Neutrophils play a vital role in our immune defenses by ingesting, killing, and digesting invading microorganisms. Failure to carry out this role results in immunodeficiency, which manifests itself in the form of recurrent infections.[1] Common causes of neutropenia include autoimmune diseases, drug reactions, chemotherapy, and hereditary disorders.[2] Cyclic neutropenia is a very rare hematological condition and is characterized by regular fluctuations in blood neutrophil counts, leading to periodic neutropenia with a 21-day turnover frequency.[2][3] It is now considered an autosomal dominant disease caused by ELANE gene mutations.[4] The symptoms and clinical manifestation of cyclic neutropenia may range from mild to severe, depending on the degree and duration of neutropenia. The absolute neutrophil count can drop to zero, and these extremely low counts may last for up to three to five days.[5]
Recent research in the field of molecular biology has permitted the discovery of the underlying genetic basis for many inherited diseases.[5] Genetic sequencing in patients with cyclic neutropenia has highlighted mutations at locus 19q13 in the gene for neutrophil elastase. This gene is now referred to as ELANE, and the mutations are consistently found to be present in all patients suffering from cyclic neutropenia but not in their unaffected family members. Some authorities refer to this condition as ELANE associated neutropenia.[5][6]
Cyclic neutropenia is an autosomal dominant disease, so it affects males and females in equal proportions and is familial in some.[4] Although the disorder is often discovered in young children, the condition lasts throughout the lifetime of the patient.[7] There have also been reports of cases where patients presented with acquired cyclic neutropenia, and the disease onset was later in life.[8]
Neutrophils play a pivotal role in the immune defense of the body. Once the neutrophil count is below 1 x 10^9/L, the patient becomes susceptible to recurrent infections.[1] The exact pathophysiological basis of cyclic neutropenia remains unknown, but several studies in the 1950s by Page and Good concluded that the interrupted cell production by the bone marrow may be the main underlying cause of cyclic neutropenia.[9] Subsequent studies also showed that there are cyclic fluctuations in all blood cells. This suggests that the intrinsic defect leading to the disorder is in the hematopoietic stem cells.[10]
Patients with cyclic neutropenia usually have a periodic decrease in absolute neutrophil count (often <.2 x10^9/L), and present with a clinical syndrome characterized by recurrent fever, oral mucosal ulcers, and respiratory infections.[11] Opportunistic infections appear during a reduction in absolute neutrophil count and manifest clinically as fever, oral ulcers, gingivitis, tonsillitis, pharyngitis, dermatological infections, and swollen lymph nodes.[12][13][14] Patients also exhibit periodontitis with alveolar bone loss during childhood. It has been observed that the systemic symptoms of cyclic neutropenia such as recurrent fevers diminish after adolescence, but even adult patients continue to experience oral ulcers, gingivitis, periodontitis, and other infections.[15] Infections usually respond well to antibiotics. Severe infections are very rare. However, long-term follow-up of patients showed that the life-threatening complications encountered were the occurrence of spontaneous peritonitis, segmental bowel necrosis, and septicemia.[8]
Diagnosis and evaluation of cyclic neutropenia are based on clinical symptoms, duration, history of hereditary inheritance, white cell counts, immune function, bone marrow alterations, and weekly differential leukocyte count (DLC). Investigations such as complete blood count, bone marrow biopsy, histopathological studies, tumoral markers, levels of cytokines (granulocyte-colony stimulating factor), chest x-ray, diagnostic ultrasound, and CT scan should be done to rule out other immunodeficiency disorders. DNA studies can be carried out as a confirmatory test for most genetic disorders, including cyclic neutropenia.[1]
The mainstay of treatment and management includes regular monitoring of blood counts, prevention and control of infections through judicious use of antibiotics, oral and dental care, and patient education. Alternate-day corticosteroid regimes have been used successfully to treat recurrent signs and symptoms.[8][12] Most children suffering from severe congenital neutropenia require the long-term administration of granulocyte-colony stimulating factor (G-CSF).[16][17]. G-CSF is now considered a remarkably safe and efficacious treatment for preventing infections and to improve the quality of life in patients suffering from cyclic neutropenia.[18] A recent study has suggested that the combination therapy of G-CSF and high-dose immunoglobulin might be an effective treatment for cyclic neutropenia.[19] Hematopoietic stem cell transplantation (HSCT) is still the ultimate radical treatment, which can permanently correct cyclic neutropenia and is the best long term option for patients who do not respond to G-CSF treatment.[17]
Rare disorders with a presentation similar to cyclic neutropenia are as follows:
The clinical course of cyclic neutropenia is usually benign compared with other conditions with neutropenia.[8] The systemic symptoms of cyclic neutropenia such as recurrent fevers usually diminish after adolescence but even adult patients continue to experience oral ulcers, gingivitis, periodontitis, and other infections.[15] Many patients exhibit periodontitis with alveolar bone loss, during childhood.
