Cyclic neutropenia and T lymphocyte suppression of granulopoiesis: abrogation of the neutropenic cycles by lithium carbonate

Review of lithium effects on immune cells

One of the remarkable discoveries in the field of psychopharmacology from late 1940s is Lithium (Li) that reminds of old but still gold. It continues to be a distinctive mood stabilizer that matches various standards recommended for mood stabilizers. Apart from this Li is also known to affect immune cell functions. Lithium response and regulations of different immune cells in bipolar patients, related immune disorders are not well defined. Here, we provide an overview of literature with regard to Li's effects on different immune cells. However, the use of Li is currently limited to bipolar disorders and there is no empirical evidence for immune cell disorders. The objective of this article is to provide the evaluations of Li responses towards the different immune cells based on the existing studies. Further, more studies are needed to understand the mechanistic basis and heterogeneous responses of Li's effect in bipolar, also unravel relative immune disorders.

Oral ezatiostat HCl (Telintra®, TLK199) and idiopathic chronic neutropenia (ICN): a case report of complete response of a patient with G-CSF resistant ICN following treatment with ezatiostat, a glutathione S-transferase P1-1 (GSTP1-1) inhibitor

Idiopathic chronic neutropenia (ICN) describes a heterogeneous group of hematologic diseases characterized by low circulating neutrophil levels often associated with recurrent fevers, chronic mucosal inflammation, and severe systemic infections. The severity and risk of complications, including serious infections, are inversely proportional to the absolute neutrophil count (ANC), with the greatest problems occurring in patients with an ANC of less than 0.5 × 10⁹/L. This case report describes a 64-year-old female with longstanding rheumatoid arthritis who subsequently developed ICN with frequent episodes of sepsis requiring hospitalization and prolonged courses of antibiotics over a 4-year period. She was treated with granulocyte colony stimulating factors (G-CSF) but had a delayed, highly variable, and volatile response. She was enrolled in a clinical trial evaluating the oral investigational agent ezatiostat. Ezatiostat, a glutathione S-transferase P1-1 inhibitor, activates Jun kinase, promoting the growth and maturation of hematopoietic progenitor stem cells. She responded by the end of the first month of treatment with stabilization of her ANC (despite tapering and then stopping G-CSF), clearing of fever, and healing of areas of infection. This ANC response to ezatiostat treatment has now been sustained for over 8 months and continues. These results suggest potential roles for ezatiostat in the treatment of patients with ICN who are not responsive to G-CSF, as an oral therapy alternative, or as an adjunct to G-CSF, and further studies are warranted.

The effect of recombinant granulocyte colony-stimulating factor on oral and periodontal manifestations in a patient with cyclic neutropenia: a case report

Cyclic Neutropenia (CN) is characterized by recurrent infections, fever, oral ulcerations, and severe periodontitis as result of the reduced host defences. The previous studies have established the effectiveness of recombinant granulocyte colony-stimulating factor (GCSF) to increase the number and the function of neutrophils in the peripheral blood in this disease. In a 20-year-old Caucasian female with a diagnosis of cyclic neutropenia, oral clinical examination revealed multiple painful ulcerations of the oral mucosa, poor oral hygiene conditions, marginal gingivitis, and moderate periodontitis. The patient received a treatment with G-CSF (Pegfilgrastim, 6 mg/month) in order to improve her immunological status. Once a month nonsurgical periodontal treatment was carefully performed when absolute neutrophil count (ANC) was ≥500/μL. The treatment with G-CSF resulted in a rapid increase of circulating neutrophils that, despite its short duration, leaded to a reduction in infection related events and the resolution of the multiple oral ulcerations. The disappearance of oral pain allowed an efficacy nonsurgical treatment and a normal tooth brushing that determined a reduction of probing depth (PD ≤ 4 mm) and an improvement of the oral hygiene conditions recorded at 6-month follow-up.

