  Leprosy (Hansen's) is a disease caused by Mycobacterium leprae. This disease
slowly leads to occurrence of leprae reactions which mainly damage peripheral
nervous system which cause loss of organs. We can prevent occurring leprae
reactions by monitoring the bio-markers involved in it. Motivated by these
observations in this research work we do a exhaustive study dealing with the
quantitative correlations between crucial bio-markers and the Multi Drug
Thearphy (MDT) used in treating the type I lepra reaction. We frame and study a
complex 11 compartment model dealing with the the concentrations of plasma
$c_1(t)$ and effective drug action $c_2(t)$, susceptible schwann cells $S(t)$,
infected schwann cells $I(t)$, bacterial load $B(t)$, and five cytokines
pivotal in Type-1 Lepra reaction: IFN-$\gamma$, TNF-$\alpha$, IL-$10$, IL-$12$,
IL-$15$, and IL-$17$. We explore exhaustively and establish the quantitative
correlations with respect to the optimal drug dosage of the MDT drugs such as
rifampin, clofazimine \& dapsone and the crucial bio-markers involved in type I
lepra reaction. We conclude this work by reitrating the fact that the optimal
drug dosage of the MDT drugs found through these optimal control studies and
the dosage prescribed as per WHO guidelines are almost the same.
