Laboratory studies performed in evaluation of neuropathy in 36 patients with IGT
| Laboratory test performed* . | Normal range . | n . | Abnormal results . |
|---|---|---|---|
| Vitamin B12† | 210–911 pg/ml | 36 | 217 in one patient, methylmalonic acid level normal |
| Thyroid-stimulating hormone† | 0.4–5.0 mU/l | 35 | none |
| Serum protein electrophoresis and immunofixation† | various | 35 | IgG kappa in one patient |
| Anti-nuclear antibody titer | ≤1:40 | 27 | titer 1:160 in one patient |
| HbAlc | 4.1–6.5%‡ | 20 | none |
| Folate | 7.8–17.8 ng/ml | 19 | none |
| Thiamine | 0.2–2.0 μg/dl | 12 | none |
| Rapid plasma antigen | negative | 8 | none |
| Methylmalonic acid | <0.4 μmol/l | 7 | none |
| Rheumatoid factor | <20 IU/ml | 6 | none |
| Extractable nuclear Ab screen (Smith, RNP, SSA, SSB, sclero) | <20 U | 6 | none |
| 24-h urine lead | 0–31 μg/day | 6 | none |
| 24-h urine mercury | 0–15 μg/day | 5 | none |
| 24-h urine arsenic | 0–63.9 μg/day | 4 | none |
| Vitamin B6 | 5–30 ng/ml | 4 | none |
| Laboratory test performed* . | Normal range . | n . | Abnormal results . |
|---|---|---|---|
| Vitamin B12† | 210–911 pg/ml | 36 | 217 in one patient, methylmalonic acid level normal |
| Thyroid-stimulating hormone† | 0.4–5.0 mU/l | 35 | none |
| Serum protein electrophoresis and immunofixation† | various | 35 | IgG kappa in one patient |
| Anti-nuclear antibody titer | ≤1:40 | 27 | titer 1:160 in one patient |
| HbAlc | 4.1–6.5%‡ | 20 | none |
| Folate | 7.8–17.8 ng/ml | 19 | none |
| Thiamine | 0.2–2.0 μg/dl | 12 | none |
| Rapid plasma antigen | negative | 8 | none |
| Methylmalonic acid | <0.4 μmol/l | 7 | none |
| Rheumatoid factor | <20 IU/ml | 6 | none |
| Extractable nuclear Ab screen (Smith, RNP, SSA, SSB, sclero) | <20 U | 6 | none |
| 24-h urine lead | 0–31 μg/day | 6 | none |
| 24-h urine mercury | 0–15 μg/day | 5 | none |
| 24-h urine arsenic | 0–63.9 μg/day | 4 | none |
| Vitamin B6 | 5–30 ng/ml | 4 | none |
Data are n.
Two or fewer patients underwent the following tests, all of which were normal: anti–double-standard DNA titer, anti-Hu titer, anti-sulfatide antigen titer, anti-MAG titer, human immunodeficiency virus 2 titer, Lyme titer, vitamin E, and cryoglobulins. Many tests listed were performed before referral;
tests recommended for all patients evaluated;
highest HbA1c value obtained for these patients was 6.1%.