Immunological status in patients with neuroendocrine cell hyperplasia of infancy. CRC chILD-EU

<bold>Background:</bold> Neuroendocrine cell hyperplasia of infancy (NEHI) is a childhood interstitial lung disease of unknown pathophysiology. Data on the immune status of patients (pts) with NEHI are scarce. <bold>Aim:</bold> Evaluation of immunological tests in NEHI pts. <bold>Methods:</bold> Patients with newly diagnosed NEHI were enrolled. White blood cells (WBC), IgA, IgM, IgG and IgG subclasses (IgG_1-4) levels, lymphocyte subsets and complement components C3 and C4 were evaluated. Age-adjusted reference values were applied. Data on infection prevalence and severity were collected. <bold>Results:</bold> 25 pts were included. The median age for NEHI diagnosis was 9 mo (IQR 6-11). Immunological assessment was performed ± 2 mo after diagnosis. <table-wrap><object-id>erj;64/suppl_68/OA4696/TB1</object-id><object-id>T1</object-id><object-id>TB1</object-id><table><colgroup><col></col><col></col><col></col><col></col></colgroup><tbody><tr><td><bold>Test</bold></td><td><bold>Median value</bold></td><td> <bold>Pts with value < LLN,</bold> <bold>n (%)</bold> </td><td> <bold>Pts with value > ULN,</bold> <bold>n (%)</bold> </td></tr><tr><td></td><td><bold>g/l</bold></td><td> </td><td> </td></tr><tr><td>IgA</td><td>27.8</td><td>0</td><td>2(8)</td></tr><tr><td>IgM</td><td>68.3</td><td>0</td><td>6(24)</td></tr><tr><td>IgG</td><td>496</td><td>2(8)</td><td>2(8)</td></tr><tr><td>IgG₁</td><td>3.37</td><td>3(12)</td><td>2(8)</td></tr><tr><td>IgG₂</td><td>1.03</td><td>0</td><td>5(20)</td></tr><tr><td>IgG₃</td><td>0.215</td><td>1(4)</td><td>2(8)</td></tr><tr><td>IgG₄</td><td>0.055</td><td>7(28)</td><td>1(4)</td></tr><tr><td></td><td><bold>mg/dl</bold></td><td></td><td></td></tr><tr><td>C3</td><td>94.2</td><td>10(40)</td><td>0</td></tr><tr><td>C4</td><td>15</td><td>8(32)</td><td>1(4)</td></tr><tr><td></td><td><bold>cell/µl</bold></td><td></td><td></td></tr><tr><td>CD3⁺</td><td>3237</td><td>4(16)</td><td>2(8)</td></tr><tr><td>CD3⁺4⁺</td><td>2271</td><td>3(12)</td><td>1(4)</td></tr><tr><td>CD3⁺8⁺</td><td>807</td><td>5(20)</td><td>4(16)</td></tr><tr><td>CD19</td><td>1145</td><td>4(16)</td><td>5(20)</td></tr><tr><td>NK</td><td>310</td><td>2(8)</td><td>1(4)</td></tr><tr><td>CD3/CD4 ratio</td><td>2.44</td><td>4(16)</td><td>5(20)</td></tr></tbody></table></table-wrap> No changes in WBC were found. Nearly all patients (96%) had at least one abnormality in the immunological tests (84% more than one). The most frequent deviation was a decreased C3 value. The highest variability was observed in lymphocyte subsets, being incorrect in 15 children (60%). All identified deviations were mild. Neither a high frequency nor severity of infections was found in NEHI pts. <bold>Conclusions:</bold> Immunological abnormalities are common in NEHI patients, albeit they are mild and do not lead to an increased infection susceptibility.