Differential Diagnosis, Prophylaxis, Treatment of Acute Radiation Syndromes.

2. Hematopoietic Acute Radiation
Syndrome.
 Dmitri Popov, PhD, Advanced Medical Technology
and Systems Inc. , Canada.
 Jeffrey Jones , Professor, Baylor School Of Medicine,
Houston, Texas.
 Maliev Slava, Professor, Vladicaucasian Research
Center of Russian Academy of Science.

3. Acknowledgements
 Carlos Montesinos, Kedar Prasad, Michael Epperly,
Joel Greenberger.

4. Aplastic Anemia
 Aplastic anemia is a disease in which the bone
marrow, and the blood stem cells that reside there, are
damaged.
 This causes a deficiency of all three blood cell types
(Pancytopenia):
 Red Blood Cells - RBC - (anemia),
 White Blood Cells – WBC- (leukopenia),
 Platelets (Thrombocytopenia).
[ Kasper 2005, Merck Manual ]

5. Aplastic Anemia
 Aplastic Anemia is a disorders of the pluripotential
stem cells involve a decrease in the number of cells of
Myeloid,Erythroid and Megakaryotic lineage
 [Segel et al. 2000 ]

6. Etiology
 Etiology of Aplastic Anemia include idiopathic cases
and secondary Aplastic Anemia after exposure to
drugs, toxins, chemicals, Viral Infections, Lympho-prolipherative
Diseases, Radiation, Genetic Causes,
Myelodisplastic Syndromes and Hypoplastic
Anemias, Thymomas, Lymphomas.
 [Brodsky et al. 2005., Modan et al. 1975., Szklo et al.
1975].

7. Hematopoietic Acute Radiation
Syndrome or Radiation Acquired
Aplastic Anemia.
 Hematopoietic Acute Radiation Syndrome(or Bone
marrow syndrome, or Radiation Acquired Aplastic
Anemia ) the Acute Toxic Syndrome usually occurs
with a dose of irradiation between 0.7 and 10 Gy (70 –
1000 rads).
 [ Waselenko e tal., 2004].

8. Forms of H – ARS.
 Hematopoietic (Bone Marrow) Acute Radiation Syndrome.
 Different forms of Hematopoietic Acute Radiation
Syndrome occur at dose > 0.7 Gy (> 70 rads)
(mild symptoms may occur as low as 0.3 Gy or 30 rads)
 Forms of Hematopoietic ARS include
 Moderate form of H- ARS
 Severe form of H – ARS
 Extremely Severe form of H – ARS
 Lethal form of H – ARS.
 death may occur in some individuals at 1.2 Gy (120 rads).

9. Andrews lymphocyte depletion
curves

10. Radiation Effects On Blood Counts.
Fliedner.
 Reversible hematopoietic injury (H1-3 patterns): a
sufficiently large residual viable population of
hematopoietic stem cells (HSCs) remains to
repopulate the bone marrow. As a consequence,
victims will require observation and/or supportive care
but are likely not candidates for HSC transplant.

11. Radiation Effects on Blood Count
 Indicators of H1 injury:
 Lymphocytes remain in the normal range (1.5-3.5) x
109 cells/liter; single lymphocyte counts as low as 1.0 x
109 may be seen.
 Granulocytes remain in normal range (4-9) x
109 cells/liter; a single granulocyte count below normal
range may occur but never below 1.0 x 109 cells/liter.
 Platelets usually remain in the normal range (150-350) x
109 cells/liter; a single platelet count around 100 x
109 cells/liter may be seen, with a potential drop between
days 25 and 35 to the lower border of normal.

12. Radiation Effects On Blood Count
 Indicators of H2 injury:
 Lymphocytes decline from the normal range of (1.5-3.5) x
109 cells/liter within 2 days and remain between (0.5-1.5) x
109 cells/liter.
 Granulocyte levels increase in the first few days, followed by a
drop. Then there is an abortive rise up to the lower limit of
normal. Then cell counts decline slowly to nadir below 1.0 x
109 cells/liter from day 20-30, followed by a variable rate of
rise after days 30-35.
 Platelets remain on low side of normal (100-150) x
109 cells/liter until days 10-12, then nadir to about 50.0 x
109 cells/liter about day 22 for 5-10 days, with regeneration
between days 30 and 32.

