Selective inhibition of granulopoiesis with severe neutropenia in systemic lupus erythematosus

Zytopenien

Hematological alterations can often be observed during rheumatic diseases. The effects can be clinically severe, ranging from anemia of different grades of severity, through increased risk of hemorrhage due to thrombocytopenia up to severe infections as a result of high-grade leukocytopenia. The clinical sequelae for patients are predominantly determined by the extent of cytopenia. The underlying disease itself can initially be considered as the cause. Examples are anemia as a result of chronic inflammation, antibody-mediated thrombocytopenia as in systemic lupus erythematosus (SLE) or granulocytopenia within the framework of Felty's syndrome. Immunosuppressive treatment also often leads to alterations in the blood constituents. Although some substances, such as cyclophosphamide can suppress all three cell types, there are also selective effects, such as isolated thrombocytopenia under treatment with tocilizumab and JAK inhibitors. The differential diagnostic clarification of cytopenia can be difficult and necessitates a systematic work-up of the course of the disease and the subsequent treatment. The reviews of anemia, leukocytopenia and thrombocytopenia presented here summarize the most important components of the differentiation of hematological alterations in patients with rheumatic diseases.

Haematological manifestations of lupus

Our purpose was to compile information on the haematological manifestations of systemic lupus erythematosus (SLE), namely leucopenia, lymphopenia, thrombocytopenia, autoimmune haemolytic anaemia (AIHA), thrombotic thrombocytopenic purpura (TTP) and myelofibrosis. During our search of the English-language MEDLINE sources, we did not place a date-of-publication constraint. Hence, we have reviewed previous as well as most recent studies with the subject heading SLE in combination with each manifestation. Neutropenia can lead to morbidity and mortality from increased susceptibility to infection. Severe neutropenia can be successfully treated with granulocyte colony-stimulating factor. While related to disease activity, there is no specific therapy for lymphopenia. Severe lymphopenia may require the use of prophylactic therapy to prevent select opportunistic infections. Isolated idiopathic thrombocytopenic purpura maybe the first manifestation of SLE by months or even years. Some manifestations of lupus occur more frequently in association with low platelet count in these patients, for example, neuropsychiatric manifestation, haemolytic anaemia, the antiphospholipid syndrome and renal disease. Thrombocytopenia can be regarded as an important prognostic indicator of survival in patients with SLE. Medical, surgical and biological treatment modalities are reviewed for this manifestation. First-line therapy remains glucocorticoids. Through our review, we conclude glucocorticoids do produce a response in majority of patients initially, but sustained response to therapy is unlikely. Glucocorticoids are used as first-line therapy in patients with SLE with AIHA, but there is no conclusive evidence to guide second-line therapy. Rituximab is promising in refractory and non-responding AIHA. TTP is not recognised as a criteria for classification of SLE, but there is a considerable overlap between the presenting features of TTP and SLE, and a few patients with SLE have concurrent TTP. Myelofibrosis is an uncommon yet well-documented manifestation of SLE. We have compiled the cases that were reported in MEDLINE sources.

Neutrophils in the pathogenesis and manifestations of SLE

Systemic lupus erythematosus (SLE) is an autoimmune disease of unclear etiology that affects mostly women of childbearing age. Profound abnormalities in both innate and adaptive immunity triggered by genetic and environmental factors are well documented to play an important part in the pathogenesis of SLE. Nonetheless, the role of neutrophils--the most abundant immune cell type--in the pathology of this disease has been unclear. Over the past decade, compelling evidence has emerged that implicates neutrophils in the initiation and perpetuation of SLE and also in the resultant organ damage frequently observed in patients with this disease. SLE-derived low-density granulocytes (LDGs) induce vascular damage and synthesize increased amounts of type I interferons and, as such, could play a prominent part in the pathogenesis of SLE. Furthermore, increased cell death and enhanced extracellular trap formation observed in SLE-derived neutrophils might have key roles in the induction of autoimmunity and the development of organ damage in patients with SLE. Together, these events could have significant deleterious effects and promote aberrant immune responses in this disease. This Review highlights the role of neutrophils in the pathogenesis of SLE, with a particular focus on the putative deleterious effects of LDGs and neutrophil extracellular trap formation.

Agranulocytosis in Sjögren's syndrome: two case reports and analysis of 11 additional reported cases

OBJECTIVES

To report 2 patients who presented with agranulocytosis that was found to be immune-mediated and associated with occult primary Sjögren's syndrome (primary SS) and to identify and study similar cases reported in the literature.

METHODS

Two patients encountered in 2 large medical centers over a period of 5 years were studied in detail. All reported cases of agranulocytosis in primary SS identified through a MEDLINE search were reviewed.

RESULTS

Two patients presented with marked systemic symptoms alone or associated with recurrent infections. Agranulocytosis with either a pattern of maturation arrest or a hypercellular reactive bone marrow was found and was associated with "acute phase" markers, hypergammaglobulinemia, a small paraprotein peak, and high rheumatoid factor titers. A diagnosis of immune-mediated agranulocytosis associated with an occult primary SS was established and was successfully treated with intravenous immunoglobulins or prednisone. Both patients subsequently developed skin vasculitis. This rare association of agranulocytosis and Sjögren's syndrome was identified in 11 other cases and was the presenting manifestation of primary SS in 10 of 13 (77%) patients.

