Page 23 - Haematologica Vol. 107 - September 2022

REVIEW ARTICLE - ITP: diagnosis and second-line treatment J.B. Bussel and C.A. Garcia Table 2. Considerations regarding severe acute respiratory syndrome coronavirus-2 and second-line treatments for immune
thrombocytopenia.
Second-line option
COVID Infection
SARS-CoV-2 vaccination prior to initiation of ITP second-line treatment
SARS-CoV-2 vaccination after ITP second-line treatment
Rituximab
Limited information on effects of rituximab during active COVID infection89
Patients may be good candi- dates for administration of anti-SARS-CoV-2 antibodies via convalescent plasma or engineered monoclonal antibodies44
Vaccinations should be given prior to starting rituximab e.g. Moderna
a minimum of 5 weeks prior, Pfizer
a minimum of 6 weeks prior
If not vaccinated prior to star- ting rituximab, need to wait to be vaccinated until 6-12 months after completion of last rituximab dose28
TPO Agents
Risk of thrombosis29
Fostamatinib
Potentially useful in COVID in- fections independent of plate- let function47
Immunomodulatory agents
Patients may be good candidates for administration of anti-SARS-CoV-2 antibo- dies via convalescent plasma or engineered monoclonal antibodies44
Vaccination is recommended at least 2-4 weeks prior to starting immuno- suppressive agents44
If the patient is receiving or has received immunosuppres- sive therapy, consider vacci- nation 6 months after the patient has been taken off the- rapy to increase the likelihood of developing immunity44
Splenectomy
*Recommend scree- ning for COVID infec- tion prior
Urgent administration of IV an- tibiotics is mandatory until bacterial cultures are docu- mented as negative, even if the fever is attributed to pro- ven or suspected SARS-CoV- 2 infection44
Vaccination is recommended at least 2-4 weeks prior to the planned sple- nectomy44
Splenectomized persons and those who had received five or more prior lines of therapy were at highest risk of ITP exacerbation29
COVID: coronavirus disease 2019; SARS-CoV-2: severe acute respiratory syndrome coronavirus-2; ITP: immune thrombocytopenia; TPO: thrombopoietin; IV: intravenous.
afterwards to sustain the vaccine effect. If the patient is not vaccinated prior to rituximab treatment, she will not be able to be vaccinated against SARS-CoV-2 for at least 6 if not 12 months;28 this would also apply to a booster vaccination (Table 2). The vaccination might affect her pla- telet count although she is not in a high-risk group which includes those who have had a prior splenectomy and/or five or more lines of previous ITP treatment.29 There is li- mited information on the risk of developing severe COVID in ITP patients undergoing rituximab therapy. In CVID and especially agammaglobulinemia patients, the ability to clear the SARS-CoV-2 virus may be limited, and a patient may remain polymerase chain reaction-positive for weeks or even months.
On the one hand, rituximab with dexamethasone seems a good treatment option because, if she responds well to the four weekly infusions, she can be checked relatively infrequently afterward. On the other hand, the effects on response to SARS-CoV-2 vaccination are clinically signifi-
cant. There appears to have been a marked decrease in rituximab use in ITP since the onset of the COVID pan- demic.
Other immunomodulators
Previously, immunomodulatory agents were widely used second-line treatments, but drawbacks include the need to wait 1-3 months for the platelet count to increase, side effects (depending on the agent) such as hepatic toxicity, and the need to take these medications consistently long- term.5 If a single agent is used, the risk of infection despite the immunosuppression seems very small, but for these agents, efficacy is less than 50%. This group is lumped to- gether as if all agents are the same; it potentially includes mycophenolate mofetil, danazol, dapsone, azathioprine, cyclosporine, and cyclophosphamide.
Recently, a randomized controlled trial of steroids given with or without mycophenolate mofetil within 1 week of the diagnosis of ITP showed that the “cure” rate was
Haematologica | 107 September 2022
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