13. Radiation Effects On Blood Count
 Indicators of H3 injury:
 Lymphocytes drop within the first 48 hours and remain
between (0.25-1.0) x 109 cells/liter.
 Granulocytes may increase within 1-3 days then decrease until
day 5. An abortive rise may start at around day 5, keeping
levels about 1.0 x 109 cells/liter for about 5-8 days. Then counts
drops to below 0.5 x 109 cells/liter around days 10-15 and
remain at this nadir for about 20 days, with gradual or rapid
increase beginning around days 30-35.
 Platelet counts remain at or above the lower border of the
normal range between (100-150) x 109 cells/liters until days 5-
10. There is a further drop to a nadir of about (0-50) x
109 cells/liter at about day 16-18. The nadir lasts for 12-15 days,
with recovery at variable rate beginning after days 35-40.

14. Radiation Effects On Blood Count
 Irreversible hematopoietic injury (H4 pattern): an
insufficient residual population of HSCs remains to
repopulate the bone marrow either "ever" or within a
short enough time period to withstand the likely
radiation-induced complications from
hypoplasia/aplasia of the blood elements. Supportive
care alone will not salvage this injury, and these
victims are potential candidates for HSC
transplantation.

15. Radiation Effect On Blood Count
 Indicators of H4 injury:
 Lymphocytes decline within first 24 hours and remain between (0.1-
0.25) x 109 cells/liter for weeks.
 Granulocytes may increase within 48 hours, then counts decline
rapidly reaching values of ≤0.5 x 109 cells/liter, with this nadir
persisting.
 Platelets decline over the first 10 days and remain low.
 Although victims with H4 injury should be evaluated for
potential HSC transplant, transplant efficacy after severe
radiation accidents, such as Chernobyl, has not yet been
proven to improve survival. As techniques for this complex
therapeutic intervention continue to improve, some victims may
derive potential benefit from this therapy. It is strongly suggested
that patients be treated on approved clinical Hematopoietic
Stem Cell transplant protocols

16. Hematopoietic Acute Radiation Syndrome –
blood cells, stem cells – apoptosis or/and
necrosis.
 Moderate and high doses of radiation induces necrosis
of radiosensitive cells with the subsequent formation
of radiation toxins (radiomimetics) and their induced
acute inflammatory processes.
 Radiation Toxins are playing an important role as the
trigger mechanism for inflammation, cell lysis, and
damage to vital cellular structures such as
mitochondria, DNA, ion channels and cell membranes

17. Radiation acquired Apoptosis
 Apoptosis may occur as the result of many signals,
among which include: various types of lympholytic
agents, different chemical agents, and physical factors
which include ionizing radiation.
 Apoptosis does not induce Inflammation.
 Necrosis always induce Inflammation.

18. Radiation acquired Inflammation.
 Acute Radiation Disease (ARD) or Acute Radiation
Syndromes (ARS) are defined as the collective toxic
clinical states observed from the acute pathological
processes in various doses of irradiated mammals; to
include: systemic inflammatory response syndrome
(SIRS), toxic multiple organ injury (TMOI), toxic
multiple organ dysfunction syndromes (TMODS),
and finally, toxic multiple organ failure (TMOF).

19. Etiology and Pathogenesis
 After irradiation the number of marrow CD34+ cells –
multi-potential hematopoietic progenitors and colony
forming unit-granulocyte-macrophage (CFU-GM)
and burst forming unit granulocyte macrophage
(BFU-E) reduced significantly and depend on doses of
irradiation.
 Mechanisms responsible for radiation acquired
marrow cell failure include direct toxicity to
hematopoietic multi-potential cells.

20. Radiation Acquired Aplastic
Anemia
 Hematopoietic Acute Radiation Syndrome developed
after significant doses of radiation and demonstrated
a disorder of blood formation in the marrow. The
number of marrow cD34+ cells – multipotential
hematopoietic progenitors and their derivative colony
– forming unit – granulocyte –macrophage ( CFU-GM)
and burst–forming unit erythroid (BFU-E) reduced
markedly. [KaganWA et al. , Segel et al., Scopes J, et
al.]

21. Experiments:
 Administration of Haemotopoietic Radiation Toxins (SRD-
4) to radiation naive animals in doses 0.1 mg/kg; 0,5 mg/kg;
1 mg/kg; 2 mg/kg; 3 mg/kg up to 30 mg/kg produced
specific toxic reactions with symptoms of the
hematological form of ARS.
 Hematotoxin of SRD-4 isolated from L.S. of irradiated
animals with Hematopoetic form of ARS after single
doseinjection with doses 5 mg/kg, 10 mg/kg, 15 mg/kg, 30
mg/kg activate hematotoxic reactions with destruction of
red blood cells and lysis oof white blood cell and activation
of apoptosis/necrosis of hematopoietic cells progenitors.

22. Hematotoxins
 Is it possible that Acute Radiation Hematopoietic
Syndrome could be induced without radiation?
 Yes !
 Hematotoxic Radiation Toxins induce
development of Acute Hematopoietic Acute
Radiation Syndrome.

