Polymerase chain reaction in the diagnosis of paucibacillary leprosy in Colombia

Leprosy Mailing List – April 16^th, 2011 

Ref:     Polymerase chain reaction in the diagnosis of paucibacillary leprosy in Colombia
From: Cadorna-Castro N., Medellín, Colombia

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 Dear Dr. Noto,

 We have few but interesting experiences with the use of polymerase chain reaction (PCR) to help in the diagnosis paucibacillary (PB) leprosy.  However as you comment there is not a definitive concept about this technique.  

With the RLEP PCR we have detected new patients at early stage of disease; we do active search among high risk population: household contacts.  In our experience we could confirm several difficult cases of PB leprosy using PCR (RLEP 1-2 and RLEP 3-4), i.e:

1. Boy, 5 years old with a hipo-pigmented skin lesion on the leg, bacteriological index (BI) negative, both parents with multibacillary (MB) leprosy.  The PCR from skin biopsy was positive.

2. Boy 17 years old; contact of leprosy patient.  One skin lesion on leg.  It was difficult to evaluate sensitivity on the lesion; we concluded that there was no evident loss of sensitivity.  The BI was negative.  PCR from skin biopsy was positive.

We can use PCR as a complementary diagnostic tool for this kind of cases.  Kindly, find in attachment the paper of Donoghue et al:-

“PCR primers that can detect low levels of Mycobacterium leprae DNA”. 

Donoghue HD, Holton J, Spigelman M.

J Med Microbiol. 2001 Feb;50(2):177-182”.

Best wishes,

Nora Cardona-Castro.

MD. MSc.

Instituto Colombiano de Medicina Tropical.

Universidad CES.