Session Information
Session Type: Abstract Submissions (ACR)
Background/Purpose: Rituximab is a monoclonal chimeric antibody targeting the CD20 on the surface of normal and abnormal maturing B cells. Late onset neutropenia (LON) is defined as an unexplained absolute neutrophil count of <1.5X109/liter occurring at a time point at least 4 weeks after therapy. LON following rituximab treatment has been described extensively in hematological malignancies. However it has been reported infrequently in association with rheumatological diseases. To the best of our knowledge only 29 such cases have been published so far in the English literature. The aim of this work is to review cases in Israel and to compare them to published cases in the literature thus adding to the body of knowledge regarding this unusual phenomenon.
Methods: Members of the Israeli Rheumatology Association were encountered by e-mail, requesting reports of cases of LON after therapy with rituximab. Submitted cases were reviewed, with demographics and clinical data collated and tabled. Current cases were compared to previously published rheumatology cases.
Results: Eight episodes in seven patients were reported throughout the country after encounting 150 Israeli rheumatologists. Five of the patients had RA, one SLE and one MCTD. The average neutrophil count was o.275/cubic mm in compare to 0.380/cubic mm in previously published cases. One patient had cellulitis of the forearm and all other patients did not have any infection. Five patients were treated with G- CSF. All patients had complete recovery. In comparison to published cases, a larger percentage were RA patients reflecting current usage of the medication in Israel. The average time to LON diagnosis was 177 days as compared to 148 days in published cases.
Table 1: LON: current series compared to previous published cases
|
Age/Gender |
Dg |
No of tx |
Additional tx |
Days since tx |
WBC (% neu) |
Repeat tx |
Infection |
Action taken |
|
32/F |
RA |
4 |
MTX PRED |
151 |
1100(10) |
Yes |
No |
G-CSF |
|
34/F |
MCTD |
1 |
CYC AZA PRED |
105 |
1000(42) |
Yes |
No |
G-CSF |
|
22/F |
SLE |
1 |
CYC |
240 |
0 |
No |
Cellulitis |
G-CSF |
|
38/F |
RA |
1 |
MTX PRED |
120 |
0 |
No |
No |
G-CSF |
|
68/F |
RA |
1 |
PRED ABITREN |
330 |
1270 (50) |
No |
No |
G-CSF |
|
50/F |
RA |
1 |
MTX HCQ |
138 |
2300 (47) |
Yes |
No |
MTX D/C |
|
51/F (same patient on following year) |
RA |
2 |
HCQ |
180 |
2600 (45) |
No |
No |
|
|
78/F |
RA |
1 |
MTX PRED |
150 |
1800 (39) |
No |
No |
MTX D/C Increase PRED |
|
Published cases average age: 52 17(60%)Females8 (40%)Males
|
RA -12 GPA =12 SLE =3 VASCULITIS=1 JRA=1 |
n/a |
MTX -8 MMF -4 |
148 |
380 neutrophiles |
n/a |
Sepsis- 5 Fever – 3 |
G-CSF – 11 |
TX= treatment Dg = Diagnosis RA = rheumatoid arthritis MCTD = mixed connective tissue disease SLE = systemic lupus erythematosus MTX = Methotrexate Pred = prednisone CYC = cyclophosphamide AZA = azathyoprine HCQ = hydroxychloroquine D/C = discontinued MMF = micophenolate mofetyl
Conclusion: LON is a well described finding and should be taken into consideration when following rheumatological patients treated with rituximab. In most cases it can be managed with a single dose of G-CSF and does not put the patient in an additional risk. Periodic complete blood count monitoring is recommended.
Disclosure:
G. S. Breuer,
None;
M. Z. Ehrenfeld,
None;
I. Rosner,
None;
A. Balbir-Gurman,
None;
D. Zisman,
None;
D. Paran,
None.
ACR Meeting Abstracts - https://acrabstracts.org/abstract/late-onset-neutropenia-after-rituximab-treatment-for-rheumatological-conditions/