23. HematoToxins
 The Hemotopoietic Radiation Toxins (SRD-4) were
administered to radiation naive animals in
doses of 0.1 mg/kg; 0,5 mg/kg; 1 mg/kg; 2 mg/kg; 3
mg/kg, 5 mg/kg, 10 mg/kg, 15 mg/kg
and 30 mg/kg.
 Injection of SRD-4 to experimental animals resulted in
erythrocytopenia,lymphocytopenia, leukocytopenia,
and thrombocytopenia within days to weeks after
injection.

24. Radiation Hematotoxins.
 The development of clinical features of the Acute
Hemotopoietic Syndrome depended on the dose of
SRD-4 Hematopoietic Radiation Toxins injected to
radiation naïve animals.
 Autopsy of those animals that died after injections oof
SRD showed acute or chronic hematotoxic reactions.

25. Radiation Hematotoxins
 The clinical signs were: short-term agitation within 2
hours after administration accompanied by a short-term
leukocytosis which gave way to a progressive,
profound leukopenia, mainly attributable to a decrease
in the absolute number of leukocytes and
lymphocytes, the minimal levels of which were
measured between days 7 and 15 after injection.
 Blood counts exhibited thrombocytopenia
accompanied by progressive erythrocytopenia, which
developed into profound anemia.

26. Hematotoxins
 An extensive blood analysis of the peripheral blood of
the cattle showed that the processes induced by the
SRD-4 injection and the processes occurring after
irradiation were nearly identical.
 Analysis of the clinical reaction to SRD-4
administration, which was assessed on the basis of
body temperature, and heart and respiration rate,
established that all experimental animals showed
reactions of the same type for all the tested doses and
that sheep and horses were more sensitive to the
administered preparation.

27. Radiation Hematotoxins
 Postmortem examination of the animals that died
showed changes characteristic of acute radiation
sickness, accompanied by marked hemorrhage.
Death often will occur secondary to overwhelming
bacterial or fungal sepsis. Some sheep showed areas of
skin epilation on the back and abdomen.

28. Radiation Hematotoxins
 Case# 1 . Species- sheep.
 Hematoxin, SDR-4, isolated from irradiated mammals
with the Hematopoietic form of ARS, was injected via
single dose to non-irradiated mammals. The SRD-4 RT
induced significant changes in white blood cells
(WBC) and red cells profile (RBC).
 Hematoxin injected to non-irradiated sheep in doses 5
mg/kg, 10 mg/kg, 30 mg/kg activated a complex
reaction which included general inflammation,
vascular endothelial cell injury, apoptosis and necrosis
of blood progenitor/ stem cells.

29. Radiation Hematotoxins
 The levels of sheep erythrocytes, leukocytes, lymphocytes,
thrombocytes significantly increased in first hours and day
after single injection of radiation hematotoxin and could be
a result of general inflammation reactions and stimulation
of immune system.
 However the levels of erythrocytes, leukocytes,
lymphocytes, thrombocytes significantly decreased after 72
hours after hematoxin administration and the minimal
level of erythrocytes, leukocytes, lymphocytes were
measured after 168- 360 hours following a single dose
injection of the radiation-induced hematoxin.

30. Radiation Hematotoxins
 Radiation toxin SRD-4 (hematotoxin) induces
development of red cell lysis and apoptosis / necrosis of
white blood cell and red cell progenitors.
 Thrombocytopenia, lymphocytopenia, granulocytopenia ,
ecchymosis, hemorrhage and coagulopathy were important
clinical signs
of the mimicked hematopoietic acute radiation syndrome.
 Other clinical indicators of the Radiation Toxins (RT)
included cutaneous system involvement: including:
cutaneous edemas, blustering, desquamation, hair loss,
ulcer and necrosis.

31. Radiation Hematotoixins
 Hematopoetic RT – are strong hematotoxins.
 Hematopoetic RT can destroy red blood cells and
initiate hemolysis, disrupt the blood clotting system
and cause multi-organ degeneration and tissues
damages.
 Hematopoietic RT possess important activity against
pluripotent stem cells and blood marrow.

32. Radiation Acquired Aplastic
Anemia
 ACUTE RADIATION SYNDROME IN HUMANS RONALD E. GOANS, PhD, MD*; DANIEL
F. FLYNN, MS, MD†
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Accidents, 2 nd ed., New York : CRC Press, Inc.; 2001.
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Stockpile Radiation Working Group. Medical managenent of the acute radiation
syndrome: recommendations of the Strategic National Stockpile Radiation Working
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 Dainiak N, Ricks RC. The evolving role of hematopoietic cell transplantation in
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