Studies show that serious long term complications such as septicemia, spontaneous peritonitis, and segmental bowel necrosis may occur in some patients suffering from cyclic neutropenia.[8]
Patient education about careful oral and dental care and the judicious use of antibiotics are the mainstays of management for cyclic neutropenia. The importance of oral hygiene and regular monthly dental visits should be explained to the patient.[22]
Cyclic neutropenia is a distinctive disorder of unknown etiology, characterized by regularly cycling episodes of neutropenia, which occur about every three weeks.[8] Cyclic neutropenia frequently poses a diagnostic dilemma. These patients may exhibit non-specific signs and symptoms such as recurrent fever, oral ulcers, and infections. The cause of recurrent fever may be due to a myriad of diagnoses including, recurrent tonsillitis, infectious diseases, juvenile idiopathic arthritis, Behçet's disease, and familial mediterranean fever syndrome. The physical exam may reveal the fever, aphthous ulcers, and periodontitis, but the cause is difficult to know without proper diagnostic studies. Over the past few years, hematologists, immunologists, and geneticists have collaborated to bring about the discovery of the genetic and biochemical basis of cyclic neutropenia.[23] While the hematologist is almost always involved in the care of patients with cyclic neutropenia, it is important to consult with an interprofessional team of specialists that include an immunologist, geneticist, radiologist, and dentist. A collaboration of the team, interprofessional communication, care coordination, regular patient follow up visits, including lab tests, periodic dental cleaning, and judicious use of antibiotics are recommended to improve patient outcomes.[24]
[1] | Justiz Vaillant AA,Zito PM, Neutropenia 2020 Jan; [PubMed PMID: 29939524] |
[2] | Aota K,Kani K,Yamanoi T,Momota Y,Ninomiya M,Yumoto H,Azuma M, Management of tooth extraction in a patient with ELANE gene mutation-induced cyclic neutropenia: A case report. Medicine. 2019 Sep; [PubMed PMID: 31574885] |
[3] | Dale DC,Hammond WP 4th, Cyclic neutropenia: a clinical review. Blood reviews. 1988 Sep; [PubMed PMID: 3052663] |
[4] | Horwitz MS,Corey SJ,Grimes HL,Tidwell T, ELANE mutations in cyclic and severe congenital neutropenia: genetics and pathophysiology. Hematology/oncology clinics of North America. 2013 Feb; [PubMed PMID: 23351986] |
[5] | Dale DC,Mackey MC, Understanding, treating and avoiding hematological disease: better medicine through mathematics? Bulletin of mathematical biology. 2015 May; [PubMed PMID: 25213154] |
[6] | Horwitz M,Benson KF,Person RE,Aprikyan AG,Dale DC, Mutations in ELA2, encoding neutrophil elastase, define a 21-day biological clock in cyclic haematopoiesis. Nature genetics. 1999 Dec; [PubMed PMID: 10581030] |
[7] | REIMANN HA,DeBERARDINIS CT, Periodic (cyclic) neutropenia, an entity; a collection of 16 cases. Blood. 1949 Oct; [PubMed PMID: 18139383] |
[8] | Wright DG,Dale DC,Fauci AS,Wolff SM, Human cyclic neutropenia: clinical review and long-term follow-up of patients. Medicine. 1981 Jan; [PubMed PMID: 7453561] |
[9] | PAGE AR,GOOD RA, Studies on cyclic neutropenia; a clinical and experimental investigation. A.M.A. journal of diseases of children. 1957 Dec; [PubMed PMID: 13478297] |
[10] | Guerry D 4th,Dale DC,Omine M,Perry S,Wolff SM, Periodic hematopoiesis in human cyclic neutropenia. The Journal of clinical investigation. 1973 Dec; [PubMed PMID: 4750451] |
