ECT, Clozapine, White Blood Cells: New Study From Japan

Out on PubMed, from authors in Japan, is this paper:

Long-lasting leukocytosis in patients with schizophrenia treated with clozapine after electroconvulsive therapy : ECT stabilizes white blood cell count.

Sugita K, Mori Y, Kanemoto K, Sugita S.Sci Prog. 2022 Jul-Sep;105(3):368504221117067. doi: 10.1177/00368504221117067.PMID: 36000301

The abstract is copied below:

Introduction: The present study was conducted to investigate the possible hematologic impact of long-term electroconvulsive therapy (ECT) in patients with drug-resistant schizophrenia and receiving clozapine therapy.

Subjects and methods: In this retrospective study, clinical charts of 57 hospitalized patients with schizophrenia who required clozapine therapy because of active psychotic symptoms resistant to other antipsychotics were examined. For 18 who underwent ECT, the first assessment was conducted at the end of that therapy (average two months after start, 7.68 sessions) and the second two months later. As for the 39 patients who did not undergo ECT, the first and second assessment points were at two and four months, respectively, after a randomly chosen time point.

Results: Multiple regression analysis revealed that modified ECT (m-ECT) (ß = 0.346, p = 0.005), gender (males showed greater increase) (ß = 0.273, p = 0.023), and disease duration (longer associated with greater increase) (ß = 0.258, p = 0.033) were correlated with a change in white blood cell (WBC) count (ΔR2 = 0.277, p < 0.001) at the first assessment point. At the second assessment point, multiple regression analysis showed that m-ECT (ß = 0.262, p = 0.039), gender (males showed greater increase) (ß = 0.264, p = 0.036), and disease duration (longer associated with greater increase) (ß = 0.234, p = 0.068) were again correlated with changed WBC count (ΔR2 = 0.203, p < 0.007).

Discussion: An increase in leukocytes may have a protective influence against the adverse myelosuppressive effects of clozapine. However, a simple mobilization of leukocytes from bone marrow to peripheral circulation may not enhance the immune system, leading to only a masking of the effects of a potential immuno-insufficient state in the treated patient. In either case, should leukocytosis be induced and then remain for an extended period, hematologists, as well as psychiatrists involved in electroconvulsive intervention for clozapine-treated patients, must keep this factor in mind.

Keywords: Clozapine therapy; Electroconvulsive therapy; Schizophrenia; leukocytosis; white blood cell count.

The paper is here.

I approached this paper with eager anticipation, but ended up not being able to make heads or tails of it. There seems to be no there, there. Maybe I just missed it, or maybe it is because this is a pre-print.

Where are the absolute WBC numbers?

In any case, this would be interesting, if ECT could protect against clozapine- induced low WBC. Lithium is also a confounder here, as it increases WBC. A little known factoid is that lithium also increases platelet count :

[Lithium increases platelet count.

Joffe RT, Kellner CH, Post RM, Uhde TW.N Engl J Med. 1984 Sep 6;311(10):674-5. doi: 10.1056/NEJM198409063111016.PMID: 6433195]

Please submit comments if you think I have missed other important aspects of this paper, thanks.