Granulocyte colony-stimulating factor induction of improved leukocytopenia with inflammatory flare in a Felty's syndrome patient

Balancing Benefits and Risks: A Literature Review on Hypersensitivity Reactions to Human G-CSF (Granulocyte Colony-Stimulating Factor)

Human granulocyte colony-stimulating factor (G-CSF) is a granulopoietic growth factor used in the treatment of neutropenia following chemotherapy, myeloablative treatment, or healthy donors preparing for allogeneic transplantation. Few hypersensitivity reactions (HRs) have been reported, and its true prevalence is unknown. We aimed to systematically characterize G-CSF-induced HRs while including a comprehensive list of adverse reactions. We reviewed articles published before January 2024 by searching in the PubMed, Embase, Cochrane Library, and Web of Science databases using a combination of the keywords listed, selected the ones needed, and extracted relevant data. The search resulted in 68 entries, 17 relevant to our study and 7 others found from manually searching bibliographic sources. A total of 40 cases of G-CSF-induced HR were described and classified as immediate (29) or delayed (11). Immediate ones were mostly caused by filgrastim (13 minimum), with at least 9 being grade 5 on the WAO anaphylaxis scale. Delayed reactions were mostly maculopapular exanthemas and allowed for the continuation of G-CSF. Reactions after first exposure frequently appeared and were present in at least 11 of the 40 cases. Only five desensitization protocols have been found concerning the topic at hand in the analyzed data. We believe this study brings to light the research interest in this topic that could benefit from further exploration, and propose regular updating to include the most recently published evidence.

Felty's Syndrome, Insights and Updates

Felty’s syndrome (FS) is characterized by the triad of seropositive rheumatoid arthritis (RA) with destructive joint involvement, splenomegaly and neutropenia. Current data shows that 1-3 % of RA patients are complicated with FS with an estimated prevalence of 10 per 100,000 populations. The complete triad is not an absolute requirement, but persistent neutropenia with an absolute neutrophil count (ANC) generally less than 1500/mm3 is necessary for establishing the diagnosis. Felty’s syndrome may be asymptomatic but serious local or systemic infections may be the first clue to the diagnosis. FS is easily overlooked by parallel diagnoses of Sjӧgren syndrome or systemic lupus erythematosus or lymphohematopoietic malignancies. The role of genetic (HLA DR4) is more prominent in FS in comparison to classic rheumatoid arthritis. There is large body of evidence that in FS patients, both cellular and humoral immune systems participate in neutrophil activation, and apoptosis and its adherence to endothelial cells in the spleen. It has been demonstrated that proinflammatory cytokines may have inhibitory effects on bone marrow granulopoiesis. Binding of IgGs to neutrophil extracellular chromatin traps (NET) leading to neutrophil death plays a crucial role in its pathophysiology. In turn, "Netting" neutrophils may activate auto-reactive B cells leading to further antibody and immune complex formation. In this review we discuss on basic pathophysiology, epidemiology, genetics, clinical, laboratory and treatment updates of Felty’s syndrome.

Management of autoimmune neutropenia in Felty's syndrome and systemic lupus erythematosus

Autoimmune neutropenia, caused by neutrophil-specific autoantibodies is a common phenomenon in autoimmune disorders such as Felty's syndrome and systemic lupus erythematosus. Felty's syndrome is associated with neutropenia and splenomegaly in seropositive rheumatoid arthritis which can be severe and with recurrent bacterial infections. Neutropenia is also common in systemic lupus erythematosus and it is included in the current systemic lupus classification criteria. The pathobiology of the autoimmune neutropenia in Felty's syndrome and systemic lupus erythematosus is complex, and it could be a major cause of morbidity and mortality due to increased risk of sepsis. Treatment should be individualized on the basis of patient's clinical situation, and prevention or treatment of the infection. Recombinant human granulocyte colony-stimulating factor is a safe and effective therapeutic modality in management of autoimmune neutropenia associated with Felty's syndrome and systemic lupus erythematosus, which stimulates neutrophil production. There is a slight increased risk of exacerbation of the underlying autoimmune disorder, and recombinant human granulocyte colony-stimulating factor dose and frequency should be adjusted at the lowest effective dose.