CONCLUSIONS

Agranulocytosis should be recognized as a rare but well-established association of primary SS. Bone marrow neutrophil production may be affected, or neutrophils may be destroyed in the circulation, by both humoral and cellular immune-mediated mechanisms. Agranulocytosis or neutropenia should be added to the varied hematologic manifestations of primary SS and may be its presenting feature and an important clue to diagnosis.

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.

Preliminary report: rhG-CSF may reduce the incidence of neonatal sepsis in prolonged preeclampsia-associated neutropenia

OBJECTIVES

To determine whether adjunctive therapy with recombinant human granulocyte colony-stimulating factor (rhG-CSF) could reverse the neutropenia and reduce the incidence of sepsis (</=28 days postnatal age) in neonates with prolonged preeclampsia-associated neutropenia compared with conventional therapy.

STUDY DESIGN

An intravenous infusion of rhG-CSF (10 microgram/kg/day x 3 days for 10 neonates or 5 microgram/kg/day x 3 days for 5 neonates) was administered to ventilated patients with prolonged (>/=3 consecutive days in the first postnatal week) preeclampsia-associated neutropenia (absolute neutrophil count [ANC] <1500/mm3). Neutrophilic responses and the incidence of neonatal sepsis in the next 28 postnatal days were compared with 13 case-matched control neonates who also had prolonged preeclampsia-associated neutropenia. Sepsis was defined as at least one positive blood culture in a newly symptomatic neonate treated with antibiotics for >/=7 days.

RESULTS

No significant differences existed among the three groups in the birth weight, gestational age, sex, growth retardation, method of delivery, magnitude of respiratory support, use of surfactant, usage of intravascular catheters, or in the initial (pretreatment) ANC. The average baseline ANC (pretreatment) in the 10 microgram rhG-CSF group was 815 +/- 169/mm3 (mean +/- SEM), in the 5 microgram group it was 786 +/- 165/mm3, and in the conventional group it was 965 +/- 283. Eighteen of 28 (64%) neonates with preeclampsia-associated neutropenia were neutropenic at birth, the other 10 (36%) had normal neutrophil counts at birth but subsequently developed >/=3 days of neutropenia between 24 and 120 hours after birth. The ANC increased by 2-fold at 24 hours, by 4-fold at 72 hours, and 14-fold by the 7th day in the 10-microgram group. In the 5-microgram group, a 2-fold and 5-fold increase occurred at 72 hours and 7 days, respectively. In the conventionally-treated group, only a 4-fold increase was seen as late as 7 days after achieving entry criteria. Sepsis was observed in 13% (2/15) of the rhG-CSF-treated neonates compared with an incidence of 54% (7/13) in the conventionally-treated neonates. Conclusions. rhG-CSF increases the ANC significantly (at 10 microgram/kg/day x 3 days) and reduces the incidence of neonatal sepsis in critically ill ventilated neonates with prolonged preeclampsia-associated neutropenia when compared with conventional therapy. A future prospective, randomized, and blinded trial is needed to validate the beneficial effects of prophylactic rhG-CSF therapy in neonates with prolonged preeclampsia-associated neutropenia.

Suppression of haematopoiesis by IgG autoantibodies from patients with systemic lupus erythematosus (SLE)

The inhibiting activity of serum on haematopoiesis has been described in patients with SLE. To explore further the features of serum inhibitor, we first examined the suppression of granulocytic and erythroid colony formation in vitro by serum from patients with SLE using methylcellulose culture. The potent inhibiting activity was demonstrated in six of 20 patients. All of these six patients were associated with leukocytopenia and/or anaemia. Five of 10 sera from patients with active SLE suppressed the colony formation of both burst-forming units of erythrocyte (BFU-E) and colony-forming units of granulocyte/macrophage (CFU-GM), and one serum suppressed BFU-E only. IgG fraction isolated from sera with inhibiting activity suppressed colony formation without complement involvement. The elimination of monocytes and lymphocytes from target mononuclear cells did not affect the suppression by the IgG fractions. The suppressive effect was completely eliminated after incubation of the IgG fractions with progenitor-enriched mononuclear cells. Flow cytometric analysis showed these IgG bound to CD34+ haematopoietic progenitor cells, but not to CD33+ cells. These data suggest that (i) the inhibitor of colony formation in serum was observed in IgG fraction; (ii) its suppressive effect on colony formation was mediated by neither monocytes and lymphocytes nor complements; and (iii) IgG fraction could bind to primitive haematopoietic progenitor cells and suppress the growth of these cells. Thus, IgG autoantibodies to primitive haematopoietic progenitor cells are demonstrated to be present in the sera of a significant proportion of active SLE patients with anaemia and leukocytopenia and to suppress the progenitor cell growth.