The Modified Camitta Criteria is a clinical scoring system used to determine the severity of aplastic anemia in patients. Aplastic anemia is a condition where the body stops producing enough new blood cells, leading to fatigue, higher risk of infections, and uncontrolled bleeding. 

The Modified Camitta Criteria classifies aplastic anemia into three categories: non-severe, severe (SAA), and very severe (VSAA). The classification is based on bone marrow cellularity and the number of peripheral blood cells (neutrophils, platelets, and reticulocytes). 

This calculator is crucial in guiding treatment decisions and predicting prognosis. For instance, patients with SAA or VSAA often require more aggressive treatment strategies, such as immunosuppressive therapy or hematopoietic stem cell transplantation.

There are no specific exclusion criteria for the use of the Modified Camitta Criteria. However, it should be noted that this scoring system is not applicable to patients with other types of anemia or blood disorders. It is specifically designed for patients with aplastic anemia.

Modified Camitta criteria for aplastic anemia severity

# Criteria
 # Marrow cellularity
A. < 25% or 25-50% with < 30% residual hematopoietic cells
## Neutrophils
B. >= 0.5×10**9/L
C. < 0.5×10**9/L
D. < 0.2×10**9/L
## Platelets
E. >= 20×10**9/L
F. < 20×10**9/L
## Reticulocytes
G. >= 20×10**9/L
H. < 20×10**9/L

# Conditions
- A and ((C and F) or (C and H) or (F and H) or (C and F and H))
- A and ((F or H) or (F and H)) and D
- true