component exists. Hallmark clinical features include dystrophic nail changes in the fingers or toes, dactylitis, and enthesitis. Many drugs indicated for use in rheumatoid arthritis have been found useful in the treatment of PsA, suggesting a similar immune-mediated etiology. Nonsteroidal anti-inflammatory drugs and intraarticular corticosteroids are often sufficient to manage mild PsA. Moderate to severe forms of the disease require the initiation of disease modifying anti-rheumatic drugs. Failure of two disease modifying antirheumatic drugs justifies the initiation of biologic therapy with tumor necrosis factor-α inhibitors.

High incidence of non-neutropenic infections induced by rituximab plus fludarabine and associated with hypogammaglobulinemia: a frequently unrecognized and easily treatable complication

BACKGROUND

Rituximab is associated with low incidence of hypogammaglobulinemia and little morbidity. Our experience with the combination of rituximab + chemotherapy suggested the opposite.

PATIENTS AND METHODS

We analyzed our experience with rituximab plus chemotherapy in 97 patients to determine: frequency and type of non-neutropenic infection (NNI); frequency and type of hypogammaglobulinemia; response to gammaglobulin therapy; and factors associated with NNI.

RESULTS

We observed 40 episodes of NNI in 19 of 97 (20%) patients. By 3 years, 43% of patients treated with rituximab + chemotherapy were projected to have developed at least one NNI. Of 19 with NNI, 15 had Ig levels studied and all 15 had hypogammaglobulinemia. Most frequently affected Ig were IgG (14 of 15) and IgM (13 of 14). IgA was usually spared (six of 14 cases affected). NNIs observed were 18 bronchitis, 16 sinusitis, four pneumonias, three otitis media, two fevers of unknown origin (FUOs) and three herpes zoster. Hospitalization was required in seven of 19. Ten received gammaglobulin infusions and all responded promptly. Gammaglobulin was given only when NNIs recurred. We examined sex, age, histology, type of rituximab-chemotherapy (fludarabine + rituximab versus other chemotherapy + rituximab) for correlation with NNI.

CONCLUSIONS

Indolent histology, female sex and fludarabine + rituximab significantly correlated with frequency of NNI but multivariate analysis picked fludarabine + rituximab followed by female gender as the only two independent variables predictive of NNI.

Signaling molecules and cytokine production in T cells of patients with B-cell chronic lymphocytic leukemia: long-term effects of fludarabine and alemtuzumab treatment

Fludarabine and alemtuzumab are routinely used for treatment of B-cell chronic lymphocytic leukemia (B-CLL). The present study aimed to compare the expression of signaling molecules and cytokine production by T cells of B-CLL patients in long-term unmaintained remission/plateau phase following fludarabine or alemtuzumab treatment with that of indolent/untreated B-CLL patients and healthy donors. The frequency and intensity of TCR-CD3zeta chain, p56lck, p59fyn, ZAP-70, PI3-kinase and interferon (IFN)-gamma/interleukin (IL)-4 production in CD4 and CD8 T cells was examined by flow cytometry. T-cell function was assessed by stimulation with purified protein derivative (PPD) and phytohemagglutinin (PHA). Despite a reduction in number, the expression of IFN-gamma/IL-4 in T-cells in patients was significantly higher than in healthy donors. The intensity of most signaling molecules in treated patients was relatively unaffected vs. healthy donors but lower than untreated-indolent patients. However, the total number of T cells which expressed each of the signaling molecules was decreased in patients, with no difference between fludarabine- and alemtuzumab-treated patients. The T-cell response to PHA but not PPD was reduced in treated patients. The results suggest that, despite some alterations in signaling molecules and a reduction in T-cell number, overall T-cell functions may be relatively well preserved long-term after treatment with fludarabine and alemtuzumab.

[Mechanisms and treatment of psoriasis]

Psoriasis is a common dermatosis that affects 3-5% of the European population. Current treatments offer considerable clinical benefits, but their use is limited due to tolerance problems. Recent years have seen the development of new treatments, used separately or in combination to improve the chronic lesions caused by this disease. T cells play an important role in the pathogenesis of psoriasis. Various techniques target the T cells and the immunological mechanisms involved in their activation. In 2005, treatment of psoriasis is directed essentially towards immunological pathways.

Treatment advances in psoriatic arthritis

Treatment of psoriatic arthritis, like the treatment of rheumatoid arthritis, now commonly includes the use of inhibitors of tumor necrosis factor in addition to traditional synthetic disease-modifying antirheumatic drugs. This paper examines the most recent data from therapeutic trials in psoriatic arthritis, with particular emphasis on the effectiveness of the tumor necrosis factor inhibitors. Recent data on potential future therapies is discussed as well, along with data on the mechanisms of current therapies that may have relevance for future treatment approaches.

Preclinical experiments

The clinical use of autologous stem cell transplants for the treatment of refractory severe autoimmune diseases was preceded by convincing proof of its underlying principle in animal models. The various categories of experimental autoimmune disease in laboratory rodents are briefly described here, and the rationale that was used in the selection of suitable experimental autoimmune diseases for translational research is explained. The two models that provided the bulk of the data needed for designing the initial clinical treatment protocols were adjuvant arthritis (AA) and experimental allergic encephalomyelitis (EAE), which were both induced in Buffalo rats. In this strain, AA is manifested as a chronic, progressive, systemic polyarthritis and EAE as a chronic, remitting/relapsing form of encephalomyelitis resembling multiple sclerosis. Both diseases can be cured with autologous stem cell transplantation provided that adequate conditioning is given and that the disease has not yet progressed to the stage of 'scarring'. It is basically the inflammatory stages that respond well to this therapy. The success of treatment depends on how completely the autoantigen-specific activated T-lymphocytes and memory cells are eradicated. Because of a lack of information on the nature of the autoantigens involved in human disease and on the size of those cell populations in the animal models as well as in humans, this aspect of translation is difficult. The experiments have, however, provided important guidelines. High-dose conditioning regimens yield better results than low-dose conditioning, certain conditioning agents perform better than others, and care should be taken not to reintroduce too many T-cells with the autologous graft. The clinical results obtained so far indicate a high predictive power of these two animal models, which are therefore recommended strongly for additional preclinical studies.