Immune deviation in recurrent vulvovaginal candidiasis: correlation with iron deficiency anemia.

BACKGROUND Iron Deficiency Anemia (IDA) has been controversially linked to IL-4 production in previous studies. A predominant Th1 response leads to resistance against recurrent vulvovaginal candidiasis (RVVC), whereas a Th2 response exacerbates the disease. OBJECTIVE To investigate the possible effect of iron deficiency on the host's susceptibility to RVVC as a result of the Th1/Th2 cytokine polarization. METHODS We conducted a case-control study of 92 women in 4 groups based on strict inclusion and exclusion criteria: RVVC+IDA+ group consisted of 23 women with RVVC and IDA; RVVC+ IDA- group consisted of 23 women with RVVC without IDA; RVVC-IDA+ group consisted of 23 women without RVVC and with IDA and RVVC- IDA- group consisted of 23 healthy women. The iron parameters and key cytokines (IFN-γ, IL-10, IL-12, IL-4) were measured in blood samples. RESULTS Comparison of IL-4 production between RVVC+ IDA+ (12.2 ± 1.3 pg/ml) and RVVC+ IDA- (2.4 ± 4.0 pg/ml) groups (p=0.044), between RVVC- IDA+ (14.6 ± 1.7 pg/ml) and RVVC- IDA- (1.28 ± 3.6 pg/ml) groups (p=0.006), between RVVC- IDA+ (14.6 ± 1.7 pg/ml) and RVVC+ IDA-) 2.4 ± 4.0 pg/ml) groups (p=0.009) and also between RVVC+ IDA+ and RVVC- IDA- (1.28 ± 3.6 pg/ml) groups (p=0.03) showed significant differences. We found a significant positive correlation between IL-4 and total iron binding capacity (TIBC, p=0.046) and between serum IL-10 and Hb levels (p=0.041) in the RVVC+ IDA- group. There was also a significant negative correlation between serum IL-4 and levels of serum iron (SI, p=0.041) in the RVVC- IDA- group. CONCLUSION It seems that IDA determines the balance between and the intensity of Th1 and Th2 arms of the immune response and leads to a deviation toward Th2 response which could contribute to recurrence of candidiasis.