Review of lithium effects on brain and blood

Clinicians have long used lithium to treat manic depression. They have also observed that lithium causes granulocytosis and lymphopenia while it enhances immunological activities of monocytes and lymphocytes. In fact, clinicians have long used lithium to treat granulocytopenia resulting from radiation and chemotherapy, to boost immunoglobulins after vaccination, and to enhance natural killer activity. Recent studies revealed a mechanism that ties together these disparate effects of lithium. Lithium acts through multiple pathways to inhibit glycogen synthetase kinase-3beta (GSK3 beta). This enzyme phosphorylates and inhibits nuclear factors that turn on cell growth and protection programs, including the nuclear factor of activated T cells (NFAT) and WNT/beta-catenin. In animals, lithium upregulates neurotrophins, including brain-derived neurotrophic factor (BDNF), nerve growth factor, neurotrophin-3 (NT3), as well as receptors to these growth factors in brain. Lithium also stimulates proliferation of stem cells, including bone marrow and neural stem cells in the subventricular zone, striatum, and forebrain. The stimulation of endogenous neural stem cells may explain why lithium increases brain cell density and volume in patients with bipolar disorders. Lithium also increases brain concentrations of the neuronal markers n-acetyl-aspartate and myoinositol. Lithium also remarkably protects neurons against glutamate, seizures, and apoptosis due to a wide variety of neurotoxins. The effective dose range for lithium is 0.6-1.0 mM in serum and >1.5 mM may be toxic. Serum lithium levels of 1.5-2.0 mM may have mild and reversible toxic effects on kidney, liver, heart, and glands. Serum levels of >2 mM may be associated with neurological symptoms, including cerebellar dysfunction. Prolonged lithium intoxication >2 mM can cause permanent brain damage. Lithium has low mutagenic and carcinogenic risk. Lithium is still the most effective therapy for depression. It "cures" a third of the patients with manic depression, improves the lives of about a third, and is ineffective in about a third. Recent studies suggest that some anticonvulsants (i.e., valproate, carbamapazine, and lamotrigene) may be useful in patients that do not respond to lithium. Lithium has been reported to be beneficial in animal models of brain injury, stroke, Alzheimer's, Huntington's, and Parkinson's diseases, amyotrophic lateral sclerosis (ALS), spinal cord injury, and other conditions. Clinical trials assessing the effects of lithium are under way. A recent clinical trial suggests that lithium stops the progression of ALS.

Occurrence of periodic oscillations in the differential blood counts of congenital, idiopathic, and cyclical neutropenic patients before and during treatment with G-CSF

Using techniques developed in astrophysics to deal with unequally sampled data sets, we have analyzed serial differential cell counts from 45 congenital, idiopathic, and cyclic neutropenic patients before and during treatment with recombinant human G-CSF (rhG-CSF). Our results show that the occurrence of significant cycling in the absolute neutrophil count (ANC) of neutropenics not classified as cyclical is much more prevalent than had been previously thought, and that not all the patients classified as cyclic show significant ANC periodicity. In these patients, cycling in more than one cell line may be involved. The range of periods encountered in these patients is much broader (between 11 and 52 days) than is usually associated with classical cyclical neutropenia, and there is no obvious connection between the range of periods and the patient's diagnostic category. Administration of rhG-CSF is able to induce significant cycling in neutropenic patients that were not cycling prior to treatment. In patients who had significant cycling before treatment, rhG-CSF may either decrease the period to between 11 and 14 days, or may obliterate any statistical evidence of cycling.

Cyclical Neutropenia and Other Periodic Hematological Disorders: A Review of Mechanisms and Mathematical Models

Although all blood cells are derived from hematopoietic stem cells, the regulation of this production system is only partially understood. Negative feedback control mediated by erythropoietin and thrombopoietin regulates erythrocyte and platelet production, respectively, but the regulation of leukocyte levels is less well understood. The local regulatory mechanisms within the hematopoietic stem cells are also not well characterized at this point. Because of their dynamic character, cyclical neutropenia and other periodic hematological disorders offer a rare opportunity to more fully understand the nature of these regulatory processes. We review the salient clinical and laboratory features of cyclical neutropenia (and the less common disorders periodic chronic myelogenous leukemia, periodic auto-immune hemolytic anemia, polycythemia vera, aplastic anemia, and cyclical thrombocytopenia) and the insight into these diseases afforded by mathematical modeling. We argue that the available evidence indicates that the locus of the defect in most of these dynamic diseases is at the stem cell level (auto-immune hemolytic anemia and cyclical thrombocytopenia seem to be the exceptions). Abnormal responses to growth factors or accelerated cell loss through apoptosis may play an important role in the genesis of these disorders.

© 1998 by The American Society of Hematology.

