Page 2613 - Hematology_ Basic Principles and Practice ( PDFDrive )

2326 Part XIII Consultative Hematology

young children with sickle cell disease, in whom antibiotics should be REFERENCES
initiated as soon as the diagnosis is established. Present recommenda-
tions are that twice-daily oral penicillin V potassium or amoxicillin be 1. Weiss L: The spleen. In Weiss L, editor: Cell, and Tissue Biology: a
continued in sickle cell patients until 5 years of age or 3 years postsple- textbook of histology, ed 6, Baltimore, 1988, Urban & Schwarzenberg,
nectomy. High-risk patients with surgical or functional asplenia, pp 515–538.
including those with diagnoses of thalassemia, Hodgkin disease, other 2. Kanzler B, Dear TN: Hox11 acts cell autonomously in spleen develop-
malignancies, immunodeficiency disease, or chronic graft-versus-host ment and its absence results in altered cell fate of mesenchymal spleen
disease, should receive prophylactic antibiotics unless specific contra- precursors. Dev Biol 234:231–243, 2001.
indications exist. Patients who have a history of pneumococcal post- 3. Brendolan A, Rosado MM, Carsetti R, et al: Development and function
splenectomy sepsis may be considered candidates for life-long daily of the mammalian spleen. Bioessays 29:166–177, 2007.
prophylaxis as well. Whether or not such patients receive prophylactic 4. Mebius RE, Kraal G: Structure and function of the spleen. Nat Rev
antibiotics, and regardless of their immunization status, they may Immunol 5:606–616, 2005.
develop overwhelming infections with other organisms, including 5. Junt T, Scandella E, Ludewig B: Form follows function: lymphoid tissue
gram-negative organisms and Staphylococcus aureus. Some experts microarchitecture in antimicrobial immune defence. Nat Rev Immunol
recommend that at the time of febrile illness, asplenic patients take 8:764–775, 2008.
immediate antibiotics at home before quickly traveling to an emer- 6. Dor FJ, Ramirez ML, Parmar K, et al: Primitive hematopoietic cell
gency room for evaluation. There are no randomized trials to guide populations reside in the spleen: studies in the pig, baboon, and human.
therapy and experts have recommended the use of amoxicillin- Exp Hematol 34:1573–1582, 2006.
clavulanate, cefuroxime axetil, or extended-spectrum fluoroquino- 7. van der Laan AM, Ter Horst EN, Delewi R, et al: Monocyte subset
lones. Updated recommendations should be consulted for specific accumulation in the human heart following acute myocardial infarction
circumstances. and the role of the spleen as monocyte reservoir. Eur Heart J 35:376–385,
The single most important measure to prevent postsplenectomy 2014.
septicemia is education of the patient, family, and physician. Recogni- 8. Grover SA, Barkun AN, Sackett DL: The rational clinical examina-
tion of the risk, the institution of appropriate preventive measures, tion. Does this patient have splenomegaly? JAMA 270:2218–2221,
and the rapid administration of antibiotics to a patient who is 1993.
showing signs of infection (fever and chills) can be lifesaving. 9. Ahmed S, Horton KM, Fishman EK: Splenic incidentalomas. Radiol
Clin North Am 49:323–347, 2011.
10. Haan JM, Boswell S, Stein D, et al: Follow-up abdominal CT is not
Atherosclerosis necessary in low-grade splenic injury. Am Surg 73:13–18, 2007.
11. Hackett S, Chua-anusorn W, Pootrakul P, et al: The magnetic suscep-
The magnitude of the risk for development of atherosclerosis is not tibilities of iron deposits in thalassaemic spleen tissue. Biochim Biophys
clear. 9,30 Appropriate preventive measures include identifying and Acta 1772:330–337, 2007.
minimizing concurrent risk factors, such as obesity, dietary patterns, 12. Juweid ME, Stroobants S, Hoekstra OS, et al: Use of positron emis-
a sedentary lifestyle, and the presence of other hereditary factors that sion tomography for response assessment of lymphoma: consensus of
would predispose to thrombosis. Low-dose aspirin could be consid- the Imaging Subcommittee of International Harmonization Project in
ered, but no data exist regarding its efficacy in this situation. Lymphoma. J Clin Oncol 25:571–578, 2007.