Cyclooxygenases and prostaglandins: shaping up the immune response

The relevance of cyclooxygenases (COX)-1 and -2 and their products to inflammation, thrombosis and gastroprotection are well known. Their importance in the immune response was first recognized more than 25 years ago, but has only gained widespread attention recently. In this review, we attempt to integrate information on prostanoids and both the innate and acquired immune responses, including effects on leukocytes, antigen presenting cells, dendritic cells, T and B lymphocytes. Prostanoids may be relevant to immunotolerance, autoimmune disorders, transplantation, immunologic defense against tumors, acquired immunodeficiencies and viral infections. Insight into the role of prostanoids in immune function may afford novel therapeutic opportunities.

Treatment of severe neutropenia due to Felty's syndrome or systemic lupus erythematosus with granulocyte colony-stimulating factor

OBJECTIVES

To examine the efficacy and safety of recombinant human granulocyte colony-stimulating factor (rhG-CSF) and recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) for the treatment of severe neutropenia due to Felty's syndrome (FS) or systemic lupus erythematosus (SLE).

METHODS

Eight patients with absolute neutrophil counts (ANC) below 1,000/microL attributable to FS (n = 4) or SLE (n = 4) were treated with rhG-CSF. The hematologic and clinical response as well as side effects were recorded. In addition, reports on the use of rhG-CSF/rhGM-CSF in FS and SLE retrieved from the English language literature were analyzed.

RESULTS

RhG-CSF effectively corrected neutropenia due to FS and SLE in seven of the current eight patients. In 54 of 55 FS and SLE patients retrieved from the literature, G-CSF or GM-CSF, respectively, proved to be effective at elevating the neutrophil count, which was often associated with improvement of infectious complications. The neutrophil count often declined again when growth factor treatment was stopped but generally stabilized at a level that exceeded the pretreatment count. Side effects included rare cases of thrombocytopenia, arthralgias, and development of cutaneous leukocytoclastic vasculitis. Side effects were dose dependent and resolved when treatment was discontinued. One of our own patients and 17 previously reported patients continued to benefit from long-term administration of rhG-CSF over periods of more than 40 months.

CONCLUSIONS

RhG-CSF is an effective and generally well-tolerated treatment for neutropenia due to FS or SLE. Exacerbation of the underlying rheumatic condition due to G-CSF appears to be rare if G-CSF is administered at the lowest dose effective at elevating the ANC above 1,000/microL.

Development of rheumatoid arthritis after treatment of large granular lymphocyte leukemia with deoxycoformycin

The association of T-cell large granular lymphocyte (LGL) leukemia and rheumatoid arthritis is well described and it is now recognized that these patients and patients with Felty's syndrome represent different aspects of a single disease process. Most patients have rheumatoid arthritis at the time of diagnosis of LGL leukemia. This is the first detailed report of the development of rheumatoid arthritis after the diagnosis and treatment of LGL leukemia as well as the first report of rheumatoid arthritis that occurred in association with deoxycoformycin treatment. It is likely that the beneficial sustained normalization of neutrophil counts as a result of deoxycoformycin treatment played a significant role in the development of this complication. Hematological improvement occurred despite molecular genetic evidence of persistence of the abnormal T-cell clone. The role of the clonally expanded T cells in the pathogenesis of neutropenia and rheumatoid arthritis is discussed.

A phase 1 study to address the safety and efficacy of granulocyte colony-stimulating factor for the mobilization of hematopoietic progenitor cells in active rheumatoid arthritis

OBJECTIVE

To examine the safety and efficacy of granulocyte colony-stimulating factor (G-CSF) alone for the mobilization of peripheral blood progenitor cells in patients with resistant active rheumatoid arthritis (RA).

METHODS

Five patients with resistant active RA were studied. A dose of 5 microg/kg of G-CSF (Filgrastim) was given subcutaneously each day for 5 days, and the number of stem cells mobilized into the peripheral blood was assessed by daily CD34 counts. RA disease activity was assessed by standard clinical methods.

RESULTS

The absolute numbers of peripheral blood CD34+ cells peaked on day 4, with a mean value of 0.025 x 10(9)/liter (range 0.013-0.048 x 10(9)/liter). There was no significant change in disease activity during the study or in the month following therapy.

CONCLUSION

Using G-CSF alone, CD34+ progenitor peripheral blood cells were mobilized in numbers suitable for leukopheresis. G-CSF therapy was well-tolerated in patients with active RA, and was not associated with a flare during treatment or in the month following treatment.