Cyclical Neutropenia and Other Periodic Hematological Disorders: A Review of Mechanisms and Mathematical Models

Although all blood cells are derived from hematopoietic stem cells, the regulation of this production system is only partially understood. Negative feedback control mediated by erythropoietin and thrombopoietin regulates erythrocyte and platelet production, respectively, but the regulation of leukocyte levels is less well understood. The local regulatory mechanisms within the hematopoietic stem cells are also not well characterized at this point. Because of their dynamic character, cyclical neutropenia and other periodic hematological disorders offer a rare opportunity to more fully understand the nature of these regulatory processes. We review the salient clinical and laboratory features of cyclical neutropenia (and the less common disorders periodic chronic myelogenous leukemia, periodic auto-immune hemolytic anemia, polycythemia vera, aplastic anemia, and cyclical thrombocytopenia) and the insight into these diseases afforded by mathematical modeling. We argue that the available evidence indicates that the locus of the defect in most of these dynamic diseases is at the stem cell level (auto-immune hemolytic anemia and cyclical thrombocytopenia seem to be the exceptions). Abnormal responses to growth factors or accelerated cell loss through apoptosis may play an important role in the genesis of these disorders.

© 1998 by The American Society of Hematology.

The effect of continuous G-CSF application in human cyclic neutropenia: a model analysis

Human cyclic neutropenia (CN) is a rare haematological disorder characterized by oscillations of blood neutrophils at subnormal levels with a stable period of approximately 21 d. During the phase of severe neutropenia (neutrophils < 250 cells/microliters), which last 4-10 d, the patients are endangered by serious infections. Several authors report that continuous G-CSF application can elevate the blood neutrophils to such a level that the risk of infections is significantly reduced. Although the characteristic cycles are not eliminated by G-CSF, the period of the oscillations is shortened to 12-14 d. Based on a previously proposed computer-simulation model of human CN, the effects of continuous G-CSF application on CN are studied. It is shown how the known different cell-kinetic effects of G-CSF on granulopoiesis explain the clinical data in CN. The reduced length of the cycles emerges as a result of the transit time reduction of the post-mitotic granulopoietic cells by G-CSF. The measured increase of the neutrophil maxima is reproduced by the additional mitoses of the immature granulopoietic bone marrow cells induced by G-CSF. The slight elevation of the neutrophil nadirs can be attributed to a weak effect of G-CSF on the assumed underlying defect in CN (an abnormally small variance of the granulopoietic bone-marrow transit time).

Effect of lithium in immunodeficiency: improved blood cell formation in mice with decreased hematopoiesis as the result of LP-BM5 MuLV infection

Lithium salts have been demonstrated to induce the production of hematopoietic cells following administration in vivo and to minimize the reduction of these cells following treatment with either radiation, chemotherapeutic or antiviral drugs. We have previously demonstrated that lithium, when administered in vivo to immunodeficient mice infected with LP-BM5 MuLV (MAIDS) significantly reduced the development of lymphadenopathy, splenomegaly, and the lymphoma associated with late-stage immunodeficiency disease in this model, and increased the survival of these animals compared to virus-infected controls not receiving lithium. We report here the results of in vivo studies in the MAIDS model that determined the effect of lithium on peripheral blood indices and the number of myeloid (CFU-GM), erythroid (BFU-E) and megakaryocyte (CFU-Meg) hematopoietic progenitors from bone marrow and spleen harvested from immunodeficient mice receiving lithium carbonate (1 mM) placed in their drinking water compared to virus-infected controls not receiving lithium. Time-points evaluated were at weeks 1, 5, 9, 13, 17, and 21 postviral infection. Virus-control mice not receiving lithium demonstrated all the signs that are characteristic of MAIDS, i.e., splenomegaly, lymphadenopathy, hypergammaglobulinemia, reduced hematopoiesis, and death. Infected mice receiving lithium demonstrated diminished presence of splenomegaly, lymphadenopathy, hypergammaglobulinemia, no suppression of hematopoiesis nor mortality. Enhanced hematopoiesis was demonstrated by neutrophilia, lymphocytosis, thrombocytosis, and erythrocytosis that was evident by increased myeloid, erythroid, and megakaryocyte progenitor cells cultured from bone marrow and spleen. These studies further demonstrate that lithium influences the disease process in the MAIDS model and restricts the development of hematopoietic suppression that develops in this retroviral animal model of immunodeficiency.