13. Valette F, Querellou S, Oudoux A, et al: Comparison of positron emis-
sion tomography and lymphangiography in the diagnosis of infradia-
CONCLUSIONS AND FUTURE DIRECTIONS phragmatic Hodgkin’s disease. Acta Radiol 48:59–63, 2007.
14. Corazza GR, Ginaldi L, Zoli G, et al: Howell-Jolly body counting
Although very little novel information has emerged about clinical as a measure of splenic function. A reassessment. Clin Lab Haematol
aspects of splenic function in recent years, appreciation of many subtle- 12:269–275, 1990.
ties of splenic function and advances in supportive care in several fields 15. Connell NT, Brunner AM, Kerr CA, et al: Splenosis and sepsis: the
have had significant impacts on the management of disorders of the born-again spleen provides poor protection. Virulence 2:4–11, 2011.
spleen. Better education and more effective immunizations have 16. Yongxiang W, Zongfang L, Guowei L, et al: Effects of splenomegaly and
helped prevent serious complications related to splenic disorders. splenic macrophage activity in hypersplenism due to cirrhosis. Am J Med
Advances in imaging and surgery have transformed the diagnosis and 113:428–431, 2002.
management of congenital and traumatic splenic disorders. 17. Akpek G, Pasquini MC, Logan B, et al: Effects of spleen status on
Enhanced understanding of the complexity of communication early outcomes after hematopoietic cell transplantation. Bone Marrow
interaction between the cells of the immune and hematopoietic Transplant 48:825–831, 2013.
system has improved our appreciation of the molecular, cellular, 18. Mistry PK, Lukina E, Ben Turkia H, et al: Effect of oral eliglustat on
system, and network basis for clinical observations about splenic splenomegaly in patients with Gaucher disease type 1: the ENGAGE
function. The ability of splenic macrophages, in concert with randomized clinical trial. JAMA 313:695–706, 2015.
dendritic cells and B cells, to recognize and ingest a variety of 19. Vannucchi AM, Kiladjian JJ, Griesshammer M, et al: Ruxolitinib versus
microorganisms—even in patients without previous exposure to the standard therapy for the treatment of polycythemia vera. N Engl J Med
pathogens—provides great insight into the reasons that the spleen 372:426–435, 2015.
provides protection against a variety of very specific infections. More 20. Buesing KL, Tracy ET, Kiernan C, et al: Partial splenectomy for hereditary
detailed understanding of the impact of the splenic microenviron- spherocytosis: a multi-institutional review. J Pediatr Surg 46:178–183,
ment on cellular functions, the role of stromal infrastructure on the 2011.
ability of cells to interact with and respond to invading pathogens, 21. Al-Salem AH: Indications and complications of splenectomy for children
and the integration of components of the immune system has con- with sickle cell disease. J Pediatr Surg 41:1909–1915, 2006.
tributed to an appreciation of clinical observations about the role the 22. Dodgion CM, Gosain A, Rogers A, et al: National trends in pediatric
spleen plays in normal biology. The intersection of hematopoiesis, blunt spleen and liver injury management and potential benefits of an
recycling of aging cells, and iron metabolism is most clearly demon- abbreviated bed rest protocol. J Pediatr Surg 49:1004–1008, discussion
strated in the spleen. 8, 2014.
Although not necessary to life under baseline circumstances, 23. Mattioli G, Pini Prato A, Cheli M, et al: Italian multicentric survey
the contribution of the spleen to homeostasis under stress is consider- on laparoscopic spleen surgery in the pediatric population. Surg Endosc
able. Ongoing efforts to preserve and manage splenic function will 21:527–531, 2007.
continue to benefit from enhanced appreciation of the underlying 24. Wluka A, Olszewski WL: Innate and adaptive processes in the spleen.
biology. Ann Transplant 11:22–29, 2006.