Cytokine-induced autoimmune disorders

Cytokines are now commonly used in the treatment of many conditions, especially cancer, haematological malignancies and chronic viral hepatitis. With some of these cytokines, clinical induction and/or exacerbation of autoimmune manifestations have been observed. This has been the case with interferon-alpha and interferon-gamma, interleukin-2 and some colony-stimulating factors. All known biological and clinical autoimmune features have been observed but thyroid abnormalities have been particularly frequent. Some of these manifestations appear to be related to the effect of these exogenous cytokines on the T helper cell (TH) 1/TH2-cytokine balance and the regulatory properties of these cells. Patients with a history of underlying autoimmune disease or baseline serological abnormalities should be monitored for autoimmunity when treated with certain TH1 or TH2-inducing cytokines.

Regulation by Interleukin-10 and Interleukin-4 of Cyclooxygenase-2 Expression in Human Neutrophils

Neutrophils are important effector cells of acute inflammation because of their potential capacity to synthesize various proinflammatory mediators, and inhibition of their production is expected to result in anti-inflammatory effects. In this study, we investigate the effects of the anti-inflammatory cytokines, interleukin-10 (IL-10) and IL-4, on prostanoid synthesis in human neutrophils. Neutrophils isolated from healthy donors constitutively produced a small amount of prostaglandin E2 (PGE2 ) without any stimulations, whereas they produced a large amount of PGE2 after lipopolysaccharide (LPS) stimulation. IL-10 and IL-4 selectively inhibited their LPS-induced PGE2 production. Inhibition by both cytokines occurred at an early stage of LPS stimulation. Anti–IL-10 treatment of LPS-stimulated neutrophils resulted in enhanced PGE2 production. LPS-induced PGE2 and thromboxane B2 (TXB2 ) production in aspirin-treated neutrophils was significantly inhibited by IL-10, IL-4, and NS-398. Moreover, IL-10 and IL-4 inhibited LPS-induced cyclooxygenase (COX) activity in neutrophils. Western blot and immunocytochemical analysis showed that COX-2 protein was clearly induced in LPS-stimulated neutrophils and that its induction was inhibited by both IL-10 and IL-4. Moreover, both of these cytokines inhibited COX-2 mRNA expression in LPS-stimulated neutrophils. These results raise the possibility that these two cytokines may both offer potent clinical utility as anti-inflammatory agents in the future.

Regulation by Interleukin-10 and Interleukin-4 of Cyclooxygenase-2 Expression in Human Neutrophils

Neutrophils are important effector cells of acute inflammation because of their potential capacity to synthesize various proinflammatory mediators, and inhibition of their production is expected to result in anti-inflammatory effects. In this study, we investigate the effects of the anti-inflammatory cytokines, interleukin-10 (IL-10) and IL-4, on prostanoid synthesis in human neutrophils. Neutrophils isolated from healthy donors constitutively produced a small amount of prostaglandin E2 (PGE2 ) without any stimulations, whereas they produced a large amount of PGE2 after lipopolysaccharide (LPS) stimulation. IL-10 and IL-4 selectively inhibited their LPS-induced PGE2 production. Inhibition by both cytokines occurred at an early stage of LPS stimulation. Anti–IL-10 treatment of LPS-stimulated neutrophils resulted in enhanced PGE2 production. LPS-induced PGE2 and thromboxane B2 (TXB2 ) production in aspirin-treated neutrophils was significantly inhibited by IL-10, IL-4, and NS-398. Moreover, IL-10 and IL-4 inhibited LPS-induced cyclooxygenase (COX) activity in neutrophils. Western blot and immunocytochemical analysis showed that COX-2 protein was clearly induced in LPS-stimulated neutrophils and that its induction was inhibited by both IL-10 and IL-4. Moreover, both of these cytokines inhibited COX-2 mRNA expression in LPS-stimulated neutrophils. These results raise the possibility that these two cytokines may both offer potent clinical utility as anti-inflammatory agents in the future.