Reversible adult-onset cyclic haematopoiesis with a cycle length of 100 days

Cyclic neutropenia is the most frequent of the cyclic haematopoietic disorders characterized by its regular 21 d cyclic fluctuations in the number of blood neutrophils, and in many cases simultaneous fluctuations in the other blood cell lines. In this paper we describe a 77-year-old woman with a cyclic pancytopenia including all the myeloid cell lines and to some extent the lymphocytes with a constant and predictable oscillation period of about 100 d. Serial bone marrow biopsies and plasma lactoferrin measurements indicated a similar fluctuating pattern in the bone marrow production of neutrophils. Serial measurements of plasma GM-CSF concentration pointed at a simple feed-back inhibitory system. The condition was present for at least 4 years, after which it gradually improved, although the thrombocyte count still showed a fluctuating tendency after a further 4 years of observation. The clinical consequences were mild symptoms of anaemia and a few episodes of respiratory infections occurring during pancytopenic periods. We think this is the first case described in the literature with this variant of a cyclic haematopoietic disorder. The precise pathophysiological mechanism behind this condition is obscure, but probably it is due to a regulatory disturbance at a very early step in the haematopoietic stem cell hierarchy.

Effects of lithium on dimethyl sulfoxide induced differentiation of HL-60 promyelocytic leukemia cells

The human promyelocytic leukemia cell line, HL-60, was used to investigate the effects of lithium on dimethyl sulfoxide (DMSO)-induced granulocytic differentiation of these cells. Dose-response studies showed an optimal increase of cellular proliferation when cells were incubated with 5 mM lithium for 5 days (127 +/- 5% of DMSO only treated cells). This enhancement in growth was preceded by significantly increased [methyl-3H]thymidine incorporation (143 +/- 4% of DMSO only treated controls) after 2 days. However, no significant changes in the ability of cells to reduce NBT could be detected irrespective of whether the cells were incubated with 1.25% (v/v) DMSO only, or with DMSO plus non-toxic concentrations (less than or equal to 10 mM) lithium. From the results obtained it would appear as if the arrest of growth induced by DMSO and the stimulation of proliferation effected by lithium occurs along independent pathways and that lithium exerts its mitogenic effect prior to the onset of terminal differentiation initiated by DMSO.

Severe combined immune deficiency presenting with cyclic hematopoiesis

At age 2 months a male infant presented with a cyclic clinical syndrome every 14-21 days that included pharyngeal aphthous ulcers, high fever, lymphadenopathy, pallor, and malaise. Serial blood studies indicated cycling of all blood cell elements, compatible with a diagnosis of cyclic hematopoiesis (CH). He also manifested a progressively severe immune deficiency, not described before in human CH. When first studied at age 5 months, he was hypogammaglobulinaemic with normal B lymphocyte numbers. By 6.5 months, he was agammaglobulinaemic. At age 8 months, he developed severe pneumocystis carinii pneumonia, and studies showed a state of severe combined immune deficiency. The patient received a bone marrow transplant from his HLA-identical sister with no preconditioning therapy. Subsequently, normal immune function developed and the cyclic hematopoiesis resolved. The majority of lymphocytes is of donor origin. Persistence of erythrocytes and neutrophils of recipient origin suggests that the hematopoietic stem cells were not abnormal. We speculate that this patient had a primary deficiency of a differentiation factor affecting maturation of lymphoid and myeloid progenitor cells.

Adult-onset cyclic bicytopenia: a case report and review of treatment of cyclic hematopoiesis

A unique case of adult-onset synchronous cyclic neutropenia and thrombocytopenia occurring at six-week intervals is presented. Periods of cytopenia were associated with fever, myalgias, gastrointestinal symptoms, and mild mucocutaneous bleeding. Alternate-day steroid treatment failed to correct the periodic fluctuations in peripheral blood counts but ameliorated symptoms during cytopenia. The treatment of cyclic hematopoiesis is reviewed.