[11] | Dale DC, Cyclic and chronic neutropenia: an update on diagnosis and treatment. Clinical advances in hematology [PubMed PMID: 22252620] |
[12] | Boo YJ,Nam MH,Lee EH,Lee KC, Cyclic neutropenia with a novel gene mutation presenting with a necrotizing soft tissue infection and severe sepsis: case report. BMC pediatrics. 2015 Apr 2; [PubMed PMID: 25880377] |
[13] | Germeshausen M,Deerberg S,Peter Y,Reimer C,Kratz CP,Ballmaier M, The spectrum of ELANE mutations and their implications in severe congenital and cyclic neutropenia. Human mutation. 2013 Jun; [PubMed PMID: 23463630] |
[14] | Makaryan V,Zeidler C,Bolyard AA,Skokowa J,Rodger E,Kelley ML,Boxer LA,Bonilla MA,Newburger PE,Shimamura A,Zhu B,Rosenberg PS,Link DC,Welte K,Dale DC, The diversity of mutations and clinical outcomes for ELANE-associated neutropenia. Current opinion in hematology. 2015 Jan; [PubMed PMID: 25427142] |
[15] | Ye Y,Carlsson G,Wondimu B,Fahlén A,Karlsson-Sjöberg J,Andersson M,Engstrand L,Yucel-Lindberg T,Modéer T,Pütsep K, Mutations in the ELANE gene are associated with development of periodontitis in patients with severe congenital neutropenia. Journal of clinical immunology. 2011 Dec; [PubMed PMID: 21796505] |
[16] | Rosenberg PS,Zeidler C,Bolyard AA,Alter BP,Bonilla MA,Boxer LA,Dror Y,Kinsey S,Link DC,Newburger PE,Shimamura A,Welte K,Dale DC, Stable long-term risk of leukaemia in patients with severe congenital neutropenia maintained on G-CSF therapy. British journal of haematology. 2010 Jul; [PubMed PMID: 20456363] |
[17] | Rosenberg PS,Alter BP,Bolyard AA,Bonilla MA,Boxer LA,Cham B,Fier C,Freedman M,Kannourakis G,Kinsey S,Schwinzer B,Zeidler C,Welte K,Dale DC, The incidence of leukemia and mortality from sepsis in patients with severe congenital neutropenia receiving long-term G-CSF therapy. Blood. 2006 Jun 15; [PubMed PMID: 16497969] |
[18] | Dale DC,Bolyard A,Marrero T,Makaryan V,Bonilla M,Link DC,Newburger P,Shimamura A,Boxer LA,Spiekerman C, Long-Term Effects of G-CSF Therapy in Cyclic Neutropenia. The New England journal of medicine. 2017 Dec 7; [PubMed PMID: 29211670] |
[19] | Ishida Y,Higaki A,Tauchi H,Yokota Y,Matsuda H, Disappearance of neutrophil fluctuations in a child with cyclic neutropenia by combination therapy of granulocyte colony-stimulating factor and high-dose immunoglobulin. Acta paediatrica Japonica : Overseas edition. 1995 Jun; [PubMed PMID: 7544058] |
[20] | Trandafir LM,Chiriac MI,Diaconescu S,Ioniuc I,Miron I,Rusu D, Marshall syndrome in a young child, a reality: Case report. Medicine. 2016 Nov; [PubMed PMID: 27858841] |
[21] | Kusuhara K, [Periodic fever, aphthous stomatitis, pharyngitis and adenitis syndrome]. Nihon Rinsho Men'eki Gakkai kaishi = Japanese journal of clinical immunology. 2011; [PubMed PMID: 22041428] |
[22] | Nakai Y,Ishihara C,Ogata S,Shimono T, Oral manifestations of cyclic neutropenia in a Japanese child: case report with a 5-year follow-up. Pediatric dentistry. 2003 Jul-Aug; [PubMed PMID: 13678105] |
[23] | Badolato R,Fontana S,Notarangelo LD,Savoldi G, Congenital neutropenia: advances in diagnosis and treatment. Current opinion in allergy and clinical immunology. 2004 Dec; [PubMed PMID: 15640692] |
[24] | Pernu HE,Pajari UH,Lanning M, The importance of regular dental treatment in patients with cyclic neutropenia. Follow-up of 2 cases. Journal of periodontology. 1996 Apr; [PubMed PMID: 8708974] |