CASE REPORT
A white female, aged 22 years, with severe pustular psoriasis
and psoriatic arthritis since the age of 14 years had recalcitrant disease and presented for further treatment
options. She had failed to respond to several treatments in the past including topical steroids, calcipotriene, alefacept, cyclosporine, acitretin, phototherapy, etanercept, and methotrexate.
Upon presentation to our clinic, she was initially started on infliximab 5 mg per kg IV at weeks 0, 2, 6, and then every 8weeks and demonstrated significant improvement. However, she subsequently developed a malar rash and pericarditis, which required hospitalization. An ANA titer was elevated at > 1:1280. She was diagnosed with drug-induced lupus secondary to infliximab therapy and treatment was discontinued.
The patient was then started on ustekinumab. One week after
her first dose she reported that she was pregnant. The first dose had been administered at 6 weeks gestation. Despite the improvement seen with the treatment, ustekinumab was discontinued due to lack of clinical data supporting the medication's
use during pregnancy. The patient was started on topical psoriasis therapy then temporarily lost to follow up. At 22 weeks gestation the patient was admitted to the hospital with erythrodermic
psoriasis with painful skin and joints. After discussion with the patient, her obstetric team, and the rheumatology service,
the decision was made to reinstate ustekinumab therapy and the patient received 2 more injections during her pregnancy,
at 26 and 37 weeks gestation. The patient went on to deliver a healthy boy by normal vaginal delivery at term.
DISCUSSION
Ustekinumab is a human monoclonal antibody that binds to the common p40 subunit of IL-12 and IL-23 and inhibits the action of these cytokines.1 It is a relatively new biologic agent that is used in cases of psoriasis that have failed other treatments. It shows similar efficacy to other biologics for this use and has demonstrated minimal, minor complications.1 However, its safety has not been assessed in human pregnancy and to our knowledge this is the first reported use in such a situation.
Most biologics, including ustekinumab, are rated pregnancy category B. However, safety of these drugs in human pregnancy
has not been formally studied. In fact, most safety data come from case reports and series of the use of these drugs in pregnant women or from spontaneous reports of adverse pregnancy outcomes in treated patients. We report this case of a pregnancy resulting in the uncomplicated birth of a full-term infant because to our knowledge this is the first reported outcome of any type of the use of ustekinumab in a pregnant patient. Case reports of pregnancy outcomes are important because
to date biologics have not been prospectively studied in pregnant women and such studies are unlikely in the future. However, one uneventful pregnancy does not ultimately confirm
a medication's safety for routine use during pregnancy. For example, a case of fatal disseminated Bacillus Calmut-Guerin (BCG) infection following BCG vaccination of a 3-month-old infant
born to a mother who was treated with infliximab during pregnancy was recently reported.2
Interleukin-12 has been shown to affect different aspects of pregnancy. For example, elevated and possibly absent levels of IL-12 have been linked to impaired implantation of an embryo due to the cytokine's effects on uterine physiology.3,4 Additionally,
in prematurely born infants, higher concentrations of IL-12 are associated with lower rates of fetuses that are small for gestational
age.5 An initial report on an IL 12/23 inhibitor similar to ustekinumab used during pregnancy in monkeys described masculinization effects on female monkeys whose mothers were treated with this particular medication.6 On the other hand, a study of ustekinumab treatment during pregnancy and nursing in macaques showed the medication to be safe for fetuses
and neonates in regards to mortality, growth, sexual and morphologic development, and immunologic development.7
