Lack of relationship between blood groups and clinical outcome (body surface area affected) in patients with pemphigus vulgaris.

Sir,

Associations between blood groups and several diseases are observed in the literature. Some of these have scientific support suggesting a rationale, statistical relation. The association between ABO groups with several malignancies, hypercholesterolemia, thrombosis, myocardial infarction, duodenal ulcer, infections, and autoimmune diseases is reported.[1] Pemphigus vulgaris (PV), a rare autoimmune, blistering disease, related to autoantibodies mainly directed to desmogleins, which lead to loss of keratinocyte adhesion.[2] The association between ABO groups and pemphigus has been proposed but not fully demonstrated. Shahkar et al.,[1] concluded the non-existent relationship between blood groups and the development of PV. The authors carried out a case-control study that showed there is no real association between blood groups and PV, in contrast to the work of Grob and Inderbitzin[3] and Altobella.[4] The authors determined that the presence of a particular blood group, in patients with the disease, does not vary significantly with “healthy” population distribution, which is very important because the relationship between blood groups and skin diseases has been controversial and not yet fully elucidated or explained clearly.

In 2007, Valikhani et al.,[5] showed not only that the ABO and Rhesus blood groups not have a particular distribution in the PV, other than the population, but no such relationship with any of the known variants of pemphigus, at least in Iran, suggesting the authors to conduct a study involving other areas of global demographic.

In Mexico, we conducted a similar study in a tertiary referral center for specialized dermatology consultation. We obtained the ABO and Rhesus blood groups of patients with PV in a period between January 2002 and October 2009, being our hospital a center that collects patients from different parts of Mexico and even South America.

We selected 70 charts of patients with PV [Table 1]. No differences in the presence of a particular blood group in patients with the disease were found (P=0.65). We sought to evaluate if any ABO group correlates with the clinical outcome (body surface area affected) of the patients studied. There were no positive or negative correlation between ABO groups and clinical outcome in PV (P=0.752) [Figure 1].

Table 1

Distribution of blood groups among patients with pemphigus vulgaris

Figure 1

Correlation between ABO groups and clinical outcomes in pemphigus vulgaris patients

We conclude, there is no association between ABO and Rhesus blood groups with PV, demonstrated by observing no differences between the presentations of a specific blood group in the disease. Moreover, there is no association between any ABO groups with the clinical outcome in PV.