Evaluating the Relative Frequency of Fungal Infections in the Serum of Patients with Multiple Sclerosis and Healthy Subjects Using PCR

Various genetic and environmental factors are associated with multiple sclerosis (MS) and its progression. Environmental factors include infectious agents especially fungi. The immunological basis of MS and the effects of fungal infections on the immune system led us to compare the relative frequency of fungal infections in the serum of MS patients with controls.

One-hundred serum samples of patients with MS and control individuals were collected. After the DNA extraction, the specificity and sensitivity of the PCR test for universal fungal primers were investigated. Then, an optimal PCR test was performed on control and patient samples.

In this study, 575 base pairs (bp) of genes were considered as the target product using universal fungal primers. The PCR test was performed to check for the specificity with fungal, bacterial, and viral DNAs, along with fungal DNA replication and other reproductive DNAs. The positive cases were 11 and 4 among 100 patients and 100 healthy samples, respectively. Also, the detection limit in this reaction was 40 copies of DNA. The results using SPSS software and Fisher's exact test showed a significant difference between the two groups (P value= 0.052).

MS patients have a higher relative frequency of fungal infections due to weaker immune systems and immunosuppressive drugs. The presence of an active infectious agent in such patients can increase the duration of the destruction of the nervous system. Therefore, diagnosing the active infectious agent and prescribing an appropriate medication regimen can be considered as a contributing factor in preventing the progression of the disease. Therefore, more studies are needed on the types of effective fungal species and their pathogenesis mechanism.