White blood cells (WBC) , hemoglobin (Hgb) , platelets (Plt), aspartate aminotransferase (AST) , alanine aminotransferase (ALT) , urea , and creatinine (Cr) results, before and after administration of rituximab in pemphigus patients, were studied in the author’s present work. This is the first study of its kind. It encompasses 39 therapy-resistant pemphigus patients who were treated at Razi Hospital, Tehran, Iran, from 2008 to 2012.

In the study of Chairwatanatorn et al. in 2003, neutropenia following application of rituximab was tested in 53 patients [1]. All the patients except one were under Hodgkin’s lymphoma treatment. Eight cases of grade 4 neutropenia were observed after 1–5 months of treatment with rituximab . Neutropenia was related with a reduction in neutrophil precursors, except for one of the patients whose bone marrow had hypoplasia.

In a study by Tesfa et al. in 2008, neutropenia occurred 4 or more weeks after rituximab treatment in lymphoma patients [2].

In our study, we investigated the variation of total WBC counts, but variation of specific polymorphonuclear neutrophils (PMN) was not investigated separately. In this study, rituximab did not have a statistically significant effect on the number of WBCs. Also, even after adjustment for the effect of gender and underlying diseases, there is still no significant effect on the number of WBCs. Single-variable analysis showed that application of rituximab would result in significant reduction of WBCs in the patients who used CellCept® (mycophenolate mofetil), so it seems that simultaneous application of these two drugs has a synergistic effect on WBC reduction. Also, this study addressed the effect of rituximab on lab test result variations in the first month after receiving the last dosage of rituximab. While the previously mentioned studies addressed neutropenia after more than 4 weeks, this time interval was not of note in our own study.

A study by Otrock in 2005 addressed two patients who had acute thrombocytopenia after receiving rituximab [3]. These patients had hairy cell leukemia and mantle cell lymphoma. In these patients, thrombocytopenia improved without the need of any treatment, after several days.

A study by Leo et al. was conducted in 2004 in which the mixture of fludarabine, rituximab, and cyclophosphamide was applied for the treatment of follicular lymphoma, and severe thrombocytopenia grades 3 and 4 were observed in the patients [4]. The cytologic and serological analysis was based on direct toxicity of rituximab [4].

In our own study, we do not have an exact number for Plt immediately after application of rituximab. But rather, Plt results before application of rituximab and first follow-up after application of rituximab were compared, in which the first follow-up of the patients was taken in 2–4 weeks after the last administration of rituximab. In our study, rituximab did not have a statistically significant effect on Plt variations.

The effect of rituximab on platelets (even after adjusting for the impact of involved sites and other received adjoins) was not statistically significant.

In our patients with systemic underlying disease, rituximab had a statistically significant impact on reduction of platelets , while in patients with no systemic underlying disease, it did not have any statistically significant effect on major variables. Therefore, it can be concluded that having an underlying disease could make patients vulnerable to platelet reduction as a result of rituximab application.