Cyclic neutropenia: a clinical review

Cyclic neutropenia is a benign, hematologic disorder characterized by recurrent episodes of severe neutropenia at 21 day intervals. There are associated cyclical variations in other blood cells. Patients with this disease have malaise, stomatitis, cervical lymphadenopathy and fever during the recurrent neutropenic periods. The exact cause of cyclic neutropenia is unknown. About one third of human cases appear to be inherited in an autosomal dominant pattern. In the other cases, the disease appears to arise spontaneously with symptoms usually beginning in infancy or early childhood. In adult patients, the disease may be acquired and occur in association with a clonal proliferation of large granular lymphocytes. Clinical studies in man and investigations in grey collie dogs, which have a very similar disease, strongly suggest that cyclic neutropenia is due to an abnormality in the regulation of early hematopoietic precursor cells. Therapy for cyclic neutropenia involves local and symptomatic therapy for the recurrent mouth ulcers and pharyngitis, and antibiotics for episodes of sinusitis, pneumonia, peritonitis, or bacteremia. Therapy with glucocorticosteroids, androgens, and plasmapheresis has been efficacious in a few adult patients, but no therapy has been proven to alter the cycling of blood counts in children. Despite their repetitive illnesses, patients with cyclic neutropenia grow and develop normally. With the help of attentive physicians and dentists, their quality of life and life expectancy are good. Current research on hematopoietic growth factors offers promise of new approaches to therapy.

Adult-onset cyclic neutropenia is a benign neoplasm associated with clonal proliferation of large granular lymphocytes

Human cyclic neutropenia occurs in children and adults. Adult-onset cyclic neutropenia is an acquired disease characterized by increased numbers of large granular lymphocytes (LGL), in contrast to childhood-onset cyclic neutropenia in which LGL counts are normal. We investigated the clonality of lymphocytes in these two groups of patients by assessing the rearrangement status of the T cell receptor beta chain gene. Patients with adult-onset cyclic neutropenia showed clonal rearrangement of the T beta gene whereas the children did not. Since LGL are known to have multiple regulatory effects on normal hematopoiesis, the finding of a clonal proliferation of this lymphocyte population implicates these cells in the pathogenesis of cyclic neutropenia.

Cyclical neutropenia and T8 lymphocyte mediated stimulation of granulopoiesis

A 33-year-old female with cyclical neutropenia and a reciprocally cycling T8 (suppressor/cytotoxic) lymphocytosis was investigated. T8 lymphocytes ranged between 1.4 and 5.6 X 10(9)/l and a significant proportion (50-75%) were preactivated (1a+). Fc gamma receptors were detected in only a minority (7-10%). Functional studies on the lymphocytes indicated that despite their phenotype, little natural killer and reduced suppressor activities were present. Anti-granulocyte antibodies were not detectable in the serum. Production of colony stimulating activity (CSA) was assessed in the patient and control subjects' lymphocytes. Using a methylcellulose marrow culture system, the CSA production by the patient's lymphocytes was markedly increased compared with the control. Monoclonal antibody cytotoxic experiments confirmed that the T8 lymphocytes were responsible. As peaks of circulating T8 lymphocytes were synchronous with granulopoietic activity in the marrow, the above findings may represent a homeostatic mechanism which is attempting to compensate for an underlying stem cell defect.

Circulating T-cell subpopulations in lithium-associated granulocytosis

Granulocytosis is a common feature in patients undergoing lithium therapy. With increasing evidence that T lymphocytes play a role in the control of granulopoiesis, we have investigated the effect of lithium administration on circulating levels of T helper and T suppressor cells, as identified by monoclonal antibodies, to determine whether lithium-induced granulocytosis is mediated through changes in peripheral blood T cell subsets. Lithium carbonate was administered to 10 subjects over a 2 week period. Differential leucocyte counts and T, B, T helper and T suppressor lymphocyte enumerations were performed prior to administration of lithium (Day 1) and on 2 occasions (Day 7 and 14) during ingestion of the drug. Ten healthy control subjects were similarly investigated. Small, but significant elevation (p less than 0.05) in neutrophil counts at 7 and 14 days were observed in subjects taking lithium, serum lithium levels at these times were 0.56 +/- 0.27 and 0.68 +/- 0.17 mmol/l, respectively; lymphocyte and monocyte levels were unaffected. The percentages and absolute numbers of circulating T, B, T helper and T suppressor lymphocytes were not significantly altered (p greater than 0.05) during lithium administration and did not differ significantly (p greater than 0.05) from those recorded for the control group. We were thus unable to demonstrate that short-term lithium administration induced changes in the circulating levels of T helper (OKT4+) or T suppressor (OKT8+) cells.