[CIS PIDD] [cis-pidd] AW: Conflicting complement test results

[Hauck, Fabian Dr.med.]

Dear Mike,

I agreewith you  that normal CH50 is dependent on C2 function and that normal CH50 argues against C2D. However, complement analysis is interference-pone. You should check in a second lab and if results are still conflicting go for genetics. A lot of C2-deficient patientes have reduced IgG2- and IGg4-subclasses (but this will probably not help establishing the diagnosis).

Best reards,

Fabian, Hauner Children Hospital, Munich 

-----Ursprüngliche Nachricht-----
Von: Keller, Michael [mailto:MKeller at childrensnational.org] 
Gesendet: Montag, 21. April 2014 20:50
An: CIS-PIDD
Betreff: [cis-pidd] Conflicting complement test results

Greetings everyone,

We have an odd case, and would be most grateful for everyone's thoughts.

Our patient is a 4-year-old boy with history of mastoiditis complicated by an epidural brain abscess and sinus venous thrombosis at 22 months of age.   Surgical cultures grew streptococcus pneumonia.   He had recurrent sinopulmonary infections, beginning in the second year of life, with multiple ear infections prior to the mastoiditis episode.

He was a full-term infant, born to non-consanguinous parents of Hispanic ancestry.
There is no family history of immune disorders, autoimmune/rheumatologic disorders, early malignancies, or unexplained deaths or miscarriages.

He has had all vaccinations without issue to date.

His workup immediately following the epidural abscess was as follows:

IgG/IgA/IgM normal
S. pneumonia titers protective to 8/14 tested Hib titer protective
C2 level: <10 (normal 22-39 mcg/ml)
C3 149
C4 19
C1q: 1789 units/ml
CH50 initially <12 (confirmed on repeat blood draw)
C2 function: 0

He was started on PenVK prophylaxis after these findings.

Oddly, when I met him roughly a year later, his labs were as follows:

CH50: 217 (176-382)
AH50: 74 (normal 77-159)
Properdin level: 34.6 (22.3-67.6)
C2 level: 20.1
C2 function: 0
IgG 851 mg/dl , IgA 57, IgM 131
The commercial TLR assay was normal.
Lymphocyte flow cytometry was essentially normal: abs CD3 3451, CD3/4: 1906, CD3/8: 1082, CD19 1391, CD16/56(CD3-): 258, CD45RA:CD45RO ratio (within CD4+ Tcells) of 4:1.
S. pneumonia IgG titers were protective to 6/14 tested serotypes N meningitides IgG titers were 4/4 protective VZV, Measles IgG were both protective

He's doing fairly on antibiotic prophylaxis, and his only other medical issues are moderate asthma which improved with flovent use and possible developing ADHD.  He is still on PenVK, and we are boosting him with pneumonax given these results.

I'm a bit puzzled by the conflicting data between the C2 function and the CH50/AH50.    It doesn't make much sense to have relatively intact classical complement activity with absent C2 function.

Thanks in advance!

Mike

---------------
Michael D. Keller MD
Division of Allergy / Immunology
Children's National Health System
111 Michigan Ave NW, Room 1W-314B
Washington, DC 20010
Clinic: 202.476.3016
Office: 202.476.5843
Fax: 202.476.2280
www.childrensnational.org

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message.

---
The CIS-PIDD listserv is supported by the Clinical Immunology Society The science & practice of human immunology

P: +1.414.224.8095
E: info at clinimmsoc.org

Not a member of CIS? Please visit www.clinimmsoc.org to join!

You are currently subscribed to cis-pidd as: fabian.hauck at med.uni-muenchen.de.
To unsubscribe click here: http://lm.clinimmsoc.org/u?id=188256718.ff9fe98296347b85fa9ea70e8561a6f2&n=T&l=cis-pidd&o=44796112
or send a blank email to leave-44796112-188256718.ff9fe98296347b85fa9ea70e8561a6f2 at lists.clinimmsoc.org

---
The CIS-PIDD listserv is supported by the Clinical Immunology Society
The science & practice of human immunology

P: +1.414.224.8095
E: info at clinimmsoc.org

Not a member of CIS? Please visit www.clinimmsoc.org to join!

You are currently subscribed to cis-pidd as: pagid at list.clinimmsoc.org.
To unsubscribe click here: http://lm.clinimmsoc.org/u?id=183939985.3ea13d40a15475ac00ebbd9cd8a37d6d&n=T&l=cis-pidd&o=44797327
or send a blank email to leave-44797327-183939985.3ea13d40a15475ac00ebbd9cd8a37d6d at lists.clinimmsoc.org