Volume 32, Number 9—September 2026
CME ACTIVITY - Synopsis
Neoehrlichiosis Causing Hemolytic Anemia in Patients Treated with Rituximab, Norway, 2024–2025
Martin Paulson
, Christine Wennerås, Hanne Quarsten, Kristine K. Berg, Anders L. Drivenes, Magnus Moksnes, and Tor Henrik A. Tvedt
, Christine Wennerås, Hanne Quarsten, Kristine K. Berg, Anders L. Drivenes, Magnus Moksnes, and Tor Henrik A. Tvedt
Table
Characteristics, reported symptoms, and biochemical test results at admission, during disease course, and post-treatment with antibiotics for 3 patients with neoehrlichiosis, hemolytic anemia, and splenomegaly, Norway, 2024–2025*
| Characteristic | Patient 1 | Patient 2 | Patient 3 |
|---|---|---|---|
| Age, y/sex |
61/F |
62/M |
48/M |
| Indication for rituximab |
Rheumatoid arthritis |
Myasthenia gravis |
Multiple sclerosis |
| Immunosuppression |
Rituximab 1,000 mg 2×/y |
Rituximab 1,000 mg 2×/y |
Rituximab, 1,000 mg 1×/y |
| Signs and symptoms | |||
| Fever | Yes | No | Yes |
| Night sweats | Yes | Yes | Yes |
| Weight loss | Yes | No | Yes |
| Fatigue | Yes | No | Yes |
| Skin involvement | No | Hyperpigmented rash of the lower extremities | No |
| Vascular involvement | Yes | No | No |
| Hemolysis |
Yes |
Yes |
Yes |
| Direct antiglobulin test |
Negative |
Negative |
Negative |
| Blood biochemistry at admission/peak or nadir during disease course/after treatment (reference range) | |||
| Blood Hb, g/dL | 6.4/5.8/12.1 (11.7–15.3) | 9.6/8.8/14.7 (13.4–17.0) | 13.8/17.5/17.5 (13.4–17.0) |
| Blood platelets × 109/L (145–390) | 416/932/373 | 234/154/314 | 186/241/241 |
| Blood leukocytes × 109 cells/L (3.5–10.0) | 4.75/2.74/6.0 | 4.93/3.32/5.97 | 5.32/5.72/4.19 |
| Blood reticulocytes × 109 cells /L (30–100) | 336/70/120 | 180/48/78 | 103/52/84 |
| Plasma C-reactive protein, mg/L (<5) | 15/92/<1.0 | 3.1/3.4/<1.0 | 11/1.7/<1.0 |
| Plasma ferritin, µg/L (30–400) | 950/8,004/3,274 | 92/41/106 | 362/NA/NA |
| Plasma haptoglobin, g/L (0.50–2.10) | 0.34/<0.10/0.45 | <0.1/<0.1/0.24 | <0.1/<0.1/0.54 |
| Plasma, LDH, U/L (35–210) | 189/261/138 | 286/159/188 | 288/164/173 |
| Plasma, bilirubin (total) µmol/L (<25) | 77/100/20 | 19/10/12 | 19/22/16 |
| Blood type | A RhD+ | NA | NA |
| Plasma IgG, g/L (6.10–14.9) |
7.29/6.91/8.68 |
10.4/NA/NA |
8.63/8.63/9.42 |
| Neoehrlichia mikurensis PCR Ct value (at admission) |
22 |
28 |
25 |
| Largest spleen size before treatment (radiologic imaging) |
13.8-cm coronal length |
17-cm coronal length |
17.7-cm coronal length, hilar width 7.4 cm |
| Treatment and results | |||
| Time from treatment start to improved hemolysis | 30 d to normalization of reticulocytosis and Hb increase >2 g/dL | 60 d to normalization of reticulocytosis and Hb increase >2g/dL | 47 d to normalization of reticulocytosis and Hb increase >2 g/dL |
| Time from treatment to improved symptoms |
Cessation of fever after 3 d |
NA |
Cessation of night sweats and fatigue after 7 d |
| Spleen size posttreatment (radiologic imaging) | Splenectomized | Not evaluated | 14 cm coronal length, hilar width 5.2 cm |
*Ct, cycle threshold; Hb, hemoglobin; LDH, lactate dehydrogenase; NA, not available.
Page created: August 31, 2026
Page updated: August 31, 2026
Page reviewed: August 31, 2026
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