Treatment of the neutropenia of Felty syndrome

This review sets out to synthesize and critically evaluate the current reported data regarding therapeutic options for the neutropenia associated with Felty syndrome (Felty neutropenia). A MEDLINE search and bibliographies from recent reviews were used to identify trials and case reports that provided sufficient data to evaluate the effect of various interventions on both the neutropenia and the clinical course of patients with Felty syndrome. Data were obtained on baseline hematologic profiles, bone-marrow biopsies, and patient characteristics; length of follow-up; hematologic and clinical responses to the various interventions; and side-effect profiles. Treatment with hemopoietic growth factors or methotrexate can produce sustained hematologic and clinical responses with an acceptable side-effect profile. Splenectomy produces a long-term hematologic response in 80% of patients. Patients who do not respond hematologically have a higher incidence of non-fatal infections, but a significant minority (46%) do not experience any infections; the incidence of fatal infections is 12%, regardless of whether a hematologic response occurs. Of the patients who had infections prior to surgery, 55% did not experience further infections after splenectomy. Initial treatment of Felty neutropenia should consist of hemopoietic growth factors because of their rapid onset of action and relatively low incidence of side-effects. Splenectomy is a reasonable option if growth factors are ineffective and rapid amelioration of neutropenia is needed. Methotrexate offers a potentially promising alternative for the treatment of both the rheumatologic and the hematologic manifestations of Felty syndrome.

Effects of antirheumatic agents on cytokines

A review of the literature concerning the effects of traditional antirheumatic drugs on cytokines and the cytokine and anticytokine approaches already used in the therapy of rheumatoid arthritis (RA) is presented. Many antirheumatic drugs are capable of cytokine modulation in vitro. Corticosteroids inhibit the transcription of a broad spectrum of genes including those encoding monocyte, T cell-derived cytokines and several hemopoietic growth factors, whereas drugs such as cyclosporin A and D-penicillamine interfere with T cell activation more specifically by suppressing interleukin 2 (IL-2) production. The in vivo effects of drug therapy on cytokines in RA patients are less well established. Gold compounds reduce circulating IL-6 levels and the expression of monocyte-derived cytokines, such as IL-1, tumor necrosis factor (TNF), and IL-6, in the rheumatoid synovium. Decreases in circulating IL-6, soluble IL-2 (sIL-2R), and TNF receptors and in synovial fluid IL-1 levels have been reported with methotrexate. Reductions in circulating IL-6 and sIL-2R concentrations have also been observed with cyclosporin and corticosteroids, whereas azathioprine reduces IL-6 but not sIL-2R. Studies on sulfasalazine are conflicting and the in vivo effects of D-penicillamine and antimalarials have not been studied yet. Interferon gamma therapy is not effective in RA but may prove a useful antifibrotic for systemic sclerosis. Colony stimulating factors improve the granulocytopenia associated with Felty's syndrome or drug toxicities but can induce arthritis flares and should be reserved to treat infectious complications. Promising results are being obtained with selective antagonism of TNF and IL-1 in RA, and combinations of anticytokine strategies with traditional antirheumatic drugs have been already envisaged. These should preferably be based in a broader knowledge of the effects of antirheumatic agents on the cytokine network.

The clinical utility of granulocyte colony-stimulating factor: early achievements and future promise

Recombinant granulocyte colony-stimulating factor (rHuG-CSF) is a hematopoietic growth factor that acts selectively on the neutrophil lineage, and has had a major impact on clinical practice. Two forms are in clinical use: filgrastim has been approved for use in more than 45 countries for the amelioration of chemotherapy-induced neutropenia and restoration of granulopoiesis following bone-marrow transplantation and lenograstim has been approved in Europe and Japan. In some countries, rHuG-CSF is also approved for various other indications, such as severe chronic neutropenia. Infection and neutropenia are a major cause of morbidity and mortality following cytotoxic chemotherapy, and there is a known correlation between neutropenia and the risk of infection. Hematopoietic growth factors have been used successfully in the prevention and treatment of neutropenia. There is evidence to suggest that use of rHuG-CSF before the onset of neutropenia allows patients to receive the maximum benefit; however, patients who do not receive rHuG-CSF prophylactically still benefit from the use of rHuG-CSF for the treatment of febrile neutropenia. These patients have an accelerated neutrophil recovery and a shorter duration of febrile neutropenia. These effects seem to translate into a significant reduction in the number of patients requiring prolonged hospitalization. This paper reviews the use of rHuG-CSF in the treatment of febrile neutropenia and describes how it is routinely used by hematologists and oncologists in non-clinical trial settings.